HomeMy WebLinkAbout03-30-25 Public Comment - Rick Nys, Greenlight Engineering - Appeal 25033From:Rick Nys
To:Bozeman Public Comment
Subject:[EXTERNAL][SENDER UNVERIFIED]Appeal 25033
Date:Sunday, March 30, 2025 11:59:50 AM
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Guthrie TIS Review Greenlight 3-30-25.pdf
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Please include the attached comments in the referenced land use file.
Thanks,
Rick Nys, P.E.
Principal Traffic Engineer
Greenlight Engineering
503-317-4559
www.greenlightengineering.com
March 30, 2025
Bozeman City Commission
121 N Rouse Ave
Bozeman, MT 59715
RE: Appeal of Administrative Approval for Application 24493 – The Guthrie
Greenlight Engineering has been asked by Bozeman Home Advocacy Group, LLC to evaluate the transportation
related impacts of the proposed “The Guthrie” development in Bozeman, Montana. I have reviewed the
September 2024 “The Guthrie Traffic Impact Study” (“TIS”) and the March 26, 2025 staff report
I reviewed the transportation impacts of the previous application on this site and provided comments dated July
7, 2024 which are Exhibit 016 of this appeal.
Level of Service of 7 th Avenue/Beall Street and 7 th Avenue/Villard Street
The City's staff report states:
“Level of Service is a qualitative metric used to describe intersection operations as measured by average
vehicle delay. This is explicitly and inarguably not a direct measure of safety and does not even attempt to
evaluate modes of transportation such as bicycles and pedestrians. Further, there is no explicit industry
standard that can be applied to “prove” an intersection will operate safely nor any objective definition of
“safety”as a measurable metric. Adequate safety is presumed to derive from an intersection meeting
standards for appropriate geometry and traffic control, which both intersections of Villard and Beall with
North 7th Avenue comply in the existing and design year. Staff notes that higher level of service may in
fact require design features that allow for increased throughput and therefore reduced vehicle delay. Such
features include wider multi-lane intersections that increase pedestrian crossing distances and conflicts
with vehicles, prohibition of protected pedestrian phasing at signalized intersections, and permissive left
turn phasing instead of protected left turn phasing. Modern engineering practice has thoroughly
concluded such design features correlate with reduced, not improved, multimodal safety.”
The Highway Capacity Manual (HCM) provides a methodology for measuring the level of service (LOS) for
pedestrians. While there is no indisputable correlation between LOS and safety, the City of Bozeman’s adoption
of a whole-intersection LOS approach for a two-way stop-controlled intersection is unprecedented, a construct of
the City without any definition, and not industry standard. The City's whole intersection methodology has been
applied inconsistently across different applications over the years. Notably, the City does not use this whole-
intersection approach when planning its own projects, instead adhering to HCM methodology in the Bozeman
Transportation Plan.
Under the City’s whole intersection methodology, increasing traffic volumes on 7th Avenue would lead to
increasing delays for traffic on Beall Street and Villard Street, yet paradoxically, the reported LOS for the
intersection would often improve due the averaging of delays. Large volume 7th Street traffic essentially
experiences no delay while lower volume side street traffic experiences high delays. This counter intuitive result
raises potential safety concerns, as drivers attempting to enter 7th Avenue would face increasing delays and be
forced to accept smaller gaps in traffic. The HCM, which defines LOS, explicitly states that there is no
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methodology for evaluating two-way stop-controlled intersections as a whole, yet the City attempts to rely on a
non-existent methodology.
The staff report states:
“The Highway Capacity Manual states that failure of individual legs of a two-way stop controlled
intersection should not be the sole basis for selection of appropriate traffic control, which in this case
would be the required mitigation element. For this reason, and based on the requirement in
38.220.060.A.11.g.(2).(d). (“For two-way stop controlled intersections, analysis of whether the
intersection would satisfy signalization warrants if the two-way stop control was removed.”), staff
required a signal warrant study to determine the appropriateness of traffic control. The Developer
complied with this requirement as demonstrated by the Traffic Signal Warrant analysis dated October 11,
2024. The warrant studies determined signalization is not warranted and therefore, that form of
mitigation of the individual leg LOS failures through signalization was not required.”
