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Home My WebLink AboutGREYROCK COMMONS PUD & REZONING - LARIMER COUNTY WAIVER REQUEST - 38-94 - SUBMITTAL DOCUMENTS - ROUND 1 - TRAFFIC STUDYI I I I i 1 i i i i MERRICK & COMPANY Based on counts conducted in April of 1994, there are between 200 and 250 daily trips on Liberty Drive where it intersects with Taft Hill. Based on the conservative worse case trip generation estimates for the proposed Greyrock Commons residential development, this daily traffic would increase to approximately 460 trips per day. This forecasts is significantly below, (less than one- third) the residential traffic volume threshold associated with decreased residential quality of life. Internal Traffic Control An examination was made to determine whether stop signs should be provided on North Briarwood Drive where in intersects Liberty Drive, or at the "T" intersection of North Briarwood Drive and the internal project streets. The Manual of Uniform Traffic Control Devices states than STOP signs cause a substantial inconvenience to motorists, and should only be used where warranted. The manual further lists these warrants, such as where a less important road intersects with a main road or in situations where there are combinations of high speed, restricted view and serious accident records. Based on review of the existing intersection of Liberty Drive and North Briarwood Drive and the proposed development plan, it is our opinion that stop signs at either location are not warranted. i11 F MERRICK & COMPANY xQ �o x � F M o CQ 't 'n M U.-6/1 460 `► 4I .40— 3/5 160 LIBERTY DRIVE 1/2 PRIVATE DRIVE 0/0 —• 28/12 0 �Cqt m �w 0o 133/75 4400 l _ '0-100/ 191 6700 f�166 117 VINE DRIVE 18/18 199/81 —► LEGEND 52/47 o AM/PM Peak Hour \CQ� Turn Volumes r o m co M o m ADT Average Daily Traffic O � M 33/78 f-218/282 10200 63/254 10000 LA PORTE AVENUE 65/59 —� 1107/169 %155 O ncoCat CO d' cc O CO CQ N Figure 5 Year 2000 Plus Project Peak Hour Traffic Volumes MERRICK & COMPANY Table D - Year 2000 Plus Project Intersection Level of Service Level of Service Intersection AM PM Taft HiWLiberty (Two Way Stop) East Bound Left A B East Bound Through A A East Bound Right A A West Bound Left B B West Bound Through A B West Bound Right A A South Bound Left A A North Bound Left A A Taft Hill/Vine (Four Way Stop) D D Taft H11111-a Porte (Signal) A A In addition to the level of service analysis, a signal warrant analysis was performed at the four way stop intersection of Taft Hill Road and Vine Drive based on the Signal Warrants as identified in the Manual of Uniformed Traffic Control Devices (MUTCD). Projected year 2000 peak hour plus project traffic volumes will not warrant a signal at this intersection. Liberty Drive Impact Analysis The level of service analysis discussed above examines the relationship between the projected traffic volumes with the available capacity. Whereas acceptable levels of service will also exist for Liberty Drive with the addition of project traffic, it is also of concern to the existing residents that the quality of life be preserved. The definition of quality of life is, however, subjective. Historically, both locally and nationally, there have been observations made as to when residents begin to complain about the traffic, safety, speeding and overall quality of life. These observations indicate that when traffic begins to exceed 1,500 or 2,000 daily trips, complaints by the residents on a local residential street significantly increase. we MERRICK &. COMPANY Table C - Existing Pins Project Intersection Level of Service Level of Service Intersection AM PM Taft HdULiberty (Two Way Stop) East Bound Left A B East Bound Through A A East Bound Right A A West Bound Left A B West Bound Through A A West Bound Right A A South Bound Left A A North Bound Left A A Taft Hill/Vine (Four Way Stop) C C Taft Hill/La Porte (Signal) A A In addition to the existing and the existing plus project level of service analysis, this traffic impact analysis also examines a year 2000 condition. These year 2000 projections assume a student population increase at Poudre Valley High School to 1800 students and a background traffic increase of 3 percent per year, based on recent historic growth rates. The results of this forecasts is presented in Figure 5. The levels of service results are presented in Table D. As can be seen in the table, acceptable levels of service will exist at all three intersections assuming year 2000 forecasts. The project as proposed will not have a negative impact to the local circulation system 460 LIBERTY DRIVE 3900 VINE DRIVE 8500 LA PORTE a a CC � F C) wa d Jcw CQ 6/0 r 3/5 1 1/2 _ 0/ 28/12 15/15 167/68 /40 44 44/40 MERRICK & COMPANY PRIVATE DRIVE 28/63 --84/160 5900 �139/98 -0610- LEGEND co to 0 AM/PM MCA 00 � ADT 20/58 ---187/208 49/185 7900 Peak Hour Turn Volumes Average Daily Traffic AVENUE 48/48 211/129 —� 110/130 n It @o O CQ co 0 1- CO i Figure. 