August 30, Don Grigsby Travis County Transportation.and Natural Resources 411 West 13th Street, 9th Floor Austin, TX 78701

Transcription

1 August 30, 2010.Don Grigsby Travis County Transportation.and Natural Resources 411 West 13th Street, 9th Floor Austin, TX Dear Don: HDR Engineering, Inc. has completed a traffic study for the Colliers Wood SubdiviSion project located in the vicinity of Sprinkle Road and.springdale Road, in Austin, Texas, as shown in Figure 1. The purpose of this study... is to evaluate the impact of this proposec project on the existing and future roadway network.to determine intersection and roadway design requirements- Site and Access Characteristics The Colliers Wood SUbdivision development will consist of an estimated 346 single family homes, 425 multifamily. dwelling units, and 69,000 square feet of specialty retail. It is anticipaied that the property will be fully developed by the year Access to this project is proposed via two main roadways that will be constructed with the project.- Winston Churchill Drive and Colliers Glenn. As shown in Figure 2, Winston Churchill Drive is proposed to intersect Springdale Road on the south side of the property, continue north within the property, and intersect Sprinkle Road, west of Springdale Road. Colliers Glenn intersects Winston Churchill. Drive in the southern section of the property, continues north, crosses Winston Chwrchill Drive in the northern section of the property, and intersects......sprinkle Road,west of the Winston Churchill Drive intersecton. Thesetwo mainroadways will provide access to. the single family portion of the property. Three additional driveways (Driveways A, S, and C) are proposed as.. shown on Figure 2, and will provide access to the multifamily and retail portions of the property.

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3 ~~~ SPRIHCO.U r ROAO LEGEND o = SITE DRIVEWAY Inc Lavaca Sheet. Suite Auslin Texas 7870 I. TBPE FIrmRe<j5traJlon No. 754 lil RHDR Enqineering, FIGURE 2 CONCEPTUAL SITE PLAN

4 . Page 41 Don Grisby 1August 30,2010 Data Collection Data collection was conducted during the week of May 17, Traffic counts were conducted from 7:00 to 9:00 AM and from 4:00 to 6:00 PM at the following intersections: 1. Tuscany Way and US Springdale Road and US Ferguson Lane and Cameron Road (Dessau Road) 4. Ferguson Lane and Sprinkle Road/Tuscany Way 5. Ferguson Lane and Springdale Road 6. Tuscany Way and Exchange Drive/ACC Driveway 7. Sprinkle Road, Springdale Road, and Cameron Road (Blue Goose Road) 8. Sprinkle Road and Sprinkle Cutoff 'Road Based on historical 24-hour traffic counts on US 290, east of Springdale Road, and the presence of various nearby projects that add to the background traffic, a conservative traffic growth rate of 5% per year from 2010 to 2017 was assumed for this analysis. (It should be noted that traffic volumes have actually decreased on US 290 in recent years.) Existing and Future Thoroughfare System US The CAMPO 2030 Mobility Plan classifies US 290 as a four-lane major divided arterial between US 183 and Giles Road. Based on a review of the 2010peak period traffic counts,36,200 vpd are estimated on US 290, west of Springdale Road. According tothe CAMPO 2030 Mobility Plan, US 290 is committed to be upgraded to a six-ianetoll freeway, between US 183 and SH 130 by It should be notedthatthis project upgrade was initially scheduled to bepin by However, due to budget constraints and unapproved designs, this project has been rescheduled to begin in 2011 and end by Tuscany Way - Tuscany Way is currently a two-lane roadway with a center left-turn lane between US 290 and Exchange Drive, and. a four-lane roadway with a center left-turn lane between Exchange Drive and Ferguson... Lane. Based on a review of the 2010 peak period traffic counts, 7,600 vpdare estimated on Tuscany way.east of Exchange Drive. No improvements are currently planned for this roadway in the vicinity of the site. Springdale Road - Springdale Road is currently a four-lane roadway with a center left-turn lane south of US 290 and a two-lane undivided roadway north of US 290. Based on a review of the 2010 peak period traffic counts, vpd are estimated on Springdale Road, south of US 290. No improvements are currently planned for this roadway in the vicinity of the site.