While the most recent TIS studied the need for traffic signals at the 7th Avenue/Beall Street and 7th
Avenue/Villard Street intersections and found that traffic signal warrants are not met, that does not absolve the
application from also complying with the requirement of BMC Section 38.400.060(B)(4) which states:
“The city determines level of service (LOS) values by using the methods defined by the most recent
edition of the Highway Capacity Manual. The review authority may approve a development only if the
LOS requirements are met in the design year, which must be a minimum of 15 years following the
development application review or construction of mitigation measures if mitigation measures are
required to maintain LOS. Intersections must have a minimum acceptable LOS of "C" for the intersection
as a whole.”
In this particular application, the City attempts to rely upon a non-existent and undefined whole intersection
methodology while also dictating compliance with the Highway Capacity Manual. An applicant cannot meet
both requirements because those requirements directly conflict with each other. Meanwhile, the City utilizes
the actual HCM methodology as part of the Bozeman Transportation Plan. Presumably, the City is attempting to
rely upon the LOS C delay thresholds of the HCM for two-way stop controlled intersections even though the
HCM provides no definition of how to analyze an intersection in such a way nor does it present a way to
measure the performance of an intersection in that way because the LOS thresholds are based on those
movements that experience delay. The methodology, still undefined, appears to be an invention of the City and
surely not compliant with the HCM.
The staff report notes:
“Staff considered other potential mitigation solutions for individual leg LOS failures that would generally
restrict crossing and left turning movements from the local streets, Villard and Beall, onto North 7th
Avenue. Staff ultimately did not recommend mitigation for three reasons. First, the practical impact of
the reduction in minor leg LOS in the design year (2038) is 1 to 3 vehicles queued in the 95th percentile
scenario in the peak hour. The existing peak hour 95th percentile queue is 1. Therefore, the increase in
queued vehicles is small and occurs only during short durations of the day, which suggests the mitigation
measure would be of minimal benefit. Second, staff cannot find any evidence of public complaint or
dissatisfaction at these intersections that would indicate queuing of this nature is unacceptable. Finally,
the additional queuing and delay is almost entirely due to projected background growth in traffic volume
and not that which is induced by The Guthrie development itself. As a means of comparison, a traffic
study of the previous use of the site as an assisted living facility of lesser intensity in the design year
(2038) would have a high probability of showing a similar increase in queuing and decrease in minor leg
LOS.”
While staff presents this analysis, staff does not provide reference to any applicable code that indicates that this
analysis is relevant to the approval criteria. Approval of the application must be based on the approval criteria.
City staff notes:
“Appellant also finds fault with the City’s analysis of the LOS of intersections near The Guthrie because
the analysis was different from and inconsistent with an unrelated zone map amendment application for
a different location that was denied in 2022. The two applications are entirely distinguishable and denial
of the zone map amendment application near the intersection of Haggerty Lane and East Main Street has
no bearing or relation to staff’s analysis of The Guthrie site plan application. One critical distinction is
that the intersection of Haggerty Lane and East Main Street was evaluated in the 2017 Transportation
Master Plan and found to fail LOS while meeting conditions that warrant a signalized intersection. One
critical distinction is that the intersection of Haggerty Lane and East Main Street was evaluated in the
2017Transportation Master Plan and found to fail LOS while meeting conditions that warrant a signalized
intersection. In contrast, the intersections of Villard and Beall with North 7th Avenue do not meet signal
warrants...2024 Montana Department of Transportation traffic volume data indicates that traffic on
Haggerty Lane approaching East Main Street has an average annual daily traffic count of 2,986, which is
more than triple the traffic volume found on Beall and Villard. The combination of these factors indicates
a substantial difference in the conditions and analysis applied between the two projects. Appellant’s
proffered example is inapposite to the application at issue in this appeal.”
