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HomeMy WebLinkAboutChapter 3Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics Page 3-1 3.1 INTRODUCTION The method and process used to predict growth in the Bozeman area up to the year 2030 is contained in this chapter of the Transportation Plan. By using population, employment and other socioeconomic trends as aids, the future transportation requirements for the Bozeman area were defined. A model of the transportation system for the Bozeman area was built with the additions and changes to the system that are projected to occur up to the year 2030 being applied to the model to forecast the future transportation conditions. From this model, various scenarios were developed to test a range of transportation improvements to determine what affects they would have on the transportation system. 3.2 SOCIO-ECONOMIC TRENDS There is a direct correlation between motor vehicle travel growth and population and economic growth. T?he influx of traffic relating to the MSU campus being located in Bozeman is also of significant concern. The population in Gallatin County has seen significant increases since 1990 and has nearly doubled since 1980. There has been a 55 percent increase in population in Gallatin County between 1990 and 2005 alone. The employment numbers have also seen significant growth; between 1990 and 2005 the employment in Gallatin County has doubled. Table 3-1 and Figure 3-1 show the population and employment numbers for Gallatin County between 1970 and 2005. Table 3-1 Gallatin County Population and Employment Trends (1970-2005) Year Population* Employment** 1970 32,505 13,396 1980 42,865 21,797 1990 50,463 31,978 2000 67,831 51,586 2005 78,262 63,379 *Source: Us Bureau of the Census, Census of Population **Source: US Department of Commerce, Bureau of Economic Analysis, REIS Data Series Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Page 3-2 Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics The population trends within Gallatin County in relation to the incorporated cities and the rural area are shown in Table 3-2 and Figure 3-2. The incorporated cities in Gallatin County are Bozeman, Belgrade, Three Forks, Manhattan, and West Yellowstone. The population has increased significantly in each incorporated city as well as the rural areas since 1980. Bozeman has had a population increase of 44.6 percent between 1990 and 2005, while Belgrade has more than doubled in population in the same time period. Table 3-2 Incorporated Cities in Gallatin County Historic Population Trends (1970-2005) Year County Rural Bozeman Belgrade Three Forks Manhattan West Yellowstone 1970 32,505 13,835 18,670 1,307 1,188 816 756 1980 42,865 21,220 21,645 2,336 1,247 988 735 1990 50,463 24,392 22,660 3,411 1,203 1,059 905 2000 67,831 29,371 27,509 5,728 1,728 1,396 1,177 2005* 78,262 35,943 33,535 7,033 1,845 1,465 1,223 Source: US Bureau of the Census, Census of Population *Population data are estimates 010,00020,00030,00040,00050,00060,00070,00080,00019701980199020002005Figure 3-1Gallatin County Population & Employment TrendsPopulation*Employment* Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics Page 3-3 In recent decades there were other notable changes in Gallatin County’s population. In Gallatin County, and elsewhere in Montana and the nation, the population’s age profile got older. Between 1970 and 2000, the number of county residents under the age of 18 increased by 5,232 persons, residents age 18 to 64 increased by 26,942 persons, and residents 65 and older increased by 3,152 persons. As “Baby Boomers” got older, they simply had fewer children than their parents. The change in age can be seen in Table 3-3. The percentage of each age group is shown graphically in Figure 3-3. From this figure, it is apparent that there has been an increase in the age group of 18-64 and a decrease in people less than 18 years of age. A more detailed age distribution for Gallatin County for the year 2000 is shown in Figure 3-4. 010,00020,00030,00040,00050,00060,00070,00080,000CountyRuralBozemanBelgradeThree ForksManhattanWestYellowstoneFigure 3-2Incorporated Cities in Gallatin CountyHistoric Population Trends (1970-2005)19701980199020002005* Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Page 3-4 Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics Table 3-3 Gallatin County Age Distribution (1970-2000) Year Age Total <18 18-64 65+ 1970 9,667 20,220 2,618 32,505 1980 10,202 29,448 3,215 42,865 1990 12,263 33,709 4,491 50,463 2000 14,899 47,162 5,770 67,831 Change (1970-2000) 5,232 26,942 3,152 35,326 Source: US Bureau of the Census, Census of Population 29.7%62.2%8.1%23.8%68.7%7.5%24.3%66.8%8.9%22.0%69.5%8.5%0.0%10.0%20.0%30.0%40.0% 0.0%60.0%70.0%80.0%90.0%100.0%Percent of Total Population1970198019902000YearFigure 3-3Gallatin County Age Distribution (1970-2000)<1818-6465+ Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics Page 3-5 In 2000, there were 51,586 jobs in Gallatin County. This number is almost four times the amount of 13,396 jobs that existed in 1970. Every sector has seen an increase in jobs since 1970 except for farming. Table 3-4 displays countywide employment by economic sector from 1970 through 2000. This information is shown graphically in Figure 3-5. Table 3-4 Gallatin County Employment Trends by Economic Sector (1970-2000) Economic Sector 1970 1980 1990 2000 Change (1970-2000) Farm 1,212 1,075 1,128 1,193 -19 Agricultural Services & Forestry 106 172 370 882 776 Mining 30 105 174 173 143 Construction 656 1,227 1,805 4,801 4,145 Manufacturing 1,002 1,328 2,030 3,164 2,162 Transportation & Public Utilities 420 772 1,025 1,519 1,099 Wholesale Trade 247 555 1,101 1,692 1,445 Retail Trade 2,394 4,355 6,334 10,733 8,339 Finance, Insurance & Real Real Estate 812 1,622 2,315 3,562 2,750 Services 2,598 4,491 8,527 15,360 12,762 Federal & Civilian Government 454 567 610 580 126 Military 293 279 404 374 81 State & Local Government 3,172 5,249 6,155 7,553 4,381 Total Employment 13,396 21,797 31,978 51,586 38,190 Figure 3-4Gallatin County Age Distribution (2000)55 to 594.0%60 to 642.9%65 to 744.4%75 to 843.1%85+1.0%35 to 4415.6%45 to 5413.7%<55.8%5 to 1716.2%18 to 208.2%21 to 2410.3%25 to 3414.8% Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Page 3-6 Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics An employment breakdown for Gallatin County in 2005 is shown in Figure 3-6. The employment in this graphic is broken out by economic sector based on classification by the North American Industry Classification System (NAICS). This type of classification is the standard for all employment figures after 2000. NAICS classification is a more detailed approach to show employment figures than the economic sector approach. The highest employment sector for Gallatin County based on NAICS is retail. Construction is close behind retail for the second highest employment sector, followed by accommodation and food services. 0 2 46810121416 Number of Jobs (Thousands) Farm Agricultural Services & Forestry Mining Construction Manufacturing Transportation & Public Wholesale Trade Retail Trade Finance, Insurance & Real Estate Services Federal & Civilian Government Military State & Local Government Figure 3-5 Gallatin County Employment Trends by Economic Sector (1970-2000) 1970 1980 1990 2000 Change (1970-2000) Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics Page 3-7 The economic trend data presented in Figure 3-5 and Figure 3-6 is not surprising, given the amount of growth in Gallatin County. There has been a large increase in the amount of part-time jobs, many of which are in the retail and food service industry. The increase in population to Gallatin County has also sparked a large increase in construction and real estate related jobs. The increase in the number of jobs in technical and high end jobs can be partially attributed to an increase in the number of people with college educations. With MSU being located in Bozeman, there are a large number of college graduates that elect to stay in the Bozeman area after they graduate. The fundamental importance of understanding economic trends is that eventually, the numbers and types of jobs correlate to vehicle travel on our transportation system. 