Patterson Pass Road Safety Improvement Project

Alameda County is a primary destination for regional and inter-regional traffic for goods movement and workforce commute travel between San Joaquin County and Alameda County. Interstate 580, the major transportation corridor in this region, routinely experiences extreme traffic congestion. In an effort to avoid these congested freeways, commuters continue to seek alternative routes along the rural roads. Patterson Pass Road is one of the most travelled rural roadways utilized as an alternate commuter route in lieu to I-580 between Livermore and Tracy (daily two-way traffic is about 3,700 vehicles per day). In addition, the roadway provides access to rural residential properties, ranches, and wind farms. Bicyclists also use the road for recreational rides. During non-commute times, cattle and other livestock are moved onto and/or across these roads. It is also common for local farmers and ranchers to move equipment from one field to another during planting season. The vehicles and equipment used for farm and ranch operations are often much larger than that which the single lanes on these narrow roads can comfortably accommodate. Patterson Pass Road has a narrow traveled way width, ranging from 13 feet to 20 feet, with almost no paved shoulders, and includes limited unpaved shoulders, making it difficult to for two-way traffic to pass safely and/or to exit the roadway if necessary. At mile marker 6.4, the roadway width was extremely narrow (approximately 15 feet wide). Because of the narrow pavement section of the roadway, there was little room to adequately accommodate traffic traveling in two directions. Passing slow-moving vehicles is prohibitively difficult due to the narrow pavement width. All of these factors contributed to head-on collisions, side-swipe collisions, and run-off-the-road accidents. The improvements included in this project will prevent these types of collisions, accommodate emergency vehicle access along the roadway, and provide adequate space for two-way vehicle passage. Additionally, the improvements will: • Accommodate bicycle travel on the corridor; • Accommodate safe access of enforcement officers and emergency responders; and • Preserve the rural character of the corridor. This project also includes drainage ditches to collect runoff from the roadway, and guardrails to protect errant vehicles from going over the steep slope. Pass Road Improvement Project, in the vicinity of mile marker 6.4, deserves recognition for accomplishing the goals of minimally widening the travel way width to safely accommodate two-way traffic and emergency vehicles, providing roadway drainage and enhancing roadway shoulders. There have been no collisions or run-off-the-road accidents since the project was opened to the public on September 24, 2015. These improvements have, therefore, improved safety for all roadway users, including bicyclists, while maintaining the rural characteristics of this roadway.