It is unclear how the applications are entirely distinguishable. The Haggerty application and City's decision
relied upon the applicant's HCM based methodology and not on the undefined, intersection as a whole
methodology that is not based on the HCM. The City, without explanation, has apparently taken opposite
approaches in interpretation of their standards with the Haggerty application and this application. This would
seemingly present a significant concern to City decision makers. It is certainly possible that when making
opposite interpretations of the same standard that opposite results such as approval or denial may occur. At the
very least, this example highlights the disparity in application of analysis methodologies and the lack of
compliance with the City's own Transportation Plan methodology.
Whether a traffic signal is warranted or not or how much side street volume is present is completely irrelevant
to the approval criteria. If the approval criteria is not met, then the application cannot be approved.
In my July 7, 2024 report, I noted:
“BMC Section 38.400.060(B)(4) states that 'The city determines level of service (LOS) values by using the
methods defined by the most recent edition of the Highway Capacity Manual.'
The Highway Capacity Manual states:
'LOS for a [two-way stop controlled] intersection is determined by the computed or measured
control delay. For motor vehicles, LOS is determined for each minor-street movement (or shared
movement), as well as the major-street left turns, by using the criteria given in Exhibit 20-2. LOS
is not defined for the intersection as a whole (emphasis added) or for major-street approaches
for three primary reasons: (a) major-street through vehicles are assumed to experience zero
delay; (b) the disproportionate number of major-street through vehicles at a typical TWSC
intersection skews the weighted average of all movements, resulting in a very low overall
average delay for all vehicles; and (c) the resulting low delay can mask LOS deficiencies for minor
movements...Unsignalized intersections are also associated with more uncertainty for users, as
delays are less predictable than they are at signals.'
The Highway Capacity Manual provides no methodology for analyzing level of service as a whole for two
way stop controlled intersections like N 7th Avenue/W Villard Street and N 7th Avenue/W Beall Street and
then explains why no such methodology exists. The N 7th Avenue northbound and southbound through
traffic have no delay as there is no traffic control (stop signs or signalization) to cause delay. With
increasing traffic on N 7th Avenue, the intersection, if considered as a whole, could theoretically improve
operations while in reality, side street traffic could be experiencing very long delays and difficulty turning
onto the N 7th Avenue. It doesn't make sense to analyze two way stop controlled intersections as a whole
as it may for an all-way stop controlled intersection or a signalized intersection. Indeed, the city's
adopted methodology clearly does not allow for analyzing an intersection in the way the city is
attempting to analyze intersections.”
BMC Section 38.400.060(B)(4) requires the use of “the methods defined by the most recent edition of the
Highway Capacity Manual.” If an analysis is not conducted using HCM methodology, then compliance with BMC
Section 38.400.060(B)(4) is not possible.
In my 25 years of preparing and reviewing traffic impact studies, I have never encountered any other agency
that assesses LOS for a two-way stop-controlled intersection based on delay for the entire intersection.
However, it is commonplace for agencies to adopt and apply standards based on the HCM, which the City has
simultaneously done and also currently employs as part of their Transportation Plan.
The HCM defines LOS for two-way stop-controlled intersections based on delay per vehicle for individual
movements or approaches that experience delay (not major street through movements), not for the
intersection as a whole. The HCM explicitly states “The LOS criteria apply to each lane on a given approach and
to each approach on the minor street. LOS is not calculated for major-street approaches or for the intersection
as a whole”.
In applying HCM methodology and the BMC’s requirement to analyze intersections using the HCM, along with
the results of the Traffic Impact Study (TIS), both of the N 7th Avenue/Villard Street and N 7th Avenue/Beall
Street intersections are projected to operate at LOS F.
As previously established, no methodology exists within the HCM to evaluate two-way stop-controlled
intersections as a whole. There is no technical definition for such a method, nor is there any adopted means of
measuring or calculating it. This methodology is not supported by any commercially available traffic engineering
software. The applicant’s TIS provides no evidence that illustrates how it was concluded that the N 7th
Avenue/Villard Street and N 7th Avenue/Beall Street intersections operate at LOS A. There is no HCM-based
methodology that could produce this conclusion, nor does the TIS include any supporting calculations that
support a finding of LOS A.