8,3827,8176,3265,5874,8234,5323,4023,2722,6452,5142,4432,1641,9001,5811,1661,1528868256465904041789 4501,0002,0003,0004,0005,006,0007,0008,0009,000Number of JobsRetail TradeConstructionAccommodation & FoodState GovernmentProfessional & Technical ServicesHealth Care & Social AssistanceReal Estate, Rental & LeasingOther Services, Except PublicManufacturingLocal GovernmentArts, Entertainment & RecreationAdminsitrateive & Wast ServisesFinance and InsuranceWholesale TradeTaransportation & WarehousingFarm EmploymentInformationEducational ServicesFederal & Civilian GovernmentForestry, Fishing & RelatedMilitaryMiningUtilitiesManagement of Companies &Figure 3-6Gallatin County Employment Trends by NAICS (2005) Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Page 3-8 Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics 3.3 POPULATION AND EMPLOYMENT PROJECTIONS Population and economic projections are used to predict future travel patterns, and to analyze the potential performance capabilities of the Bozeman area transportation system. Projections of the study area’s future population and employment are developed from Gallatin County trends (regression line projections), ongoing Growth Policy discussions, and estimates presented by Woods and Poole Economics, Inc. Three projection scenarios are provided through the year 2030 (the planning horizon) and are discussed below. The first scenario that is presented is referred to as the “Moderate Growth” scenario. This is the scenario that is most likely to occur, based on past trends and what has happened in other Montana community’s over the past thirty years. This scenario was selected as the basis for the transportation modeling. It represents a continuation of the current population and growth trends already observed as presented in Section 3.1, such that adequate services and infrastructure will be planned for if the current levels of development continue. It assumes that the Gallatin County population and economy will grow to the numbers specified by Woods and Poole Economics, Inc. If this growth rate pattern does not develop further, or is not sustained, then demand will not occur as planned for in this Transportation Plan, and projects may be delayed or avoided. A second scenario was also developed, and is referred to as the “Low Growth” scenario. It builds from much of the population and employment trends that were realized in the 1980’s, where growth was fairly flat due to many different circumstances. Lastly, a third growth scenario, referred to as a “High Growth” situation, was developed to reflect a more aggressive growth pattern in both population and employment. This growth trend is patterned after population and employment trends that were realized between 1990 and 2005, where growth was higher than in past years. A breakdown of the population and employment projections produced in each scenario are presented in Table 3-5 and shown graphically in Figure 3-7 and Figure 3-8. Table 3-5 Gallatin County Population and Employment Projections (2005-2030) Year Low Growth Moderate Growth High Growth Population Employment Population Employment Population Employment 2005 78,262 63,379 78,262 63,379 78,262 63,379 2010 84,935 68,277 87,406 69,680 90,727 73,474 2015 92,177 73,554 97,618 76,607 105,187 85,176 2020 100,037 79,238 109,023 84,223 121,930 98,742 2025 108,567 85,362 121,760 92,596 141,350 114,470 2030 117,824 91,959 135,986 101,802 163,863 132,702 Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics Page 3-9 Figure 3-7Gallatin County Population Projections0204060801001201401601801970198019902000201020202030YearPopulation (Thousands)Low GrowthModerate GrowthHigh GrowthHistoricalFigure 3-8Gallatin County Employment Projections0204060801001201401970198019902000201020202030YearJobs (Thousands)Low GrowthModerate GrowthHigh GrowthHistorical Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Page 3-10 Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics 3.4 FUTURE DWELLING UNITS The number of dwelling units is a key component in the traffic model. Dwelling units distribute people throughout the network to given locations. They represent the population and act as a hub for traffic within the network. Having an accurate value for the number of people per dwelling unit helps distribute the traffic more accurately. However, it is often quite difficult to accurately represent the population through dwelling units. This is in part because the number of people per dwelling units varies based on location and can change at any time. The best that can be done is to take an average for the entire network and apply that value to the model. In the year 2005, the population in Gallatin County was 78,262 people according to the 2005 census. The traffic model developed for the greater Bozeman area uses 32,495 dwelling units for Gallatin County. This works out to be approximately 2.41 people per dwelling unit. A recent road impact fee study for Gallatin County showed that there was expected to be 2.41 people per dwelling unit in the year 2030. The City of Bozeman Water Facility Plan shows that, “in 1990 the average number of people per dwelling unit was 2.5, while in 2000 the average number declined to 2.3 people per dwelling unit.” Based on this information, an average of 2.41 people per dwelling unit was used in this plan. It is expected that the average number of people per dwelling unit for the entire Gallatin County will be slightly higher than that of the city of Bozeman alone. It is also expected that the average number of people per dwelling unit for the study area would more accurately reflect the county wide ratio. Based on a value of 2.41 people per dwelling unit, there will be approximately 56,462 total dwelling units in the year 2030. This works out to be 23,967 additional units compared to 2005 numbers. The results up to the year 2030 can be found in Table 3-6. This table represents the estimated projected dwelling units based on 2.41 people per dwelling unit using the previously estimated population from Table 3-5. Table 3-6 Gallatin County Projected Dwelling Units Year Population Dwelling Units* Total Additional 2005 78,262 32,495 0 2010 87,406 36,291 3,797 2015 97,618 40,531 8,037 2020 109,023 45,267 12,772 2025 121,760 50,555 18,061 2030 135,986 56,462 23,967 *Dwelling unit projection based on 2.41 people per dwelling unit Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics Page 3-11 3.5 FUTURE EMPLOYMENT Employment numbers are used in the traffic model to help distribute vehicle traffic as accurately as possible. Places with high levels of employment will tend to generate high levels of vehicle traffic. The traffic generated is based in part on the employment type: either retail or non-retail jobs. Non-retail jobs consist of all types of jobs broken out by the NAICS classifications shown in Figure 3-5 excluding “retail trade.” The “Moderate Growth” scenario presented in Table 3-5 shows an estimated 101,802 total jobs available in the year 2030. This works out to be 38,423 new jobs between 2005 and 2030. Of the 38,423 new jobs in the year 2030, 12,203 (or 32%) are expected to be retail and 26,220 (or 68%) are expected to be non-retail. A summary of the number of projected additional employment can be found in Table 3-7 below. Table 3-7 Gallatin County Projected Additional Employment Year Jobs Retail Non-Retail Total 2005 0 0 0 2010 2,001 4,300 6,301 2015 4,201 9,027 13,228 2020 6,620 14,224 20,844 2025 9,279 19,938 29,217 2030 12,203 26,220 38,423 3.6 ALLOCATION OF GROWTH Montana Department of Transportation’s modeling of future traveling patterns out to the year 2030 planning horizon required identification of future socioeconomic characteristics within each census tract and census block. County population and employment projections were translated to predictions of increases in housing and employment within Gallatin County. To accomplish this task, a “Land Use Advisory Committee” (LUAC) was formed to discuss and reach consensus on the distribution of future housing and employment growth in the planning area. The committee’s membership was comprised of staff from public agencies and utilities familiar with ongoing development trends in Gallatin County. A LUAC meeting was held on August 20th, 2007 to discuss the future development in the planning area. The committee’s work considered recent land use trends, land availability and development capabilities, land use regulations, planned public improvements, and known development proposals. It also included a review of the previous land use assumptions associated with the Belgrade Interchange. Figures 3-9 and 3-10 show where potential dwelling units are expected to be developed up to the year 2030 in Gallatin County. Figures 3-11 thru 3-13 show the projected employment values throughout Gallatin County for the year 2030. 200 300 800 244 75 389 124 5 32 8 32 2 2 1 2 2 5 2 1 2 2 5 171 373 82 217 96 191 6 1 2 5 3 2 2 5 22 0 25,000 12,500 Feet SEE DETAIL (FIGURE 3-10) Gallatin County Additional Future (2030) Dwelling Units Figure 3-9 Greater Bozeman Area Transportation Plan (2007 Update) Note: The values and boundaries shown are estimates based on forecasting techniques only. Actual future values and boundaries may differ from those shown. Legend Detail Area City Boundary Urban Boundary County Boundary Census Block Currently Proposed Additional Dwelling Units (as of 10/07) Additional Forecasted Residential Dwelling Units 100 86 2 2 2 124 24 85 28 2 2 2 9 1 2 2 5 2 3 5 5 2 408 218 445 262 2 500 38 177 91 321 80 3 2 2 2 3 4 26 62 31 4 5 2 53 2 24 4 9 223 300 15 130 132 75 48 400 15 132 132 60 300 244 60 100 25 200 500 300 16 400 400 400 400 400 600 50 190 1213 20 2000 12 10 30 10 135 19 445 120 15 320 129 700 26 280 600192 230 125 75 150 75 100 200 2000 440 847 430 300 617 15 0 10,000 5,000 Feet Gallatin County Additional Future (2030) Dwelling Units Figure 3-10 Greater Bozeman Area Transportation Plan (2007 Update) Legend Detail Area City Boundary Urban Boundary County Boundary Census Block Currently Proposed Additional Dwelling Units (as of 10/07) Additional Forecasted Residential Dwelling Units 100 86 Note: The values and boundaries shown are estimates based on forecasting techniques only. Actual future values and boundaries may differ from those shown. 50 50 100 150 50 200 300 400 0 25,000 12,500 Feet Gallatin County Additional Future (2030) Employment Figure 3-11 Greater Bozeman Area Transportation Plan (2007 Update) SEE DETAIL (FIGURE 3-12) SEE DETAIL (FIGURE 3-13) Legend Detail Area City Boundary Urban Boundary County Boundary Census Block Additional Forecasted Retail Jobs Additional Forecasted Non-Retail Jobs 100 86 Note: The values and boundaries shown are estimates based on forecasting techniques only. Actual future values and boundaries may differ from those shown. 