Capital Hill PUD Traffic Safety Analysis <br />(Revised) August 8, 2017 <br />Applying the calculated rate of 4.53 trips/dwelling unit/day to the site's potential 31 new <br />dwelling units in the post-development conditions, the site's contribution to the daily traffic <br />volume on Capital Drive would be 141 new daily vehicle trips. Assuming two existing residences <br />that appear to be currently unoccupied on Capital Drive north of Cresta De Ruta Street are <br />occupied at build-out, their contribution to the daily trip generation would be nine (9) additional <br />daily trips, and the total ADT of Capital Drive would be 209 average daily trips north of Cresta <br />De Ruta Street. The projected 209 ADT in the post developed conditions accounts for existing <br />traffic, occupancy at the two currently unoccupied residences, and post-development traffic <br />resulting from build-out of the site as planned. Assuming the 27 AM and 35 PM peak hour trips <br />occur during those peak one-hour periods, the average hourly trip generation contribution from <br />the site would be less than five trips per hour during the other 22 hours of a typical weekday. <br />The 27 AM peak hour trips would result in one vehicle trip about every two minutes during the <br />highest morning continuous one-hour period, with most of those trips exiting the site. The 35 <br />PM peak hour trips would result in approximately 3 vehicle trips every 5 minutes during the <br />highest afternoon continuous one-hour period. <br />A comparison of the trip generation rate derived from collected tube count data on Capital Drive <br />per unit to the applicable published national average daily trip generation rates is made in the <br />following table: <br />Existing Residential Properties north of Cresta De Ruta Street: <br />Existing Occupied 13 59 4.53 <br />Residential Dwellings <br />Proposed New Residences at Capital Hill Site: <br />Single <br />Family Dwellings 28 9.52 267 127 4.53 <br />Detached <br />Multi- Dwellings 3 6.65 20 14 4.53 <br />Family <br />Proposed New Development Totals: 287 141 4.53 <br />In addition to the traffic volumes displayed above, the additional two vacant residences that <br />were not occupied during the traffic data collection period would generate an additional 19 daily <br />vehicle trips per the ITE rate, or approximately 9 ADT trips per derived rate from collected <br />traffic count data on Capital Drive. <br />3.3 Construction Traffic <br />During the neighborhood meeting, a question was raised about construction traffic. <br />Construction traffic is considered a temporary traffic condition, with a limited finite duration. <br />The level of construction traffic that will result from the proposed development on the site will <br />© Branch Engineering, Inc. <br />Page 1 10 <br />