Appendix H - Transportation Supporting Information COMBINED

Transportation Impact Study for Hidden Canyon Residences & Preserve March 2023 Page | 35 4.5 SITE ACCESS & STOPPING SIGHT DISTANCE This section analyzes site access for vehicles, pedestrians and bicycles based on the proposed site plan presented on Figures 2, 2b and 2c and Appendix A. Main Access via Proposed Street B: This proposed roadway is forecast to have 21 a.m. peak hour vehicle trips and 29 p.m. peak hour vehicle trips traveling to/from lots 1 to 28. Most traffic is expected to travel to and from the east based on existing traffic patterns. The speed limit on Dublin Canyon Road changes at Street B. To the west, the speed limit is 55 mph; to the east, the limit is 45 mph. There is a 45-mph speed limit sign and radar feedback sign (giving eastbound motorists their speeds), at the site of the future street. Traffic approaching from the west should be legally traveling 55 mph. For traffic exiting the site from this driveway, the safe stopping distance for eastbound traffic is 500 feet. (If the available sight distance exceeds the stopping sight distance, the approaching vehicle can safely stop before reaching the vehicle exiting the site.) The clear sight distance to the west is 700 feet, which is adequate. From the east, westbound traffic is in a 45-mph speed zone with a safe stopping distance of 360 feet. The available sight distance to the east is greater than 1,000 feet, which is adequate. The design for this driveway includes a proposed short westbound left turn lane of about 75 feet and a transition distance, also of approximately 75 feet. This is a part of two back-to-back painted left turn lanes; the other direction serves Canyon Creek Circle. The dimensions of the existing eastbound left turn lane into Canyon Creek Circle are slightly greater than that proposed for Hidden Canyon. The back-to-back left turn lanes serve more traffic for Hidden Canyon than Canyon Creek. However, because these will be painted lanes, traffic operations allow motorists some leeway in their travel paths; thus TJKM judges these two intersections to be able to operate acceptably. Lots 29 and 30 Access: There are two existing single-family homes in this area that currently have two separate driveways accessing Dublin Canyon Road, about 275 feet east of the intersection with Canyon Meadows Drive. They will be replaced by two single-family homes that will share access to Dublin Canyon Road via the proposed EBRPD Access to the south. EBRPD Access: This location is expected to serve only three vehicle trips during the a.m. peak (one inbound vehicle trip to the proposed park that is attributable to the project, and two existing outbound trips that would be relocated from the existing Lot 29/30 residences), and 27 p.m. peak hour vehicle trips (including two existing inbound trips that would be diverted from Lots 29/30 to, and 25 project trips to/from the proposed park). Most project trips will be to and from the east. The safe stopping distance here is 360 feet. Currently, to the west, the visibility is clear for over 450 feet; to the east it is over 700 feet, both of which are adequate. In addition, short painted turn lanes are proposed; an eastbound right turn lane and a westbound left turn lane. The proposed right turn lane dimensions are adequate. There is an existing radar feedback sign for westbound traffic directly opposite the proposed EBRPD access, which would be acceptable with the project. Recommendation: TJKM recommends provision of a 100-foot long westbound left turn lane and a transition length of approximately 120 feet, given prevailing 45 mph speeds on Dublin Canyon Road, which is a greater dimension than shown on the proposed site plan.