The TIS states that the projected average delay at the N 7th Avenue/Villard Street and N 7th Avenue/Beall Street
intersections is 3 and 2.5 seconds per vehicle, respectively. Meanwhile, the side street LOS (per HCM
methodology) is nearly 96 seconds at both intersections with individual movements experiencing a delay of up
to 175 seconds per vehicle. Although the HCM does not define LOS for a two-way stop-controlled intersection
as a whole, it can be inferred that the City is attempting to apply the HCM’s LOS thresholds based on delay of
movements and approaches that experience delay to the entire intersection even though the majority of traffic
at the intersections experience no delay.
Erroneously using those thresholds, an average delay of more than 25 seconds per vehicle would be required to
reach LOS C, or an increased delay of more than ten (10) times of the projected 2.5 seconds per vehicle.
However, given that through traffic on N 7th Avenue—comprising the vast majority of vehicles—experiences no
delay, the City’s methodology inherently skews the results. This flawed approach would commonly result in
traffic analysis that illustrates that as N 7th Avenue traffic volumes increase, the intersection’s overall LOS
improves, even as side street delays significantly worsen.
By this logic, delays on the side streets would have to vastly exceed 96 seconds per vehicle (likely minutes of
delay) to approach LOS C for the intersection as a whole. This methodology is fundamentally unsound, unheard
of, and does not align with the HCM, Bozeman's Transportation Plan or standard traffic engineering principles.
Excerpt of TIS
While city staff have testified that the LOS requirements of the BMC have remained unchanged for many years.
The Haggerty application, at minimum, establishes an inconsistent application of the same standard that could
result in opposite findings of LOS A vs. LOS F and approval vs. denial. It seems plausible that the City of
Bozeman has required improvements or denied projects based on the HCM/Transportation Plan methodology,
rather than evaluating projects under the whole intersection methodology. The variation in the city's
application of the BMC raises important questions about why opposite interpretations of the same standard
have been applied to different cases.
Notably, the City of Bozeman’s Transportation Plan is explicitly based on the HCM methodology, which directly
contradicts staff’s current interpretation of the BMC. Montana law requires consistency between transportation
plans and development codes. Montana Code Annotated § 76-2-304 states: “Zoning regulations must be...made
in accordance with a growth policy.”
Furthermore, BMC Section 38.100.050 requires that when conflicts arise between regulations, the most
restrictive standard must prevail. Additionally, BMC Section 38.110.010 formally adopts by reference the
Transportation Plan. Given that the HCM methodology results in a LOS F for this application, whereas the BMC’s
whole intersection approach interestingly yields exactly the opposite outcome, or LOS A, the HCM and
Transportation Plan methodology is demonstrably more restrictive and should arguably govern.
The “Existing and Projected Conditions Technical Memorandum,” an appendix of the Bozeman Transportation
Master Plan states:
“LOS for two-way stop (TWS) controlled intersections are based on the delay experienced by each
movement individually within the intersections, rather than on the average stopped delay per vehicle at
the intersection. This difference from the method used for signalized intersections is necessary since the
operating characteristics of stop-controlled intersection (sic) are substantially different. Driver
expectation and perceptions are entirely different. For two-way stop-controlled intersections, the
through traffic on the major (uncontrolled) street experiences no delay at the intersection. Conversely,
vehicles turning left from the minor street experience more delay than other movements and at time
(sic) experience significant delay. Vehicles on the minor street which are turning right or going across the
major street experience less delay than those turning left from the same approach. Due to this situation,
the LOS is based on the average delay incurred at the worst performing movement.
For all-way stop (AWS) and roundabout controlled intersections, LOS is based on average vehicle delay
experienced at the intersection. This methodology is similar to that of signalized intersections...”
The planned projects within the Transportation Plan, some of which are no doubt based on LOS standards, are
presumably based on the HCM methodology outlined within the plan itself. However, it is unclear whether the
City of Bozeman intended to apply one standard for evaluating its own projects and an entirely different
standard for assessing development projects. The approach in the Haggerty application vs. this application are
certainly inconsistent.
