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HomeMy WebLinkAboutSILVER OAKS - PRELIMINARY - 14-88F - SUBMITTAL DOCUMENTS - ROUND 1 - TRAFFIC STUDY0 0 HORSETOOTH WEST SITE ACCESS STUDY FORT COLLINS, COLORADO AUGUST 1992 Prepared for: Tri Trend Homes 1505 Timberline Road Fort Collins, CO 80524 Prepared by: MATTHEW J. DELICH, P.E. 3413 Banyan Avenue Loveland, CO 80538 Phone: 303-669-2061 EXECUTIVE SUMMARY . Horsetooth West is a proposed commercial and residential development located near the intersection of Taft Hill Road and Horsetooth Road. This traffic impact study involved the steps of trip generation, trip distribution, trip assignment, capacity analysis, traffic signal warrant analysis, signal progression analysis, and accident analysis. This study assessed the impacts of Horsetooth West on the short range (1995) and long range (2010) street system in the vicinity of the proposed development. As a result of this analysis, the following is concluded: - The development of Horsetooth West is feasible from a traffic engineering standpoint. At full development as proposed, approximately 6100 trip ends will be generated at this site daily. - The Taft Hill/Horsetooth intersection currently operates acceptably with signal control and the existing geometrics. The Taft Hill/Bronson intersection operates acceptably considering the recent delay criteria research. - By 1995, given development of the residential portion of Horsetooth West and an increase in background traffic, the signalized intersection of Taft Hill/Horsetooth will operate acceptably. The existing geometrics will be adequate at the Taft Hill/Horsetooth intersection. The stop sign controlled intersections will operate acceptably. - By 2010, the Taft Hill/Horsetooth intersection will operate acceptably in the morning and afternoon peak hours with a typical four lane cross section with left -turn lanes on each leg. The stop sign controlled intersections will operate acceptably. - In the long range future (2010), the proposed stop sign controlled right-in/right-out access to Taft Hill will operate acceptably. A right -turn deceleration auxiliary lane is warranted. This right -turn lane would remove vehicles from the through traffic stream on Taft Hill, providing a safer condition. This right -turn lane should be at least 240 feet long including taper and assuming a 15 mph turn radius. - With the recommended control and geometrics, the accident rate should be at an acceptable level for typical urban conditions. 0 0 I. INTRODUCTION This traffic impact study addresses the capacity, geometric, and control requirements at and near a proposed development known hereinafter as Horsetooth West. It is located near the intersection of Taft Hill Road and Horsetooth Road in Fort Collins, Colorado. During the course of the analysis, numerous contacts were made with the project planning consultant (Gefroh Hattman, Inc.), the project engineering consultant (Stewart & Associates), and the Fort Collins Traffic Engineering Department. This study generally conforms to the format set forth in typical traffic impact study guidelines. The study involved the following steps: C _ Collect physical traffic and development data; Perform trip generation, trip distribution, and trip assignment, - Determine peak hour traffic volumes and daily traffic volumes; - Conduct capacity and operational level of service analyses on key intersections; - Analyze signal warrants and signal progression; - Analyze potential changes in accidents and safety considerations. II. EXISTING CONDITIONS The location of Horsetooth West is shown in Figure 1. It is important that a thorough understanding of the existing conditions be presented. Land Use Land uses in the area are primarily vacant or residential. Residential development exists to the east, across Taft Hill Road, and to the south of Horsetooth West. A small parcel of vacant land exists to the southeast across the Taft Hill/Horsetooth I intersection. To the west of the site, land is vacant. Land to the north of this site is large lot residential. Land in the area is essentially flat. Beginning at approximately Horsetooth Road, Taft Hill Road climbs a small grade to the south. This small grade has little effect on traffic operations and no effect on sight distance. The center of Fort Collins lies to: the northeast of Horsetooth West. Roads in Figure The primary streets near Horsetooth West are shown 2. Taft Hill Road is east of Horsetooth West. It is a north -south 1 I Gravel Vk Pits 2 3 '4 Christma Field t CQ 60 _AJ 01 JL: U A. rI,F.Iwe I �2, 6 0 19 :j JT1 _B11 I�Lj -11 .111111 Q) A c ml, -, P., I F! 0EIL101aiJI IM JOIL Golf -1-JUILAU-11- Course 11101 E - - =7* ....... 