566 2338 630 185 53 918 484 75 30 50 30 30 120 15 3270 3500 188 150 225 250 400 200 100 600 600 300 200 25 25 25 25 25 25 25 25 434 1532 389 626 776 66 1482 63 5075 1180 75 50 25 50 75 200 200 100 75 15 15 15 15 15 15 15 15 75 75 803 0 10,000 5,000 Feet Gallatin County Additional Future (2030) Employment Figure 3-12 Greater Bozeman Area Transportation Plan (2007 Update) Legend Detail Area City Boundary Urban Boundary County Boundary Census Block Additional Forecasted Retail Jobs Additional Forecasted Non-Retail Jobs 100 86 Note: The values and boundaries shown are estimates based on forecasting techniques only. Actual future values and boundaries may differ from those shown. 66 5 480 27225 119 21 33 159 159 78 159 159 203 210 159 30 399 159 54 81 54 51 42 159 159 372 18 78 75 1011 37 308 150 30 156 155 156 90 150 150 150 212 6 30 30 0 3,000 1,500 Feet Gallatin County Additional Future (2030) Employment Figure 3-13 Greater Bozeman Area Transportation Plan (2007 Update) Legend Detail Area City Boundary Urban Boundary County Boundary Census Block Additional Forecasted Retail Jobs Additional Forecasted Non-Retail Jobs 100 86 Note: The values and boundaries shown are estimates based on forecasting techniques only. Actual future values and boundaries may differ from those shown. Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics Page 3-17 3.7 TRAFFIC MODEL DEVELOPMENT All of the characteristics of the various areas of the greater Bozeman area combine to create the traffic patterns present in the community today. To build a model to represent this condition, the population information was collected from the 2000 census, and employment information was gathered from the Montana Department of Labor and Industry, second quarter of 2006, and was carefully scrutinized by local agency planners and MDT modeling staff. The roadway network /centerline information was provided by the Gallatin County GIS office. This information was supplemented by input from staff at the City of Bozeman, Gallatin County, and the Montana Department of Transportation who have substantial local knowledge and were able to increase the accuracy of the base model. The GIS files, population census information, and employment information are readily available. The TransCAD software is designed to use this information as input data. TransCAD has been developed by the Caliper Corporation of Newton, Massachusetts, and version 4.0 was used as the transportation modeling software for this project. TransCAD performs a normal modeling process of generating, distributing and assigning traffic in order to generate traffic volumes. These traffic volumes are then compared to actual ground counts and adjustments are made to “calibrate”, or ensure the accuracy of, the model. This is further explained below: Trip Generation -Trip Generation consists of applying nationally developed trip rates to land use quantities by the type of land use in the area. The trip generation step actually consists of two individual steps: trip production and trip attraction. Trip production and trip attraction helps to “explain” why the trip is made. Trip production is based on relating trips to various household characteristics. Trip attraction considers activities that might attract trip makers, such as offices, shopping centers, schools, hospitals and other households. The number of productions and attractions in the area is determined and is then used in the distribution phase. Trip Distribution -Trip distribution is the process in which a trip from one area is connected with a trip from another area. These trips are referred to as trip exchanges. Mode Split -Mode choice is the process by which the amount of travel will be made by each available mode of transportation. There are two major types: automobile and transit. The automobile mode is generally split into drive alone and shared ride modes. For the Bozeman travel demand model, there were no “mode split” assignments (i.e. all trips are assumed to be automobile mode). Trip Assignment -Once the trip distribution element is completed, the trip assignment tags those trips to the Major Street Network (MSN). The variable that influence this are travel time, length, and capacity. Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Page 3-18 Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics Due to the inherent characteristics of a traffic model, it is easy to add a road segment, or “link”, where none exists now or widen an existing road and see what affect these changes will have on the transportation system. Additional housing and employment centers can be added to the system to model future conditions, and moved to different parts of the model area to see what affect different growth scenarios have on the transportation system. Thus the land use changes anticipated between now and 2030 can be added to the transportation system, and the needed additions to the transportation system can then be identified. Additionally, different scenarios for how the Greater Bozeman area may grow between now and 2030 can be examined to determine the need for additional infrastructure depending upon which one most accurately represents actual growth. Also necessary in the development of a transportation model is the establishment of the modeling area. The modeling area is, by necessity, much larger than the Study Area. Traffic generated from outlying communities or areas contributes to the traffic load within the Study Area, and is therefore important to the accuracy of the model. Additionally, it is desirable to have a large model area for use in future projects. The future year model was developed specifically for the year 2030 planning horizon. The 2030 model is used in this document to evaluate future traffic volumes, since 2030 is the horizon year for this document. The information contained earlier in this Chapter was used to determine the additions and changes to the traffic volumes in 2030. The modeling area was subdivided by using census tracts and census blocks, as previously described in this chapter. Census blocks are typically small in the downtown and existing neighborhood areas, and grow geographically larger in the less densely developed areas. The census blocks & census tracts were used to divide the population and employment growth that is anticipated to occur between now and 2030. Built into the traffic model are assumptions about traffic characteristics. The model assumes that traffic characteristics in the future will be similar to those seen today. Changing factors such as fuel costs, technological advances, and other unknown issues may affect the amount and type of traffic on the road network in the future. The model also assumes that the socio-economic information contained earlier in this chapter will be realized in the year 2030. While this may be a conservative assumption, it does give an indication of potential problem areas within the transportation system that may need to be addressed in the future. The future 2030 model is a useful planning tool to help predict how traffic might behave in the future. Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics Page 3-19 3.8 TRAFFIC VOLUME PROJECTIONS The traffic model was used to produce traffic forecasts for the planning horizon year of 2030. For comparison purpose, traffic model results for the calibration year of 2005 are presented herein on Figure 3-14 and Figure 3-15. Year 2030 traffic volume projections are presented in Figure 3-16 and Figure 3-17. These projections indicate that the traffic volumes on some of the major corridors will increase significantly over the next 25 years. In addition to traffic volumes, the model was used to determine volume to capacity (v/c) ratios. Figure 3-18 and Figure 3-19 show the v/c ratios for the calibration year of 2005; future 2030 v/c ratios are shown on Figure 3-20 and Figure 3-21. A discussion of v/c ratios can be found in Chapter 4. It is important to recognize that the volumes shown on Figure 3-16 16 and Figure 3-17 and v/c ratios shown on Figure 3-20 and Figure 3-21 are based on the “Existing plus Committed” roadway network. In other words, these are the volumes and v/c ratios if no changes to the transportation system are made other than those currently committed to. Similar graphics are presented in Chapter 9 that show future values based on a “recommended” transportation system network. 