Applying the whole intersection methodology would yield significantly different results than using the
Transportation Plan/HCM methodology with one resulting in LOS A and the other resulting in opposite results
at LOS F. Given the clear discrepancy between these two approaches and the absence of any HCM methodology
supporting the BMC standard, it is possible that the BMC contains a significant and consequential error as
other intersection types besides two-way stop-controlled intersections include a HCM methodology to analyze
an intersection as a whole.
Mitigation for Substandard LOS
In considering mitigation for the “substandard LOS on the east and west legs” of the 7th Avenue/Villard Street
and 7th Avenue/Beall Street intersections, the TIS notes:
“The intersections of North 7th Avenue/West Villard Street and North 7th Avenue/West Beall Street are
anticipated to operate at substandard LOS on the east and west legs (local streets) during the AM and
PM peak hours. The addition of a dedicated left-turn lane on West Villard Street and right and left-turn
lanes on West Beall Street are not expected to result in a significant capacity improvement. The
installation of a two-way left-turn lane (TWLTL) on North 7th Avenue would have a larger improvement in
delay by permitting two-staged left-turns from the minor legs. This would require major reconstruction
to North 7th Avenue and is not an easily feasible solution. It is likely that when volumes are high on
North 7th Avenue during the AM and PM peak hours, vehicles attempting to make a left-turn from the
minor legs will reroute to a signalized intersection if excessive delay is experienced. Restrictions to West
Villard Street and West Beall Street minor legs could also be considered in the future to improve minor
leg operations; however, this change would greatly impact the connectivity of the neighborhoods. Minor
leg volumes at both deficient intersections are low and would not warrant the installation of a signal
unless a safety concern arises in the future...”
The BMC states that an exception to the LOS requirement may be granted “If an intersection within the area
required to be studied by section 38.220.060.A.12 does not meet LOS 'C' and the intersection has been fully
constructed to its maximum lane and turning movement capacity, then an LOS of less than 'C' is acceptable.”
However, this is not the case. It is clear based on the TIS that a TWLTL would likely be expensive, but the
expense of an improvement doesn't absolve the applicant of complying with the approval criteria. Just to the
north of these intersections, 7th Avenue has been constructed with a five lane section, so it is clear that the
corridor is not constructed to its maximum capacity. The TIS mentions, but doesn't evaluate any other options
that may mitigate this substandard LOS. There is no evidence that other exceptions have been evaluated or
granted. Any of these solutions could be implemented and may improve operations, but the TIS has not
analyzed any of them.
Traffic Calming
The staff report notes my July 7, 2024 “analysis finds fault in failure to adequately define the need for traffic
calming, which was required by staff through a condition of approval of the site plan. Traffic calming features
inherently support safety through reduction of vehicle speed. The independent report’s criticism of the City’s
failure to justify need for the traffic calming infrastructure contradicts its own claim that the development will
induce unsafe traffic operations.”
Staff has incorrectly interpreted my comments. My traffic calming comments also do not pertain to my
concerns about the 7th Avenue/Beall and 7th Avenue/Villard intersections. My report notes:
“The TIS addendum #2 insinuates that whether a street has a traffic volume over 1,000 vehicles per day
is the major determining factor in determining the need for traffic calming and that if a street has a
traffic volume under 1,000 ADT, traffic calming measures should not be considered. Rather, the FHWA
ePrimer notes that “For example, a jurisdiction could have a minimum daily traffic volume (e.g., 1,000
vehicles per day; 100 vehicles during peak hour in one direction) before consideration is given to
implementing traffic calming.” The ePrimer provides an example of a possible threshold, but does not
suggest or dictate this threshold....Notably, the TIS, TIS addendum and TIS addendum #2 don't provide
any evidence of the traffic counts or traffic speeds collected in reviewing the need for traffic calming in
the neighborhood.”
The ePrimer referenced by the applicant's TIS refer to numerous other considerations for the need for traffic
calming. My comments are not an argument against traffic calming, but questions whether adequate traffic
calming has been proposed. The TIS appears to rely solely upon a volume threshold that the City has not
adopted, but there is other relevant criteria as to when traffic calming should be considered.
Should you have any questions, feel free to contact me at 503-317-4559.
Sincerely,
Rick Nys, P.E.
Principal Traffic Engineer