10-f f11P _RQ yfl� LLI W - L 17 T Fi`j Ila 1 kklk tt U!41VER IT z 7.� —, p I V sou 5 IS44 �T A\ � 4 Hughes /& - Stadium e< :/' -'--��22 "'lye 20 Hit 23# 4 - q !TheaDrive- 4, ler" Daml , ,�� (_ % �a It rakes a l% x ,,5 S U:b .la 611 11 North Yai sugar Refind y 7. Ea JCS -,--,Po S we /510 BM 4954 ICJr `Rospfrlli,�zi 1�,Z, L43 11� L j= UL Vy ic- -.ir t F—lif jV2�L .1VI 2 6 0 28 :[r .7 U;l r F; Pill X, r Mor Ill omelp f 579 HORSETOOT ROAD 1082 r765 Pll� r Ho'' 6 't h' St Dry 36 9 A 91 51, .1,ak 34 35 Spring Canyoni`z - I . . "Gravel Dam Me Clellands Pit Harmon\ Ceml V T _ it �sold 4) ------- t � -- -:__., Z9 f,5000 4. 2T, .11 SITE LOCATION Figure 1 N 0 Q 0 LL Q SITE Loo '•- BRONSON w SITE z Existing O Olander School w p z r-.. ..� Q • SITE HORSETOOTH ROAD 11 PRIMARY STREETS Figure 2 street designated as an arterial on the Fort Collins Master Street Plan. In this area, it has a two lane cross section, with right - and -left -turn lanes at the Taft Hill/Horsetooth intersection. The curb locations are established for an eventual four lane urban cross section adjacent to the site. The posted speed limit is 35 mph. Sight distance is generally not a problem along Taft Hill Road. The Taft Hill/Horsetooth intersection is signalized. The nearest other signal along Taft Hill Road is at Drake to the north. No signals exist south of this site. Horsetooth Road is south of this site. It is an east -west street designated as an arterial on the Fort Collins Master Street Plan. Adjacent to the site, Horsetooth Road is improved to its future four lane width, but it is striped as a two lane street both east and west of Taft Hill Road. The excess width is used for turning lanes approaching the Taft Hill/Horsetooth intersection. Horsetooth Road is posted at 35 mph. The nearest signalized intersection along Horsetooth Road is at Shields Street to the east. No signals exist west of this site. Existing Traffic Peak hour traffic is shown in Figure 3. These counts were obtained in July 1992. Due to the time of year, Olander Elementary School trips are not included in these counts. Olander School trips were added to the system as part of the traffic assignment process shown later in this report. Raw traffic count data is provided in Appendix A. Existing Operation The Taft Hill/Horsetooth and Taft Hill/Bronson intersections were evaluated regarding operational efficiency. The Taft Hill/ Horsetooth intersection was evaluated using the existing signal control with existing geometrics and the volumes shown in Figure 3. The peak hour operation is shown in Table 1. Calculation forms are provided in Appendix B. Appendix C describes level of service for signalized and unsignalized intersections from the 1985 Highway Capacity Manual (1985 HCM). Operation at this intersection is acceptable during the peak hours. Acceptable operation is defined as level of service D or better. At the Taft Hill/Bronson intersection, operation is acceptable except for left -turn exits from Bronson during the afternoon peak hour. According to the unsignalized intersection technique from the 1985 HCM, the level of service for the left -turn exits in the afternoon peak hour is in category E. Based upon recent research, contained in Appendix D, the delay is estimated at 14-24 seconds per approach vehicle. This delay is more appropriately defined as level of service C/D. Table 1 also shows the level of service for J J_ 2 H LL Q F— T co T\T VI T ` — 13/8 BRONSON ti co to\ 00cl) cl N T T It co T � T cD \ \ \ � T 