4100 21900 15100 300 2000 13000 2400 3900 3500 1000 3100 7800 9200 6500 10200 11000 8500 13400 19400 10200 13000 200 300 500 900 100 2500 600 1500 1100 800 1200 1400 1700 2200 700 1000 2000 1300 2100 1600 500 500 200 1300 2200 1500 1700 1300 500 1300 200 100 100 1000 1200 1600 1100 500 SEE DETAIL (FIGURE 3-15) Existing (2005) ADT Traffic Volumes Figure 3-14 Greater Bozeman Area Transportation Plan (2007 Update) Note: Traffic volumes determined through the traffic model were used in locations where current ADT counts do not exist. Legend Detail Area City Boundary Urban Boundary Study Area Boundary 2005 Average Daily Traffic (ADT) 1200 2004 Average Daily Traffic (ADT) 1200 2005 Traffic Model Volume* 1200 > 12,000 12,000 -18,000 18,000 -24,000 24,000 -35,000 > 35,000 0 10,000 5,000 Feet 6900 17100 20000 22300 2200 3600 9600 7900 3400 23800 7300 2600 8100 18300 21900 21200 8300 5200 14900 2500 24100 16200 5100 11200 13300 6900 3000 5800 8800 3300 8800 8200 3500 2500 3900 23200 22000 11200 15900 25100 12200 22200 6000 6000 4800 9200 9200 5000 2900 15100 11300 8400 3000 15500 5800 10700 12300 7500 4400 8800 16700 19000 3800 4300 6100 7400 1800 8900 2200 5800 3000 9800 900 400 600 2500 1800 1300 200 500 5300 1700 1100 1200 100 2100 700 3800 5700 4400 3200 200 400 500 6300 0 5,000 2,500 Feet Existing (2005) ADT Traffic Volumes Figure 3-15 Greater Bozeman Area Transportation Plan (2007 Update) Note: Traffic volumes determined through the traffic model were used in locations where current ADT counts do not exist. Legend Detail Area Urban Boundary City Boundary 2005 Average Daily Traffic (ADT) 1200 2004 Average Daily Traffic (ADT) 1200 2005 Traffic Model Volume* 1200 < 12,000 12,000 -18,000 18,000 -24,000 24,000 -35,000 > 35,000 2600 47200 41200 32100 2100 33500 6500 9000 35500 1500 9200 13400 13800 14100 3100 8500 14300 2340050400 36500 30300 400 1000 100 3800 4600 1200 2000 7500 2500 1400 700 2300 9900 1500 4500 4900 3300 2700 2800 7300 3400 5000 5900 6100 3000 2900 3300 3200 1400 1500 3300 100 1200 800 2400 3000 4400 3900 0 10,000 5,000 Feet SEE DETAIL (FIGURE 3-17) Future (2030) ADT Traffic Volumes Figure 3-16 Greater Bozeman Area Transportation Plan (2007 Update) Note: 2030 Anticipated ADT volumes determined by applying a growth rate to existing ADT count locations. Traffic volumes determined through the traffic model were used in locations where current ADT counts do not exist. Legend 2030 Anticipated Average Daily Traffic (ADT)* 1200 2030 Model Traffic Volume* 1200 < 12,000 12,000 -18,000 18,000 -24,000 24,000 -35,000 > 35,000 Detail Area City Boundary Urban Boundary Study Area Boundary 39900 43100 41200 54200 8700 5000 23300 4900 45400 6700 10900 6300 40100 35200 28600 41400 21100 13300 50000 18000 9400 25200 48500 47900 14600 14000 34200 27000 9700 37300 19800 18300 6900 13000 6700 3800 3800 23000 4100 15000 20800 41700 35300 9900 7600 9100 7100 5300 5300 27800 16000 8800 4600 24400 4700 17900 12800 25900 17500 9600 13400 6600 6600 24600 49300 6100 5100 11400 12000 3100 16600 6900 6900 2100 600 1800 5300 6800 4800 2600 6300 2900 3200 1600 5700 8700 1400 2400 9700 9200 9500 1800 3200 1800 2600 1200 4700 10000 1200 0 5,000 2,500 Feet Future (2030) ADT Traffic Volumes Figure 3-17 Greater Bozeman Area Transportation Plan (2007 Update) LegendDetail Area Urban Boundary City Boundary 2030 Anticipated Average Daily Traffic (ADT)* 1200 2030 Traffic Model Volume* 1200 < 12,000 12,000 -18,000 18,000 -24,000 24,000 -35,000 > 35,000 Note: 2030 Anticipated ADT volumes determined by applying a growth rate to existing ADT count locations. Traffic volumes determined through the traffic model were used in in locations where current ADT counts do not exist. 0.32 0.22 0.02 0.03 0.04 0.08 0.01 0.19 0.11 0.85 0.10 0.15 1.08 0.17 0.34 0.20 0.13 0.12 0.09 0.92 0.33 0.29 0.14 0.26 0.65 0.76 0.54 0.18 0.13 0.02 0.08 0.04 0.21 0.10 0.17 0.02 0.14 0.11 0.11 0.01 0.07 0.17 0.08 0.05 0.10 0.12 0.09 0.04 0.06 0.02 0.05 0.01 0.71 1.12 0.37 0.55 0.09 0.04 0.85 SEE DETAIL (FIGURE 3-19) Existing (2005) V/C Volume to Capacity Ratio Figure 3-18 Greater Bozeman Area Transportation Plan (2007 Update) LegendDetail Area City Boundary Urban Boundary Study Area Boundary Volume /Capacity Ratio 0.25 <0.25 0.25-0.49 0.50-0.74 0.75-1.00 >1.00 Volume to Capacity Ratio (V/C) 0 10,000 5,000 Feet 0.25 0.07 0.29 0.21 0.15 0.64 0.05 0.44 0.18 0.30 0.53 0.66 0.68 0.28 0.04 0.52 0.61 0.68 0.63 0.74 0.38 1.24 0.69 0.67 0.48 0.43 0.93 0.46 0.48 0.42 1.12 0.57 0.77 0.24 0.32 0.04 0.02 0.68 0.61 0.01 0.32 0.25 0.58 0.17 0.13 0.20 0.15 0.28 0.09 0.21 0.10 0.06 0.02 0.17 0.50 0.42 0.22 0.26 0.04 0.11 0.74 0.63 0.51 0.72 0.84 0.40 0.40 0.47 0.35 0.35 0.49 1.05 0.36 0.62 0.32 0.46 0.52 0.29 0.73 0.18 1.02 0.59 0.15 0.25 0.61 0.21 0.51 0.73 0.54 0.25 0.65 0.48 0.66 0.32 0.69 0.03 0 5,000 2,500 Feet Existing (2005) V/C Volume to Capacity Ratio Figure 3-19 Greater Bozeman Area Transportation Plan (2007 Update) LegendDetail Area Volume /Capacity Ratio 0.25 Urban Boundary City Boundary <0.25 0.25-0.49 0.50-0.74 0.75-1.00 >1.00 Volume to Capacity Ratio (V/C) 0.69 0.08 0.04 0.1 0.21 0.39 0.01 2.68 2.79 0.17 0.71 0.62 0.4 0.07 0.11 0.19 0.82 0.13 0.38 2.96 0.54 0.06 0.75 0.28 0.12 1.11 0.77 0.22 0.61 1.15 0.2 1.17 0.49 0.51 0.31 0.25 0.26 0.1 0.13 0.21 0.25 0.28 0.24 0.12 0.17 0.24 0.28 0.61 0.27 0.42 0.01 0.32 1.19 0.25 1.95 1.44 0.37 1.04 2.52 0 10,000 5,000 Feet SEE DETAIL (FIGURE 3-21) Future (2030) V/C Volume to Capacity Ratio Figure 3-20 Greater Bozeman Area Transportation Plan (2007 Update) LegendDetail Area City Boundary Urban Boundary Study Area Boundary Volume /Capacity Ratio 0.25 <0.25 0.25-0.49 0.50-0.74 0.75-1.00 >1.00 Volume to Capacity Ratio (V/C) 0.17 1.00 0.15 1.55 0.05 0.4 0.57 0.25 0.42 0.22 0.52 0.24 1.3 1.29 0.27 1.08 0.91 0.13 0.41 0.6 1.15 1.01 2.38 1.18 1.17 2.1 1.11 1.43 0.48 0.2 0.73 1.39 1.37 1.22 0.11 0.98 0.77 0.78 0.39 0.34 2.07 1.53 0.81 0.79 0.58 1.33 0.83 0.63 0.76 0.59 0.44 1.02 0.56 0.26 0.26 0.52 0.56 0.63 0.1 0.52 0.61 0.15 0.15 0.1 0.81 0.59 0.22 0.27 1.01 0.58 0.44 1.92 0.32 1.25 0.39 0.31 1.73 1.65 0.7 0.8 0.71 2.16 1.45 1.12 1.41 0.55 0.55 0.95 0.51 0.56 0.43 0.92 0.26 0.44 1.00 1.19 0.39 0.79 0.73 0.58 0 5,000 2,500 Feet Future (2030) V/C Volume to Capacity Ratio Figure 3-21 Greater Bozeman Area Transportation Plan (2007 Update) LegendDetail Area Volume /Capacity Ratio 0.25 Urban Boundary City Boundary <0.25 0.25-0.49 0.50-0.74 0.75-1.00 >1.00 Volume to Capacity Ratio (V/C) Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Page 3-28 Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics 3.9 NETWORK ALTERNATIVES TEST RUN ANALYSIS Thirteen (13) scenarios were developed for model alternative test run analysis. Each of the 13 scenarios that were developed involve roadway capacity additions in areas where transportation needs presently exist, or in areas where future investment may be needed as a result of expected population/employment growth. Most scenarios are localized, creating new links or expanding existing facilities in a particular study subarea, with investment effects impacting only a small portion of the study area network, i.e., larger system-wide impacts would not be expected. Because all scenarios involve roadway capacity additions, with the exception of Alternative Scenario (AS-3) – Access Management, scenario analysis is focused on how traffic volume and travel times are shifted on key facilities throughout the area of investment (i.e., no multimodal, land use, or other demand management investment options to reduce the number of trips or traffic volume were directly modeled). The alternatives presented in this section are for modeling purposes only and do not represent actual project recommendations at this time. The analysis of these alternatives was made to give a theoretical idea of how certain network modifications made to the transportation system affect the overall network and surrounding area. Should projects arise in the future along these corridors, design alternatives to those discussed in this section will need to be analyzed to determine the appropriate configuration of the roadways. To complete the scenario analysis, the 2030 Existing plus Committed (E+C) network was compared to 2030 scenario results for each alternative. The 2030 E+C model run consisted of the 2005 base travel model network with the addition of one committed project, a widening on South 19th street, and 2030 socio-economic projections. For each of the 13 alternatives, link-level model output (in GIS format) generated by MDT for the entire model domain was clipped to the Bozeman study area only. Individual links on key roadways were then selected and extracted into a new GIS layer to focus analysis; this was done for each of the 13 scenarios individually. Corresponding link-level data was grouped by roadway facility, and converted to Excel platform for calculation of performance measures which included: ?? Link-level percent-difference in AADT between 2030 E+C and 2030 Scenario, ?? Link-level percent-difference travel time between 2030 E+C and 2030 Scenario, ?? Average AADT by roadway facility, ?? Average travel time by roadway facility, ?? Volume-weighted percent-difference AADT by roadway facility, and ?? Volume-weighted percent-difference travel time by roadway facility. Percent AADT and travel time differences were first calculated for each roadway link, weighted by link traffic volume, and averaged over the length of the roadway. For models as large as the Bozeman travel model being used for the plan update, fluctuations in traffic conditions are often seen at a very refined (link) level with oscillations between positive and negative increases occurring over a small area. In order to normalize this effect and get a sense for overall performance at the facility level, percentage differences were weighted by traffic volume (to provide greater weight to links with the greatest volume and least weight to links with the least volume) and averaged over the facility. AS-4 AS-10 AS-13 AS-1 (a) AS-4 AS-10 AS-4 AS-10 AS-4 AS-1 (c) AS-1 (b) AS-11 0 10,000 5,000 Feet SEE DETAIL (FIGURE 3-23) Travel Demand Model Alternative Scenarios Figure 3-22 Greater Bozeman Area Transportation Plan (2007 Update) Note: AS-4, AS-10, and AS-13 scenarios include all aspects of AS-1 in additon to the links shown. The functional classifications shown are recommended as part of the Transportation Plan and do not reflect the federally approved functional classification criteria which is based on current conditions rather than anticipated future conditions. Legend Interstate Principal Arterial Minor Arterial Collector Local Detail Area City Boundary Urban Boundary Study Area Boundary Alternative Scenario* *The colors shown are for designation of modeling alternatives and do not represent any sort of classification. AS-8 AS-10 AS-7 AS-12 AS-2 AS-9 AS-6 AS-5 AS-4 AS-12 AS-10 AS-7 AS-7 AS-4 AS-12 0 5,000 2,500 Feet Travel Demand Model Alternative Scenarios Figure 3-23 Greater Bozeman Area Transportation Plan (2007 Update) *The colors shown are for designation of modeling alternatives and do not represent any sort of classification. Legend Local Interstate Principal Arterial Minor Arterial Collector Detail Area Urban Boundary City Boundary Alternative Scenario* Note: AS-4, AS-10, and AS-13 scenarios include all aspects of AS-1 in additon to the links shown. The functional classifications shown are recommended as part of the Transportation Plan and do not reflect the federally approved functional classification criteria which is based on current conditions rather than anticipated future conditions. Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics Page 3-31 Alternative Scenario 1 – East Belgrade Interchange The northwest portion of the Bozeman study area shows the highest expected growth in population by 2030, in particular towards Belgrade. Between 2005 and 2030, the north-south principal arterials Jackrabbit and Love both show greater than 200% increase in traffic volume, with east-west facilities between Cameron Bridge and Huffine also showing greater than 200% increase. I-90 west shows a greater than 50% increase in volume closer to the city, with increasing growth in volume towards Belgrade (greater than 200% increase outside of the study area towards Belgrade). New interstate access points must serve a regional purpose in accordance with Federal Highway Administration requirements. The purpose of the proposed East Belgrade Interchange is to facilitate greater intermodal connectivity with the Gallatin Field Airport, not to accommodate local traffic. In addition to serving a regional need, the East Belgrade Interchange project is intended to accommodate the projected volume increase in the north-west portion of the study area. Travel demand modeling completed for this analysis includes the following: ?? Interchange footprint with a connection to Alaska Road (to the south) and the Gallatin Airport entrance (to the north), ?? Connection to Northern Pacific Avenue and also a connection to Frank Road, ?? North Dry Creek Road Bypass which connects to the airport road entrance, and ?? Extension of Love Lane from its terminus at the south to connect to Cameron Bridge Road. Scenario analysis results indicate: ?? Alaska Road, Cameron Bridge, and Love Lane all experience an increase in traffic volume between the 2030 E+C and 2030 AS-1, as indicated in Table 3-8, as trips shift from parallel routes to access I-90 at the new interchange. While Alaska Road experiences a slight increase in travel time of 1.24% due to the volume increase, Cameron Bridge experiences a much greater increase in average weighted travel time of 1081%, from an average travel time of 15 minutes to 51 minutes. It is recommended that an additional capacity connection between the new northern terminus of Love Lane and the new interchange be tested, with the intent of the new capacity connection to draw some of the additional traffic off of Cameron Bridge. Note that Valley Center, which runs parallel to Cameron Bridge, shows a drop in traffic volume of 28% with a corresponding decrease in travel time of 46%. A possible upgrade of Valley Center from a 2-lane collector to a minor arterial could also be tested to divert a portion of trips off of Cameron Bridge, while still providing a direct connection to Alaska and the new interchange. ?? Overall, the average weighted travel time on Love Lane between Huffine and Cameron Bridge drops by almost 100%, despite the 22% increase in traffic volume, as a result of the additional capacity being added at its northern terminus (i.e., additional volume that is shifted to the upgraded facility is not enough to cause total volume to exceed available new capacity, therefore volume/capacity ratios decrease between the 2030 E+C and 2030 AS-1, and travel times decrease). Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Page 3-32 Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics ?? Key parallel facility, Jackrabbit, benefits from a 14% decrease in volume and 7% decrease in travel time, and Harper Puckett benefits from a 26% decrease in volume and 50% decrease in travel time. ?? Both Frontage Road and I-90 show a decrease in traffic volume and travel time with Frontage decreasing in volume and travel time by 21% and 25%, respectively, and I-90 decreasing in volume and travel time by 8% and 3% respectively. This is likely a result of the new interchange facilitating additional trip routing between I-90 and the City of Bozeman onto upgraded, non-interstate (principal arterial) facilities, namely Alaska to Cameron Bridge to Love. Table 3-8 Alternative Scenario 1 -East Belgrade Interchange Roadway Termini AADT % Change Travel Time % Change Alaska Alaska southern termini /I-90 198.45 1.24 Baxter Jackrabbit/Harper Puckett 4.17 14.96 Cameron Bridge Thorpe/Harper Puckett 41.99 1081.39 Frontage Belgrade Interchange/Springhill -21.37 -25.4 Harper Puckett Baxter/Cameron Bridge -26.01 -50.48 Hulbert Jackrabbit/Love -5.67 -0.34 I-90 Gallatin Field/Springhill -7.8 -2.94 Jackrabbit Huffine/Amsterdam -14.09 -6.85 Love Huffine/Cameron Bridge 22.47 -97.86 Valley Center Jackrabbit/Harper Puckett -28.44 -46.09 Alternative Scenario 2 – Northeast Arterial Link The purpose of this model scenario is to assess the traffic related impacts of creating an arterial link in the northeast portion of the City of Bozeman. This scenario includes the following: ?? Extend Highland Boulevard from its current terminus at Main Street north to connect with Cedar Street. This extension is envisioned as a minor arterial link. ?? Extend Oak Street east of Rouse Avenue to connect with Cedar Street. This extension is also envisioned as a minor arterial link. ?? For purposes of continuity in the traffic model, upgrade Cedar Street to a minor arterial link. These three modifications are intended to provide a new important connection to reduce traffic along Main Street, Rouse Avenue and within the Northeast Neighborhood. Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics Page 3-33 Scenario analysis results indicate: ?? Main Street, between 19th and Haggerty, benefits from a 3% decrease in AADT, and a 7% decrease in travel time. Rouse also benefits from a 5% decrease in AADT and a 5% decrease in travel time. ?? Almost all roadways evaluated in the northeast neighborhood see a benefit as indicated in Table 3-9 below. Note Highland experiences a slight increase in AADT of 2% and travel time of 0.5% due to the new capacity connection causing a shift in trips from parallel collectors, Church and Bozeman Trail, to the upgraded, minor arterial Highland. ?? This scenario provides a good example of dispersion of traffic due to well-made capacity connections in an area of expected growth; in this case with the growth occurring in the portion of the City of Bozeman bounded by Kagy, Highland, I-90 and Bozeman Trail, where redevelopment is already occurring to support increased residential development. Traffic is able to be dispersed due to the creation of a gridded system, with several key north-south facilities able to provide comparable level of service and access to I-90; therefore, no disproportionate shift of traffic to one facility over another. Table 3-9 Alternative Scenario 2 -Northeast Arterial Links Roadway Termini AADT % Change Travel Time % Change 7th I-90/Main 0.11 -1.77 Babcock 19th/Wallace -7.96 -2.23 Bozeman Trail Kagy/Haggerty -8.68 -15.1 Broadway Main/Avocado -23.57 -11.29 Church Sourdough/Babcock -8.98 -40.18 Durston 19th/Avocado -2.14 -3.33 Highland Kagy/Cedar 1.55 0.46 Main 19th/Haggerty -3.3 -6.61 Oak 19th/Rouse 18.8 0 Peach 7th/Rouse -19.09 -0.7 Rouse Griffin/Peach -4.6 -4.97 Sourdough Kagy/Church -2.86 -12.08 Tamarack 19th/Wallace -12.16 -16.57 Wallace L/Babcock -23.67 -61.33 Alternative Scenario 3 – Access Management Scenario This scenario involves modeling existing access management plans for Jackrabbit and Huffine. The purpose of this scenario is to define what access management principles can accomplish in providing excess capacity and congestion relief along existing corridors, potentially delaying major capacity upgrades. Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Page 3-34 Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics A 5% increase in capacity was modeled for both Jackrabbit and Huffine with turn prohibitions implemented to local roads without signalized intersections (reference May 27, 2008, Access Management memo). This provides a “surrogate” modeling approach to show the benefit of reducing conflict points between vehicles entering/exiting a roadway and channeling vehicle traffic in a manner that supports smoother traffic flow and increased travel speeds. Scenario analysis results indicate: ?? Huffine benefits from an 11% decrease in traffic volume and a 35% decrease in travel time, while Jackrabbit sees a 6% increase in volume and a corresponding 6% increase in travel time. While it is not unusual to expect a volume increase under this scenario as a result of added capacity improving the function of a facility (thereby pulling more trips to it), an overall decrease in travel time should be expected due to the addition of turn prohibitions that mimic reduced conflict points. ?? As noted in the Access Management modeling memo, when reviewing the network along the two subject corridors for network detail, it was found that the centroid for traffic analysis zone (TAZ) 9595 is located inside the loop ramp in the southwest quadrant of the interchange at Interstate 90 and Jackrabbit Lane. Since no land use activity is located inside this loop ramp, it was recommended that the centroid be moved to more accurately represent the center of activity and loading of trips onto the network. ?? Because there may be an issue with loading of trips in this area, it is recommended that the centroid connector issue be addressed, and that the scenario be re-modeled in the future. It may be beneficial to also model this scenario with the inclusion of the East Belgrade Interchange so that the additional trips drawn to the area as a result of the improved facility can directly access I-90 in another location of close proximity. Table 3-10 Alternative Scenario 3 -Access Management Scenario Roadway Termini AADT % Change Travel Time % Change Alaska Alaska southern termini/I-90 -5.28 -0.13 Baxter Jackrabbit/Harper Puckett -1.23 -3.26 Cameron Bridge Thorpe/Harper Puckett 33.53 953.48 Durston Love/Cottonwood 0.46 24.81 Huffine Zoot/Fowler -10.87 -34.94 Hulbert Jackrabbit/Love -14.46 -1.74 Jackrabbit Huffine/I-90 5.85 6.23 Love Huffine/Valley Center -3.75 -11.12 Valley Center Jackrabbit/Hidden Valley 2.64 18.99 Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics Page 3-35 Alternative Scenario 4 – Arterial Connections /Cross Regional Grid System This scenario involves modifying and/or widening existing roads, and constructing key new roadway segments for facilities that support critical cross-region movement. Upgrades would be to principal arterials only (four-lane and/or five-lane cross sections). This will serve to create a strong grid arterial system. The focus for this would be on the western and southern portions of the study area where there are greatest increases in traffic volumes as a result of expected long-term population and employment growth. Recommended modeling assignments build off of existing key principal arterial corridors (e.g., Jackrabbit/Gallatin between I-90 and Cottonwood, 19th between Nash and I-90, Cottonwood between Johnson and Oak). Modeling included the following upgrades: ?? Upgrade 1 – North/South Connection o Extend existing principal arterial, Love Lane, south to connect to Gooch Hill/Johnson o Upgrade Gooch Hill/Enders south to Cottonwood from Minor Arterial to Principal Arterial o Include all aspects of Alternative Scenario 1 – East Belgrade Interchange ?? Upgrade 2 – East/West Connection o Upgrade existing minor arterial, Cottonwood, between Gallatin and Enders to Principal Arterial o New principal arterial capacity connecting Cottonwood/Enders to Kent Spur o Upgrade Kent Spur from minor to principal arterial ?? Upgrade 3 – North South/Connection o Upgrade Cottonwood/Kent Spur north to Johnson from minor arterial to principal arterial. o Connect Cottonwood between Oak and Harper Puckett – principal arterial o Extension of Cottonwood Road from its current terminus to Valley Center Road (as a principal arterial). ?? Upgrade 4 – North South Connection o Upgrade Gooch Hill and Chapman between Johnson and Durston from minor to principal arterial Scenario analysis results indicate: ?? All key north-south, newly upgraded principal arterial facilities – Jackrabbit /Gallatin, Love /Gooch Hill, Cottonwood /Harper Puckett, and north 19th experience significant travel time benefits, as indicated in Table 3-11. Similar to AS2, but on a larger scale, traffic is able to be evenly dispersed due to the creation of a connected system, with several key north-south facilities able to provide comparable level of service and access to I-90; therefore, no disproportionate shift of traffic to one facility over another. Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Page 3-36 Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics ?? I-90 and Frontage between the new East Belgrade Interchange and 19th also show traffic improvements with 19th showing a 4% decrease in traffic volume and a 3% decrease in travel time, and Frontage Road showing a 19% decrease in volume and 17% decrease in travel time. ?? Similar to the other alternatives where the East Belgrade Interchange in modeled, Alaska sees a significant increase in volume of 219% as trips are shifted to the facility to access I-90 at the new location, and a corresponding increase in travel time of 4%. Cameron Bridge experiences deterioration in level of service of 85% increase in volume and greater than 2500% increase in travel time (from an average travel time of 2 minutes to 23 minutes) as trips are shifted to the area. It is recommended that additional improvements be tested in the area to relieve the induced traffic created on Cameron Bridge, e.g., an additional capacity connection between the new northern terminus of Love Lane and the new interchange, or an upgrade of Valley Center from a 2-lane collector to a minor arterial facility. Valley Center shows a 22% drop in volume and 39% drop in travel time and can likely accommodate shift in additional volume to the facility if it is upgraded. There is an active Environmental Assessment (EA) for Valley Center that calls for the roadway to be widened and turn lanes to be added. ?? Harper Puckett shows an increase in traffic volume of 58% and greater than 2500% increase in travel time (from an average travel time of 2 minutes to 52 minutes), also due to the significant shift in trips to the area. The improvements suggested above, may also serve to alleviate the increase in volume and travel time on Harper Puckett if they reduce the volume increase (bottleneck which is likely occurring) on Cameron Bridge. ?? Key east-west facilities extending between the upgraded north-south principal arterials show both traffic improvements and deterioration, with the majority showing improvement. Durston shows a 17% increase in volume and 9% increase in travel time, while Huffine shows a 6% decrease in volume and 20% decrease in travel time, Main with a 6% decrease in volume and 14% decrease in travel time, and Johnson a 26% and 79% decrease in volume and travel time, respectively. Oak shows a 93% increase in volume, but 90% decrease in travel time as the addition of new capacity causes trips and volume to shift to the upgraded facility; however this volume increase is not enough to exceed available (new) capacity allowing the volume/capacity ratio to drop and average travel times to decrease. ?? In general, significant volume and travel time reductions are seen on the entire western side of the study area as a result of the interconnected principal arterial system created in an area of expected population and employment growth. Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics Page 3-37 Table 3-11 Alternative Scenario 4 -Arterial Connections /Cross Regional Grid System Roadway Termini AADT % Change Travel Time % Change 19th Valley Center/Main -4.2 -2.58 I-90 East Belgrade Interchange/19th -10.17 -5.34 Alaska Alaska southern termini/I-90 218.68 4.08 Cameron Bridge Jackrabbit/Harper Puckett 84.79 2784.17 Cottonwood Kent Spur/Harper Puckett 39.98 -66.39 Durston Love/19th 17.47 8.59 Frontage East Belgrade Interchange/19th -19.38 -16.64 Gallatin Cottonwood/Jackrabbit -2.3 -14.07 Gooch Hill/Enders Cottonwood-Kent Spur/Love -10.76 -48.22 Harper Puckett Valley Center/Baxter 57.89 2843.66 Huffine Jackrabbit/Main -5.78 -20.35 Jackrabbit Huffine/I-90 -16.07 -6.98 Love Gooch Hill/Cameron Bridge 42.67 -97.78 Main Fowler/19th -6.34 -14.33 Oak Cottonwood/19th 92.87 -89.67 Valley Center Jackrabbit/19th -22.08 -39.37 Alternative Scenario 5 – Interstate 90 Overpass at Davis /Nelson Alignment The scenario is created to assess the benefits of providing a grade separated overpass of I-90 and the existing railroad tracks along the north-south alignment of Fowler/Davis and Nelson roads. This is not envisioned as an interchange; however it may serve to reduce traffic along the Frontage Road entering Bozeman, North 19th Avenue, and Valley Center Road. Scenario analysis results indicate: ?? Frontage Road entering Bozeman experiences a 7% decrease in AADT and 10% decrease in travel time. North 7th experiences a 3% decrease in AADT and 12% decrease in travel time. ?? North 19th and Valley Center both experience an increase in traffic volume and travel time, with North 19th seeing a 15% increase in AADT and 12% increase in travel time, and Valley Center experiencing an 18% increase in AADT and greater than 300% increase in travel time (from an average travel time of 3.3 minutes to 10.2 minutes). ?? Davis is impacted by a 76% increase in traffic volume, but a 67% decrease in travel time, indicating that the increased capacity is enough to accommodate the shift in traffic volume (volume/capacity ratio drops allowing travel times to decrease). ?? The intended goal to reduce traffic along the Frontage Road was addressed as a portion of trips are shifted from accessing Frontage Road at Springhill, to enter Bozeman. Instead, trips are shifted to the new capacity connection at Davis/Nelson Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Page 3-38 Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics to enter northeast Bozeman from Davis and North 