4 A Existing Plus Project Peak Hour Traffic Volumes MERRICK & COMPANY Project Impacts The a.m. and p.m. peak hour trip generation rates for the proposed residential units are based on the Institute of Transportation Engineers 5th edition of the Trip Generation Manual. For a worse case analysis, the single family detached trip generation rate was used, even though all of the units as proposed will be attachd�which tend to generate a lesser number of trips than a typical single family dwelling unit. The trip generation rates and resulting trip generation for the proposed project are presented in the following table. Table B - Project Trip Generation AM AM AM PM PM PM UNITS ADT IN OUT TOTAL IN OUT TOTAL iTrip Generation Rates DU 9.55 .19 .55 .74 .66 .35 1.01 iTrip Generation 30 287 6 16 22 20 10 30 The trip distributions for the proposed project is based in part on the location of the project within proximity to the City of Fort Collins and in part on the existing traffic counts. Based on these relationships it was estimated that approximately 90 percent of the project traffic would travel to Taft Hill via Liberty Drive and 10 percent to Vine Drive via Mllcrest and/or Montview. Of the 90 percent traveling to/from Taft Hill via Liberty, 80 percent would travel to and from the south and 10 percent to and from the north. The 10 percent which is estimated to travel directly to Vine, is assumed to travel equally to and from the east and west. Of the 85 percent of the total traffic arriving at the intersection of Taft Hill and Vine, 15 percent is estimated to travel to and from the east on Vine with the remaining 70 percent traveling to and from the south via Taft Hill. At the intersection of Taft Hill and La Porte, 50 percent is estimated to travel south on Taft Hill and the remaining 20 percent to and from the east on La Porte. The resulting existing plus project peak hour levels of service for the intersections of Taft Hill at Liberty, Vine and La Porte are presented in Table C. As can be seen, acceptable levels of services prevail at all three intersections in both the a.m. and p.m. peak hour conditions with the addition of project traffic. 1 1 i6 J x� E,o O F a) O O O � 6/1 0/0 rr200 r 3/5 LIBERTY DRIVE 3900 VINE DRIVE 0/1 0/0 15/4 O Cl) CO CO tiM CO I� r 15/15 167/68 44/40 44/40 8500 LA PORTE " to \\\ r- M M -IN r MERRICK & COMPANY PRIVATE DRIVE 26/60 --84/160 5900 �139/98 LEGEND 0 N OD AM/PM Mco CQ O O 19/55 -*--187/208 49/185 7900 Peak Hour Turn Volumes Average Daily Traffic AVENUE 48/48 -1tr i 211 / 129 ---► 110/130 ,n CO .-• o co co Figure 3 Existing Peak Hour Traffic Volumes MERRICK & COMPANY Existing April 1994 a.m. and p.m. peak hour intersection traffic counts were conducted for this analysis at the intersections of Taft Hill Road at Liberty Drive, Vine Drive and La Porte Avenue and are presented in Figure 3. Intersection level of service analysis was performed at the three intersections under investigation. Level of Service (LOS) is a grading system as to how well an intersection operates, ranging from "A" which is excellent to "F" failure. LOS of "D" or better is the Larimer County threshold for being acceptable. The existing levels of service for the intersections analyzed are based on the 1985 Highway Capacity Manual and are presented in Table A. The calculations sheets for this analysis is presented in the appendix of this report. As can be seen acceptable levels of services exist for both the a.m. and p.m. peak hour conditions. Table A - Existing Intersection Level of Service Level of Service Intersection AM PM Taft HiUJLiberty (Two Way Stop) East Bound Left A A East Bound Through A A East Bound Right A A West Bound Left A A West Bound Through A A West Bound Right A A South Bound Left A A North Bound Left A A Taft Hill/Vine (Four Way Stop) C C Taft Hill/La Porte (Signal) A A i i 4 I I V1 J EJi.3.. - - - - - - - C:)1 i 1.1 I � Naurc i � 1'lanl:y �I / I wl 1' `Srnhul^ccJ /r 1 � I 1 l j' Wu ANuntc _ I II j; Arve Slnn.aur 1.... I pllwuw.5rtr W , field 'Y4 l I 5 ` Master L -I a: - -- T A ..... I•.... —�� .... _ C Mast_—. an- _-- — .r... .. L2,930, _ 1 1 I h 1 If L Tat1A I S$ _ I t j.