58/251 �— 28/95 89/ 182 51 /43 + � 65/43 I 6 / 7 --,4 cD '— 4J in T tico T q' r) r- HORSETOOTH AM/PM Q N 1992 PEAK HOUR TRAFFIC Figure 3 Table 1 1992 Peak Hour Operation Intersection Horsetooth/Taft Hill (signal) Taft Hill/Bronson (stop sign) WB LT WB RT SB LT Level of Service AM PM B B D (A/B)* E (C/D)* A B A A ( )* Level of service considering recent research related vehicle delay. these left turns based upon this research. This type of operation is typical where minor streets intersect with arterials. It is considered to be acceptable as long as alternative means of access are provided in the same general area. The Rossborough area has numerous alternative means of both ingress and egress. III. PROPOSED DEVELOPMENT Horsetooth West is a proposed commercial/residential development located near the intersection of Taft Hill Road and Horsetooth Road in Fort Collins. Olander Elementary School was a part of the previous Horsetooth West Overall Development Plan. This school has been built and is in operation. Figure 4 shows a schematic of the site plan of the Horsetooth West Overall Development Plan, indicating location of the uses shown in Table 2, Trip Generation. The short range analysis (1995) included the existing school and the residential portions of the overall development plan. The long range analysis (2010) included full build out of the Horsetooth West Overall Development Plan and an increase in background traffic in general accordance with the "North Front Range Corridor Study." Trip Generation Trip generation is important in considering the impact of a development such as this upon the existing and proposed street system. Trip Generation, 4th Edition, ITE was used to project trips that would be generated by the proposed uses at this site. Table 2 shows the expected trip generation on a daily and peak hour basis. No adjustments were made for transit or ridesharing. Therefore, the trip generation can be considered conservatively high. Trip Distribution A number of directional distributions of the generated trips were determined for Horsetooth West. The trip distributions are shown in Figure 5. Traffic Projections Traffic projections for the short range time period (1995) were obtained by factoring the existing traffic by 102 percent per year. A school trip assignment was also performed since the existing traffic was counted in the summer. The long range projections (2010) used daily traffic obtained from the North Front Range Transportation Planning Process. These 3 if I TAFT HILL ROAD i -- � Right -in /Right -out No Scale -- - - E� � I 1 .I , 1 I I 1 I 1 � i I B 0 II 1 � I I I I LL::Aurm J -- 1 1 1 I I � I I � 1 I I 1 ' A Olander School G 1 I 1 I 1 1 a° 0 0 F- LLJ cc SITE PLAN Figure 4 Table 2 Trip Generation Daily A.M. Peak P.M. Peak Land Use Trips Trips Trips Trips Trips in out in out PARCEL A 43 S.F. D.U. 430 9 24 27 16 PARCEL B 78 S.F. D.U. 780 16 43 23 29 PARCEL D 61 S.F D.U. & 710 14 41 45 26 16 M.F. D.U. PARCEL E C-store/gas 2000 54 54 63 63 Day Care 420 38 34 37 40 Retail 610 5 2 31 29 Office 230 24 4 5 20 PARCEL F Elementary School 590 63 42 6 8 PARCEL G 58 M.F. D.U. 350 6 25 27 12 TOTAL 6120 229 269 264 243 • Q ! Q N N RESIDENTIAL TRIPS il 5% �10%— HORSETOOTH ae U-)l CONVENIENCE STORE 75% Passby 1 f— LL Q SITE 10% HORSETOOTH olae SCHOOL TRIPS Q N O '� 10%/5% C,jl LL Q SITE H 30%/5% 25%/40% HORSETOOTH a° ae a� 9 O Ln RETAIL -DAY CARE / OFFICE TRIP DISTRIBUTION Figure 5 daily volumes were factored to obtain the expected peak hour traffic. Trip Assignment Trip assignment is how the generated and distributed trips are expected to be loaded on the street system. The assigned trips are the resultant of the trip distribution process. Figure 6 shows the short range morning peak hour assignment and the afternoon peak hour assignment of the residential portion of the Horsetooth West generated traffic plus background traffic. Figure 7 shows the long range peak hour assignment of full development of Horsetooth West with the background traffic. Signal Warrants As a matter of policy, traffic signals are not installed at any location unless