5 Page 51 Don Grisby I August 30,2010 Ferguson Lane - Ferguson Lane is currently a two-lane undivided roadway between Cameron Road (Oessau Road) and Springdale Road. Based on a review of the 201 o peak period traffic counts, 4,900 vpd are estimated on Ferguson Lane, east of Cameron Road (Oessau Road). roadway in the vicinity of the site. No improvements are currently planned for this Cameron Road (Oessau Road) - Cameron Road (Oessau Road) is currently a six-lane divided roadway between E.Anderson Lane and E. Rundberg Lane. Based on areview of the 2010 peak period traffic counts, 31,300 vpd are estimated on Cameron Road (Oessau Road), north of Ferguson Lane. No improvements are currently planned for this roadway in the vicinity of the site. Sprinkle Road - Sprinkle Road is currently a two-lane undivided roadway between Ferguson Lane and Springdale Road. Based on a review of the 2010 peak period traffic counts, 4,700 vpd are estimated on Sprinkle Road, east of Sprinkle Cut Off Road. No improvements are currently planned tor this roadway in the vicinity of the site. Sprinkle Cut Off Road - Sprinkle Cut Off Road is currently a two-lane undivided roadway north of Sprinkle Road. Based on a review of the 2010 peak period traffic counts, 3,300 vpd are estimated on Sprinkle Cut Off Road, north of Sprinkle Road. No improvements are currently planned for this roadway in the vicinity of the site. Traffic Analysis In order to assess the traffic implications of the proposed development; two time periods and three travel conditions were evaluated: Existing Conditions Forecasted Conditions Forecasted Conditions with Site Generated Traffic Site Traffic. Based on recommendations and data contained in the Institute of Transportation Engineers (ITE) Trip Generation, the proposed project will generate approximately 9,015 unadjusted daily trips at final buildoutin Table 1 provides a detailed summary of traffic production, which is directly related to the assumed land use plan.

6 Page 6 I Don Grisby I August30, 2010 Tablet Summary of Daily and Peak Hour Trip Generation 24-hour Two-way AM Peak Hour PM Peak Hour Proposed Land Use Size Volume Enter Exit Enter Exit Single Family 346DU 3, Apartments 425DU 2, Specialty Retail 22,000 SF Specialty Retail 47,000 SF 2, , Total 9, Directional Distribution Once site generated trips were known, the next step involved distribution of those trips to appropriate geographic directions and logical connecting roadways. The major thoroughfares that have a direct bearing on the accessibility of the project have been previously identified. Traffic counts conducted during the study provided the basis for the overalldirectionai distribution of traffic approaching and departing the project site during the peak hours of the roadway network, as summarized in Table 2. Table 2. Forecasted Overall Directional Distribution of Site Oriented Traffic Roadways % of Site Traffic North Cameron Road 20 South Cameron Road 19 East Cameron Road 2 North SprinkleCutoff Road 2 South Tuscany Way 1 South Sprinqdale Road 7 South Exchance Drive 5 East US West US Total 100

7 Page 71 Don Grisby 1August 30, 2010 Analysis Assumptions The traffic impact analysis process involves both the use of. primary data and engineering judgment on transferable parameters. Specifically, engineering judgment is required for estimation of pass-by capture, and internal capture which are further described in the following paragraphs.. ' Pass-By Capture - Studies have shown that retail land uses will capture from 20 to 60 percent of their traffic as pass-by trips, depending upon their size. It is well documented that many other land uses also experience significant pass-by trip capture, such as drive-in banks and restaurants. The amount of trip reduction that each tract may attribute to the pass-by phenomenon will depend directly on the type of land use that is developed. No pass-by reductions were assumed for the proposed project. Internal Capture - Once the total buildout of proposed land uses occurs, there will be interaction among the uses within this development. Internal capture is accounted for in two ways. First, to account for internal capture among similar retail land uses in adjacent areas, the sizes may be combined during the trip generation process. Because the equations used in trip generation estimations are logarithmic, the number of trips generated by a site does not increase indirect proportion to an increase in the square footage of a development. By combining retail projects in close proximity to each other, a lower number of trips will be estimated, thereby taking into account the internal capture factor. The second way to account for internal capture is to reduce the expected number of trips directly by some percentage, which reflects expected multipurpose trip-making among different types of land uses that are in close proximity. on the type and quantity of land uses. Afive However, as with pass-by trip reductions, internal capture depends (5) percent internal capture reduction was assumed for all the land uses during the AM and PM peak periods. Given the assumed land use activity, the pass-by capture and internal capture reductions discussed previously, the total adjusted trips per day for this project were estimated at 8,564. As a point of reference, the total unadjusted trips per day for this project were estimated at 9,015. Intersection Capacity Analysis Intersections in the vicinify of the site are considered locations of principal concern because they are locations of highest traffic conflict and delay. The standard used to evaluate traffic conditions at intersections is level of service (LOS), which is a qualitative measure of the effect of a number of factors such as speed,volume of traffic, geometric features, traffic interruptions, freedom to maneuver, safety, driving comfort, convenience, and operating cost. Two types of intersections include signalized and unsignalized, which use different criteria for assessment of operation levels.

