4.10. SR 01-20-2015 - Laserfiche WebLink

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Spack Consulting 2 of 6 1715` Ave & Twin Lakes Rd Traffic Analysis Figure 2 in the Appendix shows two layouts developed for this new intersection of 171" Avenue and Twin Lakes Road. A two lane roundabout was originally proposed as a method to accommodate the shifting traffic patterns associated with the proposed network changes. After discussions with area businesses and their primary concern regarding the accommodation of over -sized semi - trucks, a traditional intersection was also developed as an option for this new intersection. Traffic Volumes Shifting the major Highway 169 access from 171" Avenue to 167th Avenue will result in significant travel pattern changes in this area. Traffic volumes for the future condition are necessary to properly evaluate the most appropriate intersection configuration. The a.m. and p.m. peak hour volumes were obtained from the 1715tAvenue Area AUAR completed in 2011. From this report, the traffic volumes forecasted with the proposed future Highway 169 access with Twin Lakes Road are labeled as Scenario 2. The Scenario 2 volumes were adjusted through the network to match the proposed roundabout and traditional layouts. Volumes were then added in for three existing businesses that will have their driveways altered by these changes. These businesses are: • LeFebvre Companies, located north of 171" Avenue and west of the railroad tracks, • Morrell Companies, located south of 171" Avenue and west of the railroad tracks, and • Preferred Power Coating, located southwest of the proposed new intersection. Traffic volumes for these sites were determined by using building square footage and rates from the Institute of Transportation Engineers' Trip Generation Manual, 9t" Edition. Although the traffic from these sites is likely already included in the traffic volumes for the public intersections, they are necessary to fully evaluate the proposed roadway changes and also presents a conservatively high estimate of the traffic in the area. The traffic volumes developed for each scenario can be seen in the Appendix. Alternative Configurations For this memorandum, the traffic control and the geometry of the new 171" Avenue and Twin Lakes Road intersection were reviewed for other potential configurations. Based upon the traffic volumes and surrounding site, a grade- separated crossing is not appropriate. This includes several alternative intersection types, such as an echelon interchange or center turn overpass interchange. Given the roadway is designed to provide access to surrounding businesses, access management options such as a restricted crossing U -turn intersection, are also not advisable. The relatively low volumes, compared to the warrant thresholds, also eliminated traffic signal control. However, a review of the traffic volumes did reveal that a four -lane roadway has a much greater capacity than the volumes presented in the previous section. Therefore, a three -lane roadway was considered for Twin Lakes Road, providing one through lane in each direction with a center, two -way left turn lane. The approach lanes at the study intersection would then be configured as follows: • One northbound left turn lane and one northbound through lane • One southbound through lane and one southbound right turn lane • One eastbound left turn lane and one eastbound right turn lane Since traffic signal control is not appropriate, stop sign control was considered. For this future condition, stop control on 171" Avenue is most appropriate with Twin Lakes Road traffic able to proceed without stopping. This alternative configuration, in addition to the roundabout and four -lane stop control options, is shown in Figure 3 in the Appendix.