warrants are met according to the Manual on Uniform Traffic Control Devices. Using the traffic forecasts shown in Figures 6 and 7, it is not likely that a signal will be warranted at any of the key intersections near Horsetooth West. Signal Progression Signal progression was not evaluated since no new signals are anticipated in this area. Operations Analysis Capacity analyses were performed on key intersections adjacent to Horsetooth West. Using the traffic volumes shown in Figure 6 and the existing geometrics, the intersections operate in the short range condition as indicated in Table 3. Calculation forms for these analyses are provided in Appendix E. The Taft Hill/ Horsetooth signalized intersection operates acceptably. The Taft Hill/Bronson stop sign controlled intersection operates acceptably considering the vehicle delay research cited earlier. The two stop sign controlled intersections along Horsetooth Road operate acceptably. Using the traffic volumes shown in Figure 7, the intersections operate in the long range future as indicated in Table 4. Calculation forms for these analyses are provided in Appendix F. It is expected that by this future date (2010), Horsetooth West will be at full development. It is assumed that both Taft Hill Road and Horsetooth Road will have four lane urban cross sections with auxiliary lanes at appropriate locations. It is also assumed that Horsetooth Road will connect to Overland Trail to the west of 4 N 0 N co 't \ cD \ co 0tiin-14/8 NOM 3/2 19/ 12 -� BRONSON 32/21 —4, LO Q o- \ r \ O 0 N cD W z O F- LU p z (n O.y DT \ ) M < � \ \ O O �_ Ozco 03 N 77/296 18/29 �— 37/135 \�5/13 54/165 HORSETOOTH) j 23/81 78/245 j 103/212 NO —� N 0 M 128/78 �� } 105/75 249/ 157 123/78 NOM -� 0 00� 11/10 -� r c)N �r- Lo z z T \\ co AM / PM SHORT RANGE PEAK HOUR TRAFFIC Figure 6 W Z O H N W_ H Z O L Ln � Q N CO Lo Z Lo �- N r- 20/25 �-- 245/355 HORSETOOTH) 1 —25/85 10/15 15/25 285/265 405/340 —g- 5/10�` Lo0 � Z uo CD AM / PM 0 N r- O � U.) 00 o L 15/10 o �l J 5/50 / 1 � 35/50 —� � BRONSON t � 5/10 35/25 L0 0 Lo U)toul r- 0 ti o Lo _J U') .J N In _ co O o� LL v� Q I i 1- 25/30 �n o 0000 N co m 0 co 1"*�— 105/310 55/80 f— 130/280 265/440 J 1 -/ 140/285 190/ 140 —� 210/175 —� 70/90 LONG RANGE PEAK HOUR TRAFFIC Figure 7 Table 3 Short Range Peak Hour Operation Level of Service Intersection AM PM Horsetooth/Taft Hill (signal) B C Taft Hill/Bronson (stop sign) EB LT/T D (C/D)* E (C/D)- EB RT B B WB LT/T D (C/D)* E (C/D)- WB RT A C SB LT A B NB LT A A Horsetooth/Local Street (stop sign) SB RT/LT A A EB LT A A Horsetooth/Auntie Store (stop sign) NB LT/T A A NB RT A A SB LT/T A A SB RT A A EB LT A A WB LT A A ( )* Level of service considering recent research related vehicle delay. • Table 4 Long Range Peak Hour Operation Level of Service Intersection AM PM Horsetooth/Taft Hill (signal) C D Taft Hill/Bronson (stop sign) EB LT/T E (D)* F (D)* EB RT A A WB LT/T E (C/D)* E (D)* WB RT A B SB LT B D NB LT C D Horsetooth/Local Street (stop sign) SB RT/LT C C EB LT A A Horsetooth/Auntie Store (stop sign) NB LT/T B C NB RT A A SB LT/T C D SB RT A A EB LT A A WB LT A A Taft Hill/right-in/right-out (stop sign) EB RT A A ( )* Level of service considering recent research related vehicle delay. Horsetooth West. The exact location of that intersection and the future alignment of Overland Trail will be the subject of future planning and engineering studies by the City of Fort Collins. The Taft Hill/Horsetooth signalized intersection is expected to operate acceptably. It is expected that the only auxiliary lanes necessary will be the left -turn lanes on each leg. The Taft Hill/Bronson stop sign controlled intersection will operate acceptably considering the vehicle delay research cited earlier. Minor street left turns and throughs will find that the delay, particularly during the peak hours, will increase. However, signals are not warranted at this intersection. The movements which will experience this delay do have convenient, alternative routes through signalized intersections. Even if all the minor street left turns and throughs use the Taft