8 Page 81 Don Grisby I August 30, 2010 Signalized intersection LOS is defined in terms of delay, which is a direct and/or indirect measure of driver discomfort, frustration, fuel consumption, and lost travel time. The levels of service have been established based on driver acceptability of various delays. The delay for each approach lane group is calculated based on a number of factors includinq lane geometries, percentage of trucks, peak hour factor, number of lanes, signal progression, volume, signal green time to. total cycle time ratio, roadway grades, parking conditions,and.. pedestrian flows. It should be noted that there are three signalized intersections within this study area. Unsignalizedintersection level of service (LOS) is defined in terms of average control delay. Control delay is that portion of total delay attributed to traffic control measures, such as stop signs. Control delay includes initial deceleration delay, queue move-up time, stopped delay, and final acceler.ation delay. The control delay for this project was determined using the microcomputer program "Synchro 7.0' by Trafficware, which is based on procedures contained in the Highway Capacity Manual. In general, overall intersection levels of service A to 0 are deemed acceptable, while ail overall LOS of E or F is unacceptable. It should be noted that there are five unsignalized intersections within this study area. The results of these analyses are summarized in Table 3.

9 Page 91 Don Grisby 1August 30, 2010 Intersection Table 3. Level of Service Site Site + Existing Forecasted Forecasted Forecasted without with Intersection Improvements Improvements AM PM AM PM AM PM AM PM Tuscany Way and SH 290 F C D C D C - - Springdale Road and SH 290 E E C C C C - - Ferguson Lane and Cameron Road (Dessau Rd) B B C C D D - - Ferguson Lane and Sprinkle RoadlTuscanyWay A A A A A Ferguson Lane and Springdale Road A A A B A TuscanyWayand Exchange Drive/ACC Driveway A A A A A A - - Sprinkle Road, Springdale Road and Cameron Road/Blue Goose Road A A A A A A - Sprinkle Road and Sprinkle Cutoff Road A A D A E A D A Springdale Road and Winston Churchill Drive A. A - - Sprinkle Road and Winston Churchill Drive A A - - Sprinkle Road and Colliers Glen A A - - Springdale Road and Driveway A A A - - Springdale Road and Driveway A A - - Sprinkle Road and Driveway C A A Intersection Analysis "Forecasted" analysis includes CAMPO plans. "Site + Forecasted" analysis includes improvements necessary upon addition of site traffic. As shown in Table 3, all intersections perform at an acceptable LOS under 2017 site plus forecasted traffic conditions, during both the AM and PM peak periods. It should be noted that the US 290 upgrade project will reduce the amount of vehicular traffic using the frontage roads. For analysis purposes, it was assumed that 60 percent of vehicular traffic will use the toll freeway while 40 percent of vehicular traffic will remain on the frontage roads. The results of the analyses are further described as follows:

10 Page 10 I Don Grisby I August 30,2010 Tuscany Way and US 290 As mentioned earlier, according to the CAMPO 2030 Mobility Plan, US 290 is committed to be upgraded to a sixlane toll freeway, between US 183 and Giles Road by It should be noted that this project upgrade was initially scheduled to begin by However, due to budget constraints and unapproved designs, this project has been rescheduled to begin in 2011 and end by This intersection will operate at LOS 0 and C under 2017 site plus forecasted traffic conditions during the AM and PM peak periods, respectively. No additional improvements are recommended as part of this project. Site traffic is estimated as approximately 2.1 % of the AM peak and 4.0% of the PM peak at this intersection. Springdale Road and US 290 As mentioned earlier, according to the CAMPO 2030 Mobility Plan, US 290 is committed to be upgraded toa sixlane toll freeway, between US 183 and Giles Road by It should be noted that this project upgrade was initially scheduled to begin by 2010, However, due to budget constraints and unapproved designs, this project has been rescheduled to begin in 2011 and end by No additional improvements are recommended as part of this project. This intersection will operate at LOS C under 2017 site plus forecasted traffic conditions during both the AM arid PM peak periods. Site traffic is estimated as approximately 6.6% of the AM peak and 7.1% of the PM peak at this intersection. Ferguson Lane and Cameron Road (Dessau Road) This intersection will operate at LOS 0 under 2017 site plus forecasted traffic conditions during both the AM and PM peak periods. No improvements are recommended as part of this project. Site traffic is estimated as approximately 3.2% of the AM peak and 5.7% of the PM peak at this intersection. Ferguson Lane and Sprinkle RoadlTuscany Way This intersection will operate at LOS A and B under 2017 site plus forecasted traffic conditions during the AM and PM peak periods, respectively. No improvements are recommended as part of this project. Site traffic is estimated as approximately 150% of the AM peak and 28.6% of the PM peak at this intersection.

