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Home My WebLink About01-12-18 Correspondence - Montana Department of Transportation (MDT) to TCC - Bozeman Interstate 90 Speed Study Montana Department of Transportation Butte District Office PO Box 3068 Butte, MT 59702-3068 zero deaths I zero serious injuries on Montana roadways January 12, 2018 Chris Scott, Chair Bozeman Area Transportation Coordinating Committee PO Box 1230 Bozeman, MT 59771 Subject: Speed Study - Bozeman Area of Interstate 90 Dear Chairman Scott, In your November 15, 2017 correspondence you requested that MDT look at the speed limit within the Bozeman Urban Area. Your request was submitted to our Traffic Operations Engineering Section and they found that a speed study on Interstate 90 from milepost 295.0 to milepost 319.1 had already been performed. The results of the speed study were summarized in the attached report dated September 22, 2016. The report was submitted to Bozeman, Belgrade and Gallatin, County to comment on the speed limit recommendations which stated that a 75-mph speed limit beginning at milepost 297.1 (west of Belgrade) and continuing east to milepost 319.1, an approximate distance of 22-miles was justified. Gallatin County commented that they were supportive of the 75-mph recommendation. Bozeman and Belgrade did not submit comments. The 75-mph speed limit was presented and approved by the Montana Transportation Commission in December of 2016. MDT staff specifically looked at the option of a 65- mph speed limit, but the engineering does not support it. With respect to stacking at the exit ramps during peak hours, our Traffic Operations staff completed timing projects on N7th and N19th. Queuing on the ramps was not identified as a concern. Through an AID grant project, N19th was looked at again and no issues on the ramps were identified. The EB off ramp at N19th is scheduled for signalization in 2019. Can you provide more specifics on where we are having issues, such as the location, what time of day, what time of year, etc. so that we can address your concerns? If you have any further questions, feel free to contact me at 494-9625. Sincerely, Jeffrey . E ert, P.E. vt Butte District Administrator Copies: Roy Peterson, PE —Traffic and Safety Bureau Danielle Bolan, PE —Traffic Operations File Montana Department of Transportation PO Box 201001 Helena, MT 59620-1001 zero deaths I zero serious injuries on Montana roadways Memorandum To: Jeff Ebert, P.E. - Butte District Administrator From: Danielle C. Bolan, P.E. -Traffic Operations Engineer Date: September 22, 2016 Subject: Speed Limit Investigation Interstate 90 - W. Belgrade - Bear Canyon Please present the following information to the appropriate local contacts for Belgrade, Bozeman and Gallatin County for review and comment. All comments received will be reviewed and carried forward to the Montana Transportation Commission. In the event that local governing bodies do not comment we will proceed forward in presenting the following report to the Montana Transportation Commission at the December 15, 2016 meeting in Helena. Senate Bill 375 (SB 375) approved legislation revising the maximum speed limit on Montana's Interstate System to 80 mph. It included language authorizing the Transportation Commission to establish temporary speed limits. The Commission set temporary speed limits of 75 mph on Interstate segments that staff reasonably believed may not have been suitable for the 80 mph speed limit established in 61-8-303(1)(a) without the documentation of an engineering and traffic investigation. Based on our previous experiences in other highly populated areas, the close proximity of Belgrade and Bozeman to one another and the adjacent "Bear Canyon" segment having geometric constraints the 75 mph speed limit remained in effect on an interim basis pending and engineering and traffic investigation. It was our belief that the highly developed-congested area and the "Bear Canyon" segment are operating below the level in which the 80 mph speed limit is intended. Vehicular travel speeds were sampled directionally at numerous locations throughout the study segment. Those speed statistics were merged with the Interchange Locations and the 2014 traffic volume data by milepost. Interstate 90 -W. Belgrade to MP 319.1 1 of 2 Date AADT MP 294.8-BEGIN 75 MPH MP 295.0#1a EB WB 4-Apr-16 All 14230 #of veh 1618 1556 Com. 2286 85th% 81 mph 79 mph PACE(% 72-82(59%) 70-80 48% MP 297.0#2m EB WB 6-Apr-16 All 14230 #of veh 1840 1873 Com. 2286 85th% 79 mph 80 mph PACE(%) 64-74(50%) 70-80 59Yo MP 298.3-BELGRADE INT MP 299#3a EB WB 6-A r-16 All 19050 #of veh 1930 2040 Com. 2257 85th% 75 mph 75 mph PACE %) 6474 62% 64-74 62% _ � _MP 299.5-E. BELGRADE INT MP 301.0#4m EB WB 7-A r-16 All 19050 #of veh 3079 2992 Com. 2257 85th% 77 Mph 78 mph PACE(%) 68-78(67%) 69-79(65%) MP 303.0#5m EB WB 7-A r-16 All 19050 #of veh 2930 1771 Com. 2257 85th% 78 mph 76 mph PACE(%) 69-79(59%) 65-75 67% N � MP 305.0#6a EB WB 11-Mar-16 _ #of veh 2258 3248 MP 305.2-N 19th AVE INT 85th% 77 mph 76 mph All 17940 PACE(%) 67-77(60%) 49-59 35% Com. 2257 j ti MP 306.9#7m EB WB 11-Apr-16 All 14820J MP 306.9-W BOZEMAN INT #of veh 1591 1716 Com. 2097 85th% 77 mph 77 mph PACE(%) 65-75(63%) (67-77)64% MP 309.0#8r EB WB 6-Apr-16 #of veh 128 130 MP 309.4-E BOZEMAN INT 85th% 78 mph 75 mph All 15330 PACE(%) 68-78(72%) 65-75(69%) Com. 2178 MP 311.0#9r EB WB 4-Apr-16 All 15330 '#of veh 137 139 Com. 2178 85th% 80 mph 77 mph PACE(%) 71-81(77%) 68-78(71% MP 313.2#10r EB WB 4-Apr-16 All 15330 #of veh 131 126 Com. 2178 MP 313.5-BEAR CANYON INT �85th% 79 mph 80 mph PACE(%) 71-81 9Yo 68-78(69%) MP 314.7 65 mph 65 mph ADVISORY MP 315.0#11r EB WB 6-Apr-16 All 15330 #of veh 127 124 Com. 2178 85th% 78 Mph 77 mph PACE(%) 68-78 68Yo 68-78(64%) MP 315.3 65 mph 65 mph ADVISORY MP 316.0#12r EB WB 6-Apr-16 All 15330 #of veh 128 133 Com. 2178 85th% 78 mph 77 mph PACE(%) 71-81(71%) 68-78(68%) MP 316.7- TRAIL CR INT Interstate 90 -W. Belgrade to M P 319.1 2 of 2 Date AADT MP 317.3#13a EB WB 11-Apr-16 All 13540 #of veh 1965 2273 Com. 2178 85th% 75 mph 73 mph PACE(%) 64-74(55%) 61-71(63%) MP 317.5 60 mph 60 mph ADVISORY MP 318.0#14r EB WB 7-Apr-16 All 13540 #of veh 136 127 Com. 2178 85th% 76 mph 80 mph PACE(%) 68-78(63%) 71-81(67%) MP 319.0#15r EB WB 7-Apr-16 All 13540 #of veh 127 132 Com. 2178 85th% 79 mph 78 mph PACE(%) 71-81(70%) 68-78(65%) ✓ MP 319.1-BEGIN 80 MPH Separate from the traffic operational data, Crash and Citation data statistics were retrieved and summarized by category and distribution with the study area. Each was reviewed for a three-year period from June, 1, 2012 to May 31, 2015. Citation Data Citations 1-90 Belgrade - MP 319.1 1/1/13-12/31/15 2% 696 ■Seat Belt Violations 17% ■Speed Limit Violations 45% Lic.&Ins.Violations 18% ■Operating-Careless Violations 12% 18% ■DUI&Criminal Violations 6% Other Violations 2% 21153 Traffic Stops Resulting In 2,493 Citations Issued Citation Histogram ■Citations 250 — — -- -- I 200 - — — A to C 150 - — — — - L - _1TIT- , 1 50 — — — - p N N N W W W W W W W W W W g NN iR m o0 o ro Milepost Crash History Crashes 1-90 Belgrade - MP 319.1 1/1/13- 12/31/15 12`Yo ■Fixed Object 32% ■Rollover 13% Rearend 19% ■Sideswipe SD 7% ■Animal 17% Other SV& MV 12% 541 Reported Crashes 19% Crash Histogram ■# of Crashes 90 TITITIJ 80 70 60 c 0 = 50 a� 'L 40 M 30 — — 20 10 0 - N �N�ppN�pp pW W W pWp pWp W W W W W 01 00 O N T 00 O 00 00 N Milepost Conclusions and Recommendations Our review of the travel speeds indicates traffic is operating more within the 75 mph and below range for the vast majority of the study area. There are some variations above 75 mph, but they are not necessarily representative of the entire segment as a whole. However, on either end of the study area voluntary compliance in the 75 mph speed limit starts to decline, as does the number of reported crashes. Under the present traffic volume and interchange spacing the Bozeman-Belgrade area is not experiencing the type of operation that would support a 65 mph speed limit, as observed in other urban areas. The crash histogram shows a definite spike in the number of crashes occurring in the Belgrade area. This information pre-dates the completion of the East Belgrade Interchange and is not reflective of today's conditions. The addition of the interchange and the additional travel lanes should provide relief in the level of conflict within this spot specific area. The following recommendation perpetuates the majority of the 75 mph interim speed limit. However, we have opted to move the western boundaries of the zone inward to better coincide with the actual travel speeds. A 75 mph speed limit beginning at milepost 297.1 (west of Belgrade) and continuing east to milepost 319.1, an approximate distance of 22-miles. DCB:DRB:TRF:I-90-belgrade-bearcanyon_rpt copies: Roy Peterson, P.E. -Traffic and Safety Bureau Jennifer Nelson, P.E. - Butte District Lee Alt, - Butte District Doug Bailey-Traffic Operations Section File