Hill/Horsetooth intersection, it will continue to operate acceptably. The stop sign controlled intersections along Horsetooth Road are expected to operate acceptably. At this level of development, the overall development plan shows a right-in/right-out access approximately 300 feet north of Horsetooth Road along Taft Hill Road. At the right-in/right-out driveway access and Taft Hill intersection, the right -turn entrances warrant an exclusive right -turn lane. According to Section 1.02.08 of Design Criteria and Standards for Streets, City of Fort Collins, 1986, this right -turn lane and taper should be 500 feet at a 50 mph design speed. This would require a right -turn lane extending from the driveway through the Taft Hill/Bronson intersection. The posted speed on Taft Hill Road is 35 mph. The distance from the right-in/right-out access to Bronson is just over 300 feet. If the access were designed to accommodate a 15 mph turn, then the deceleration lane length at 35 mph is 240 feet (from "Intersection Channelization Design Guide," NCHRPR 279, TRB, 1985, Pg. 65). This will comfortably fit into the available separation between the access and Bronson. It is recommended that this criteria be used in designing this access. A right -turn acceleration lane is not recommended at this access. Exiting vehicles should be stopped and required to wait for an acceptable gap in the southbound traffic on Taft Hill Road. There is already a median on Taft Hill Road so further channelization is not necessary. Typically, the City of Fort Collins requires a "with/without" analysis to justify a right-in/right-out on an arterial. This analysis evaluates how other key intersections will operate with and without the proposed access. A cursory analysis indicates that this access will have little impact on adjacent intersections. The access is more one of convenience for the future commercial parcel. A properly designed right-in/right-out access will not negatively impact the operation of the through lanes on Taft Hill Road. It is, therefore, recommended that the City consider allowing the right-in/right-out access. 5 I Accident Analysis _The recommended control devices and geometrics should minimize vehicular conflicts and maximize vehicle separation. Therefore, the accident rate should be at its minimum for a typical urban condition. IV. CONCLUSIONS This study assessed the impacts of Horsetooth West on the short range (1995) and long range (2010) street system in the vicinity of the proposed development. As a result of this analysis, the following is concluded: - The development of Horsetooth West is feasible from a traffic engineering standpoint. At full development as proposed, approximately 6100 trip ends will be generated at this site daily. - The Taft Hill/Horsetooth intersection currently operates acceptably with signal control and the existing geometrics. The Taft Hill/Bronson intersection operates acceptably considering the recent delay criteria research. - By 1995, given development of the residential portion of Horsetooth West and an increase in background traffic, the signalized intersection of Taft Hill/Horsetooth will operate acceptably. The existing geometrics will be adequate at the Taft Hill/Horsetooth intersection. The stop sign controlled intersections will operate acceptably. - By 2010, the Taft Hill/Horsetooth intersection will operate acceptably in the morning and afternoon peak hours with a typical four lane cross section with left -turn lanes on each leg. The stop sign controlled intersections will operate acceptably. - In the long range future (2010), the proposed stop sign controlled right-in/right-out access to Taft Hill will operate acceptably. A right -turn deceleration auxiliary lane is warranted. This right -turn lane would remove vehicles from the through traffic stream on Taft Hill, providing a safer condition. This right -turn lane should be at least 240 feet long including taper and assuming a 15 mph turn radius. - With the recommended control and geometrics, the accident rate should be at an acceptable level for typical urban conditions.