Arch Rock Bypass 4.18
The Arch Rock Entrance Station’s location, vehicle arrival rate, topology, and throughput cause vehicles to backup between Arch Rock and El Portal. At busy times the queue of vehicles extends down to Parkline and onto Highway 140 in El Portal.
The backup creates a number of visitor safety and operational issues:
1. Vehicles must wait in an area with a high incident of rock fall.
2. Emergency vehicles must wait in line or drive in the opposite lane of traffic to bypass the queue.
3. Administrative vehicles including government, park partners, YARTS, and concession vehicles must wait in line greatly reducing operational efficiency of the park.
Options to mitigate some of these issues have been considered and/or attempted over the years:
1. Move the Arch Rock Entrance Station. This may be the best long term solution, but currently is not feasible.
2. Use traffic management staff to manage the outbound lane and allow priority vehicles to pass. This option has been considered, but because of the length of the backup, it is considered to be unsafe.
3. Hold inbound traffic at a location west of Arch Rock to prevent backups in the most active rock fall areas. This option has been implemented during the summer of 2017 near the Dog Rock slide area to reduce the risk of vehicles being hit by falling rock.
4. Meter inbound visitor vehicles outside of the park in a location where priority vehicles may safely bypass. This option has not been attempted, but is being considered as a possible short term pilot.
Metering inbound vehicles to Yosemite along Highway 140 in El Portal. Yosemite National Park proposes to meter eastbound traffic on Highway 140 in El Portal to mitigate the safety and operational issues caused by the backup of vehicles at the Arch Rock Entrance Station.
Visitor vehicles will be allowed to pass the metering location at a rate that does not overwhelm the entrance station thereby displacing the queue of waiting vehicles from just west of the Arch Rock Entrance Station to Highway 140. A suitable location to meter inbound vehicles is at the junction of Highway 140 and the El Portal Road in El Portal.
Metering eastbound vehicles at this location allows for safe bypass of priority vehicles via Foresta Road. Priority vehicles may include government, partner, public/mass transit, and commuter vehicles. The number of vehicles utilizing the bypass will on average be approximately 5% (verify) of the total vehicle volume.