` 3 .. ul S I :u:n Q r n 1 I -T V •rwlarrw. ' CIrJ1 41 _ t•P -_ --_ L. _ -w.r I..r.. —. ---y •I'� /e.I2'_-_ _ � HB9 •J IS W ---Y � � m ` �� -��- //B)11' � 1.1— 11-d ... 1.11:.nnrn -a�vv ;IiRny M.W.15uNrrumn li ' Trrtr'A'. L,kI 41[Wo.r S...... Z ---------------------------- MERRICK & COMPANY Ii Figure 2 Site Plan u north I I i I MERRICK & COMPANY Scale: 1" = 600' 0 150 300 60012 0 feet Figure 1 Vicinity Map I MERRICK & COMPANY GREYROCK COMMONS P.U.D. TRAFFIC IMPACT ANALYSIS The following traffic impact analysis is for the proposed Greyrock Commons residential development located west of Taft Hill Road and north of Liberty Drive in Larimer County and within the City of Fort Collins Urban Growth Area. As will be presented, the analysis evaluates the impacts of the proposed project traffic when added to existing and forecast 2000 traffic conditions at the intersection of Taft Hill at Liberty Drive, Vine Drive and La Porte Avenue. Based on this analysis, no traffic impacts were identified and the intersections evaluated will operate at acceptable levels of service, both in existing and year 2000 conditions. Furthermore, the traffic study will indicate that the project will have not result in a significant impact to the residential quality of life on Liberty Drive. Project Description The project site is located west of Taft Hill Road and north of Liberty Drive in Larimer County as can be seen in Figure 1. Access to the site is primarily via Taft Hill Road, Liberty Drive and the extension of Briarwood. Secondary access to Vine Drive will be via Hillcrest Drive or Montview Road, Trevor Street and Briarwood. The proposed project site plan is presented in Figure 2. The proposed project consists of 30 single family attached residential dwelling units located on the southern portion of the property. The northerly portion of the site is proposed to remain as open space, including community gardens, playing fields, detention area and a wildlife friendly area. Existing Setting iAs indicated, the proposed project will be located west of Taft Hill Road and north of Liberty Drive. Taft Hill Road is designated as a Major Collector by Larimer County. The right-of-way requirement for a major collector is 100 feet with a minimum pavement width of 24 feet. Currently, Taft Hill Road is improved to the minimum 24 foot pavement requirement with adequate paved shoulders.. Liberty Drive is a local residential street, serving 27 dwelling units. Liberty Drive has a 36 foot pavement width with raised curb. Traffic control is provided by a stop sign on Liberty at Taft Hill Road. iThere is one lane for each intersection approach at Taft Hill and Vine Drive. Traffic control at this intersection is provided by a four way stop. iAt the intersection of Taft Hill Road and La Porte Avenue, the lane configurations consist of one through/right turn lane and one left turn lane on La Porte Avenue and one left, one through and one right turn lane on Taft Hill Road. This intersection is controlled with a traffic signal. I MERRICK & COMPANY TABLE OF CONTENTS PAGE 1 Description Project .............................................. 1 ................... Existing Setting .................. 6 Project Impacts ................................................. 9 Liberty Drive Impact Analysis ....................................... 11 Internal Traffic Control ......................................... LIST OF FIGURES Map 2 1. Vicinity ................................................ Plan 3 2. 3. Site .................................................. Existing Peak Hour Traffic Volumes ................................. 5 4. Existing Plus Project Peak Hour Traffic Volumes ......................... 7 5. Year 2000 Plus Project Peak Hour Traffic Volumes ....................... 10 LIST OF TABLES A. Existing Intersection Level of Service ................................ 4 B. Project Trip Generation ........................................ 6 C. Existing Plus Project Intersection Level of Service ........................ 8 D. Year 2000 Plus Project Intersection Level of Service ....................... 9 Appendix: Level of Service Analysis GREYROCK COMMONS P.U.D. TRAFFIC IMPACT ANAL YSIS May 17, 1994 Presented to Fort Collins Cohousing Community 000 000 MERRICK Denver/Fort Collins Colorado