19th. This shift in trips, however, causes the increase in traffic volume on these two facilities. Baxter also sees an increase in AADT of 15% and travel time of 56% as a result of a large number of trips shifting to the area. ?? Recommend testing additional improvements to Valley Center and/or North 19th if 1-90 Overpass is constructed at Davis/Nelson. Table 3-12 Alternative Scenario 5 -Interstate 90 Overpass at Davis /Nelson Alignment Roadway Termini AADT % Change Travel Time % Change North 19th Valley Center/Oak 15.09 11.84 7th Frontage/Oak -3.01 -12.03 Baxter Harper Puckett/7th 14.72 55.66 Davis Baxter/Nelson 76.47 -66.51 Frontage Sacajawea Peak/7th -7.39 -9.61 Hidden Valley Valley Center/Harper Puckett -10.8 -6.13 Oak New Holland/7th -1.18 -9.9 Valley Center Harper Puckett/19th 18.78 304.42 Alternative Scenario 6 – Interstate 90 Overpass at Baxter /Mandeville Alignment The scenario is created to assess the benefits of providing a grade separated overpass of Interstate 90 along the west-east alignment of Baxter/Mandeville Lane. This is not envisioned as an interchange; however it may serve to reduce traffic along the Frontage Road entering Bozeman, North 7th Avenue, and Griffin Drive. Scenario analysis results indicate: ?? North 7th experiences a 5% decrease in AADT, and a 19% decrease in travel time. ?? Frontage Road entering Bozeman benefits from a 5% decrease in AADT and 14% decrease in travel time. ?? Griffin experiences a 4% increase in AADT and 9% increase in travel time resulting from its proximity to the new capacity connection at Baxter/Mandeville, which causes additional trips to load onto Griffin heading to/from Baxter. For the same reason (proximity to new capacity connection), Mandeville sees a 233% increase in traffic volume, but a 56% decrease in travel time. Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics Page 3-39 Table 3-13 Alternative Scenario 6 -Interstate 90 Overpass at Baxter /Mandeville Alignment Roadway Termini AADT % Change Travel Time % Change 7th Oak/Frontage -5.43 -19.21 Baxter Davis/Mandeville 9.08 -2.14 Davis Baxter/Valley Center 0.51 2.27 Frontage Nelson/7th -5.13 -13.83 Griffin Mandeville/Rouse 4.27 8.51 Mandeville Baxter/Griffin 232.57 -55.7 Oak New Holland/Rouse 0.92 0.01 Rouse Oak/Griffin -3.84 -20.02 Alternative Scenario 7 – Southwest Grid Modifications The scenario will expand and strengthen the southwest grid in an existing and forecasted growth area. It includes the following: ?? College Street upgrade to a five-lane principal arterial between Main Street and S. 19th Ave. ?? College Street upgrade to a three-lane minor arterial between S. 8th Ave. and S. 19th Ave. ?? Extending Kagy Boulevard from S. 19th Avenue to Cottonwood near the Stucky Road intersection (as a three-lane principal arterial) ?? Completing the Fowler Lane connection from Garfield Street south to Stucky (as a minor arterial). Scenario analysis results indicate: ?? Parallel facilities to the new Kagy Boulevard capacity extension, Babcock and Stucky, show significant travel time benefits as trips shift to the new capacity; Babcock sees a 4% decrease in AADT and 10% decrease in travel time, Stucky sees a 62% decrease in AADT and almost 100% decrease in travel time. ?? Overall, Kagy experiences a 48% increase in AADT as a result of trips shifting to the upgraded and expanded facility, but only a slight 3% increase in travel time. ?? College Avenue between Cottonwood and 11th benefits from a 5% decrease in AADT and a 27% decrease in travel time. ?? Extension of Fowler lane from Stucky to Garfield Street is causing an increase in traffic volume on Fowler of 41% and a significant increase in travel time of 359%. While you would expect an increase in volume on on the facility as trips are shifted to the new capacity, the increase in travel time may not warrant the new capacity addition, in particular as the parallel facilities Cottonwood and 19th are not showing significant traffic improvements as trips are shifted from these facilities to the new capacity; Cottonwood shows a 4% increase in travel time and 19th shows a 5% increase in travel time. Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Page 3-40 Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics Table 3-14 Alternative Scenario 7 -Southwest Grid Modifications Roadway Termini AADT % Change Travel Time % Change 19th Babcock/Patterson -0.97 4.64 Babcock Cottonwood/11th -3.66 -10.1 College Cottonwood/11th -5.15 -27.42 Cottonwood Patterson/Babcock 0.17 3.73 Fowler Patterson/Babcock 40.98 359.43 Huffine Cottonwood/11th -2.24 -11.13 Kagy Cottonwood/7th 48.34 3.03 Stucky Cottonwood/19th -62.53 -98.5 Alternative Scenario 8 – Kagy Boulevard Expansion This scenario involves expanding the existing Kagy Boulevard from its current two-lane configuration (with left-turn bays) to a widened five-lane principal arterial. This would create a high capacity principal arterial corridor. Scenario analysis results indicate: ?? Kagy Boulevard benefits from a decrease in travel time of 4%, despite a slight increase in AADT of 1%, with the AADT increase expected due to the improvement of the facility. Adjacent Bozeman Trail also benefits from a 5% decrease in AADT and 2% decrease in travel time. ?? Other impacts in the area of improvement are minimal/negligible (see Table 3-15 below), with the most significant change occurring on Sourdough which shows a 16% decrease in AADT and 36% decrease in travel time. Table 3-15 Alternative Scenario 8 -Kagy Boulevard Expansion Roadway Termini AADT % Change Travel Time % Change 19th Goldenstein/Main 4.38 8.46 3rd Goldenstein/Westridge 0.09 -2.14 Babcock 19th/Church -0.63 1.43 Bozeman Trail Haggerty/Tayabeshockup -4.53 -1.56 Church Main/Sourdough -0.58 -1.15 Highland Bozeman Trail/Main -0.01 0 Kagy 19th/Tayabeshockup 1.07 -4.07 Main 19th/Haggerty 0.8 3.43 Sourdough Goldenstein/Church -16.06 -35.97 Willson Bozeman Trail/Main -1.13 -0.92 Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics Page 3-41 Alternative Scenario 9 – Fowler Lane Extension This scenario involves completing the Fowler Lane corridor north of Main Street, specifically between Babcock and Oak Street, in hopes of providing additional north-south travel mobility. This is envisioned as a minor arterial facility. Scenario analysis results indicate: ?? Fowler experiences a significant increase of 285% AADT due to the shift in trips to the newly upgraded north-south arterial facility, but a 72% decrease in travel time; indicating that the increase in additional capacity between Babcock and Oak is able to accommodate the shift in travel to the upgraded corridor (i.e., volume/capacity ratio is reduced allowing travel times to decrease). ?? Adjacent Davis Street, at the north end of Fowler, benefits from a 12% decrease in AADT and a 35% decrease in travel time. ?? ?? Parallel facility, Cottonwood, benefits from a 5% decrease in volume and 14% decrease in travel time, as trips are shifted to Fowler; however parallel 19th shows in a increase in volume and travel time of 6% and 8%, respectively. ?? Surrounding key facilities show largely improved travel conditions as indicated in Table 3-16 below. Table 3-16 Alternative Scenario 9 -Fowler Lane Extension Roadway Termini AADT % Change Travel Time % Change 19th Babcock/Valley Center 5.98 7.84 Babcock 19th/Cottonwood -0.98 -42.69 Cottonwood Huffine/Durston -4.57 -13.93 Davis Valley Center/Baxter -11.89 -34.71 Durston Cottonwood/19th 15.4 7.93 Fowler Huffine/Davis 284.7 -72.01 Huffine Cottonwood/Main -4.78 -18.73 Main Huffine/19th -8.4 -17.76 Oak Fowler/19th -12.54 -50.1 Valley Center Hidden Valley/19th -7.52 -14.78 Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Page 3-42 Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics Alternative Scenario 10 – Northwest Grid Modifications As with AS 1 – East Belgrade Interchange, the northwest grid system modification have been developed to address the growth occurring in the north-west portion of the study area. This scenario has been modeled to complete the principal arterial system in the “triangle” area. This model scenario includes the following: ?? All aspects of AS 1 -East Belgrade Interchange. ?? Extension of Oak Street from its current western terminus all the way to the west to intersect Love Lane (as a principal arterial). ?? Extension of Love Lane to the north to connect with Cameron Bridge Road, as a principal arterial. ?? Extension of Cottonwood Road from its current terminus to Valley Center Road (as a principal arterial). ?? Re-classification of Monforton School Road to a collector with attributes adjusted accordingly. ?? Extension of Hulbert Road from its eastern terminus to the east to connect with an extended Harper Puckett Road (as a collector). Scenario analysis results indicate: ?? Similar to AS 1, traffic is being pulled onto Alaska, Cameron Bridge, and Love Lane to access the new interchange. Each of these roadways experiences an increase in traffic volume with Alaska seeing a 217% increase, Cameron Bridge a 45% increase, and Love Lane a 25% increase in AADT. Note that despite the volume increase on Love, average travel time drops by almost 100% from 28 minutes to less than 1 minute. ?? Huffine experiences a 6% decrease in AADT and 21% decrease in travel time, and Valley Center shows a 30% decrease in AADT and 60% decrease in travel time. ?? Jackrabbit, between Huffine and Amsterdam, also shows travel benefits, with a 14% decrease in AADT and 6% decrease in travel time. ?? There is a significant shift in traffic from Hidden Valley Road (66% decrease in AADT and 13% decrease in travel time), a collector street, to Harper Puckett/Cottonwood, due to the Cottonwood extension as a higher functional class principal arterial. ?? Oak shows a 31% increase in volume, but a 120% decrease in travel time. This is a result of new capacity connections causing a shift in traffic volume to the upgraded facility. The volume increase is not enough, however, to exceed available (new) capacity allowing average travel times to decrease. Similarly, Harper Puckett shows an 11% increase in AADT, but a 41% decrease in travel time. ?? In general, grid modifications in connection with the new interchange appear to support reductions in traffic volume and travel times on key facilities in the north-west portion of the study area as traffic is dispersed on to a completed grid system to the south and west of the new interchange. Some locations (e.g., Cameron Bridge and the southern portion of Cottonwood at Huffine) are showing more localized, but fairly significant increases in travel time, however, and may require additional analysis. Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics Page 3-43 Table 3-17 Alternative Scenario 10 -Northwest Grid Modifications Roadway Termini AADT % Change Travel Time % Change Alaska Alaska southern termini/I-90 217.45 3.61 Baxter Jackrabbit/19th -23.88 54.62 Cameron Bridge Thorpe/Harper Puckett 44.9 1177.57 Cottonwood Huffine/Valley Center 47.34 583.19 Durston Love/19th 8.73 4.41 Harper Puckett Cameron Bridge/Hulbert 11 -41.47 Hidden Valley Valley Center/Hulbert -65.85 -12.63 Huffine Jackrabbit/Main -5.77 -21.13 Jackrabbit Huffine/Frank -13.99 -5.74 Love Huffine/Cameron Bridge 25.31 -97.94 Oak Love/19th 31.01 -119.59 Valley Center Jackrabbit/Harper Puckett -30.47 -60.35 Alternative Scenario 11 – Amsterdam On-Ramp This scenario added an interchange on-ramp from Amsterdam Road onto Interstate 90 to reduce congestion at Amsterdam Road and Jackrabbit Lane (just south of Belgrade). Scenario analysis results indicate: ?? A reduction in 25% AADT and 89% travel time on Amsterdam, and a reduction of 1.32% AADT and 1.89% travel time on Jackrabbit. ?? Impacts in the surrounding area are minimal. Reference Table 3-18 below. Table 3-18 Alternative Scenario 11 -Amsterdam On-Ramp Roadway Termini AADT % Change Travel Time % Change Alaska Cameron Bridge/I-90 -1.3 0 Amsterdam Jackrabbit/-25.01 -88.93 Cameron Bridge Thorpe/Alaska 0.58 6.43 Jackrabbit Hulbert/Amsterdam -1.32 -1.89 Frank Thorpe/Jackrabbit -1.26 -7.23 Thorpe Cameron Bridge/-3.99 -3.05 Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Page 3-44 Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics Alternative Scenario 12 – Southern Grid Modifications The southern grid modifications include the following: ?? Extend 11th Ave. from Kagy Boulevard to Goldenstein (as a collector). ?? Extend 15th Ave. from Main Street to Babcock (as a collector). ?? Extend Blackwood Road from S. 19th Ave. west to Cottonwood Road (as a minor arterial). Scenario analysis results indicate: ?? 11th Street AADT increases 16% with a slight 1.24% increase in travel time. 15th Street AADT increases by 111% with a 17% increase in travel time. These increases are a result of the new capacity connections causing a shift in trips and traffic volume to the expanded facilities, with most significant volume increases occurring on links immediately adjacent to new capacity. The fairly large travel time increase on 15th is likely because the capacity addition is very short in length; trips are shifted to the newly connected facility causing volume to increase, but the slight capacity addition is not enough to accommodate this increase, therefore volume/capacity ratio increases and travel time increases. ?? 19th and Wilson/3rd, both of which run parallel to the upgraded 11th and 15th street facilities, experience a reduction in AADT and travel time due to the shift in trips to 11th and 15th. ?? Cottonwood benefits from a significant decrease in AADT of 27% and travel time decrease of 54%, as new capacity connections on Blackwood and 11th create more direct access to downtown Bozeman. ?? Kagy Boulevard shows a 4% decrease in AADT and less than 1% decrease in travel time. ?? Patterson and Stucky, which run parallel to the Blackwood extension, see significant benefit due to the grid modifications in the area which allow traffic to more evenly disperse onto other facilities. Patterson shows a 14% decrease in AADT and 43% decrease in travel time and Stucky shows a 9% decrease in AADT and 48% decrease in travel time. ?? Sourdough benefits from a 25% decrease in AADT and 52% decrease in travel time. ?? In general, grid modifications appear to support reductions in traffic volume and travel times on key facilities in the southern portion of the study area as traffic is dispersed on to a completed grid system. Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics Page 3-45 Table 3-19 Alternative Scenario 12 -Southern Grid Modifications Roadway Termini AADT % Change Travel Time % Change 11th Goldenstein/Durston 15.93 1.24 15th College/Durston 111.53 16.95 19th Cottonwood/Durston -0.57 -1.82 3rd Goldenstein/Kagy -21.56 -4.96 College 19th/Willson -0.19 1.89 Cottonwood 19th/Stucky -26.95 -53.54 Durston 19th/Rouse -26.95 0.13 Goldenstein 19th/Sourdough -13.74 -18.02 Kagy 19th/Sourdough -4.07 -0.63 Patterson Cottonwood/19th -14.37 -42.88 Sourdough Goldenstein/Kagy -24.5 -51.94 Stucky Cottonwood/19th -8.7 -48.3 Willson Kagy/Peach -3.74 -2.2 Alternative Scenario 13 – Interstate 90 Interchange (Harper Puckett Road) The purpose of AS-13 is to model the effects of a future interchange approximately half way between the proposed East Belgrade interchange and the 19th Avenue interchange. This scenario includes includes all aspects of AS-1 as well. It should be noted that the Federal Highway Administration requires that new interstate access points must serve a regional purpose. At this time this scenario would not serve a regional need and as such would not meet Federal Highway Administration requirements. Scenario analysis results indicate: ?? Similar to AS 1 and AS 10, traffic is being pulled onto Alaska, Cameron Bridge, and Love Lane, to access the new East Belgrade interchange. Each of these roadways experiences an increase in traffic volume with Alaska seeing a 170% increase, Cameron Bridge a 103% increase, and Love Lane a 24% increase in AADT. Note that Cameron Bridge is seeing a much greater increase in AADT compared to Alternatives 1 and 10 because of the additional interchange directly to the north of the roadway, causing even more trips and traffic volume to shift to this facility. The very significant increase in travel time on Cameron Bridge resulting from this shift in traffic volume (average-weighted travel time increase greater than 4500%; or in absolute terms, an increase in average travel time from 9-87 minutes), may preclude this as an alternative to consider, unless additional improvements are made in the area. ?? Most roadways in the area are experiencing a general increase in AADT and travel time as a significant number of trips shift to access I-90 at one of the two proposed Greater Bozeman Area Transportation Plan (2007 Update) Chapter 3: Travel Demand Forecasting Page 3-46 Robert Peccia & Associates, Inc. /ALTA Planning + Design /Cambridge Systematics interchanges. I-90 does show improvement, with a 13% decrease in AADT and 32% decrease in travel time, as a result of some traffic shifting off of the interstate onto the arterial system to access the City of Bozeman. Jackrabbit also sees a decrease in 15% AADT and 6% travel time, similar to AS 1 and AS 10. ?? There is no apparent benefit to this scenario over Alternative 1 which includes only the East Belgrade Interchange (with the exception of greater travel benefits on I-90 in the area of improvement). This is possibly because the proposed interchanges are located too closely together, drawing too much traffic into the north west portion of the study area to access I-90 in the same general location. Table 3-20 Alternative Scenario 13 -Interstate 90 Interchange (Harper Puckett Road) Roadway Termini AADT % Change Travel Time % Change 19th Goldenstein/Main 4.38 8.46 3rd Goldenstein/Westridge 0.09 -2.14 Babcock 19th/Church -0.63 1.43 Bozeman Trail Haggerty/Tayabeshockup -4.53 -1.56 Church Main/Sourdough -0.58 -1.15 Highland Bozeman Trail/Main -0.01 0 Kagy 19th/Tayabeshockup 1.07 -4.07 Main 19th/Haggerty 0.8 3.43 Sourdough Goldenstein/Church -16.06 -35.97 Willson Bozeman Trail/Main -1.13 -0.92 3.10 TRAFFIC MODEL DEVELOPMENT CONCLUSIONS The alternative scenarios modeled, and described above, are reflective of major street network (MSN) projects that may or may not have considerable value to the transportation conditions in the community. Some of the alternative scenarios modeled will be carried forward later in the Plan in the form of specific recommendations. These are primarily found in Chapter 5. A few of the scenarios do not appear to have substantial value, so will not be considered further. Ultimately, the recommended projects defined in Chapter 5 will transform into what is known as the community’s “Recommended Major Street Network”. This network is shown graphically in Chapter 9, along with travel demand model volume outputs. The “Recommended Major Street Network” is the future transportation system network that the community should be planning towards as land use changes occur over the planning horizon (year 2030).