11 '. Page 111 Don Grisby 1August Ferguson Lane and Springdale Road This intersection will operate at LOS A and B under 2017 site plus forecasted traffic conditions during the AM and PM peak periods, respectively. No improvements are recommended as part of this project. Site traffic is estimated as approximately 27.7% of the AM peak and 45.6% of the PM peak at this intersection. Tuscany Way and Exchange Driveway/ACC Driveway This intersection will operate at LOS A under 2017 site plus forecasted traffic conditions during both the AM and PM peak periods.. No improvements are recommended as part of this project. Site traffic is estimated as approximately 2.4% of the AM peak and 3.0% of the PM peak at this intersection. Sprinkle Road. Springdale Road. arid Cameron Road (Blue Goose Road) This intersection will operate at LOS A under.2017 site plus forecasted traffic conditions during. both the AM and PM peak periods. No improvements are recommended as part of this project. Site trafficisestimated asapprox.imately3.9%of the AM peak and 10.5% of the PMpeak at this intersection. Sprinkle Road and Sprinkle Cut Off Road This intersection will operate at LOS D and A under 2017 site plus forecasted traffic conditions during both the AM and PM peak periods, respectively, assuming the construction of a southbound right-turn lane on Sprinkle Cut Off Road with 190 feet of storage and 102 feet of taper.. Site traffic is estimated as approximately 5.3% of the AM peak and 11.7% of the PM peak at this intersection: Springdale Road and Winston Churchill Drive This intersection will operate at LOS A under 2017 site plus forecasted traffic conditions during both the AM and PM peak periods. The developer proposes that Winston Churchill Drive be constructed with a minimum 48-foot cross section consisting of two outbound lanes and two inbound lanes, and form the stop-controlled approach at this intersection. Sprinkle Road and Winston Churchill Drive This intersection will operate at LOS A under 2017 site plus forecasted traffic conditions during both the AM and PM peak periods. The developer proposes that Winston Churchill Drive be constructed with a minimum 48-foot

12 Page 121 Don Grisby!August 30, 2010 cross section consisting of two outbound lanes and two inbound lanes, and form the stop-controlled approach at this intersection. Sprinkle Road and Colliers Glen' This intersection will operate at LOS A under 2017 site plus forecasted traffic conditions during both the AM and PM peak periods. The developer proposes that Colliers Glen be constructed with. a minimum 30-foot cross section consisting of one outbound lane and one inbound lane, and form the stop-controlled approach at this intersection. Springdale Road and Driveway A This intersection will operate at LOS A under 2017 site plus forecasted traffic conditions during both the AM and PM peak periods. The developer proposes that Driveway A be constructed with aminimum 3D-foot cross section consisting of one outbound lane and one inbound lane, and form the stop-controlled approach at this intersection. Springdale Road and Driveway B This intersection will operate at LOS A under 2017 site plus forecasted traffic conditions during both the AM and' PM peak periods. The developer proposes that Driveway B be constructed with a minimum 3D-foot cross section consisting of one outbound lane and one inbound lane, and form the stop-controlled approach at this intersection. Sprinkle Road and Driveway C This intersection will operate atlos A under 2017 site plus forecasted traffic conditions during both the AM and PM peak periods. The developer proposes that Driveway Cbe constructed with a minimum 30-footcross section consisting of one outbound lane and one inbound lane, and form the stop-controlled approach at this intersection.

13 Page 131 Don Grisby 1August Please feel free to contact me if you have any questions or need additional information. Sincerely, ~~ Kathleen A. Hornaday, P.E., PTOE Senior Project Manager Enclosures cc: Rick Vaughn, Vaughn & Associates - four (4) copies of the TIA KH/BM