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show that simply lowering posted speed limits typically has little effect on actual <br />speeds without law enforcement presence. Lowering posted speeds usually only <br />reduces the prevailing speeds by one to two miles per hour, but it can increase the <br />difference in speeds, which is a common cause of vehicular crashes. In general, <br />drivers choose their speed based on what they think is a safe and reasonable speed <br />for the conditions present. <br />While analyzing this speed reduction proposal, it has been found that the potential <br />prevention of vehicle versus non -vehicular accidents outweighs the potential <br />increased risk of vehicular crashes caused by differential speeds. This is resulting in <br />the recommendation to lower the speed limit without the support of roadway <br />geometrics or 85th percentile speeds. This recommendation is based on the upcoming <br />changes in the configuration of bicycle lanes, roadside development and environment, <br />and pedestrian activity as discussed in Section 28.13 of the 2009 MUTCD. <br />One factor to consider when determining a reasonable speed limit is driver <br />expectations. Most of the other roads in the vicinity of No. 81 Road that are similar in <br />character have a posted speed limit of 25 MPH within the City of Kittitas and outlying <br />areas. The geographic location of this roadway segment suggests that the speed <br />reduction has a higher likelihood of success due to the close proximity of the City of <br />Kittitas and surrounding roads with low posted speeds. <br />There have been no recorded accidents on this segment of No. 81 Road in the past <br />five years. The 85`h percentile speed is 35.40 MPH with the current configuration not <br />containing a widened shared use path and No. 81 Road does not have roadway <br />geometry to justify a lower speed limit. <br />However with the increased use of non -vehicular traffic from an urban development <br />trying to access the City of Kittitas and neighboring park, and the upcoming change in <br />roadway configuration, the recommendation by Public Works is to reduce the current <br />posted speed of 35 MPH to 25 MPH. This would result in the 25 MPH speed limit <br />being extended approximately 1,500 feet from Palmero Park to the intersection of <br />Alpine Drive (Alpine Estates) and No. 81 Road for public safety. This <br />recommendation is heavily based on the potential risk reduction of accidents involving <br />vehicular and non -vehicular traffic and the severity that may occur with higher posted <br />speeds. <br />FISCAL IMPACTS: <br />The cost of re -posting No. 81 Road to 25 MPH is expected not to exceed $1,000.00. <br />ATTACHMENTS: <br />EXHIBIT 1 : NO 81 RD VICINITY MAP <br />EXHIBIT 2 2016 TRAFFIC STUDY DATA — NO 81 RD <br />EXHIBIT 3 2009 MUTCD, SECTION 26.13 <br />Page 2 of 5 <br />PUBLIC WORKS BOARD OF COUNTY COMMISSIONERS ENGINEER'S REPORT <br />