Highway 49 Safety Audit

PCTPA partnered with Caltrans, other local agencies and the California Highway Patrol on the Highway 49 Safety Audit. The Highway 49 Safety Audit is a comprehensive evaluation of Highway 49 between Interstate 80 (I-80) in Auburn to McKnight Way in Grass Valley. The Safety Audit began in February 2020 with a three-day investigation of conditions along the roadway, traffic levels, speeds, collisions, and potential improvements to remedy issues.

Caltrans identified the following primary objectives for the study:

1. Identify safety-related improvements that could be installed within the very near term
2. Identify enhancements that could be added to planned projects in the corridor
3. Identify long term projects to improve corridor safety

This effort was a collaboration of several agencies: Caltrans (District 3), Federal Highway Administration (FHWA), California Highway Patrol (CHP), the Nevada County Transportation Commission (NCTC), the Placer County Transportation Planning Agency (PCTPA), Placer County Department of Public Works, the City of Auburn, and the Auburn City Fire Department. The safety audit was the combined effort of 22 individuals representing the entities listed above.

The Draft Safety Assessment Report was released on July 13, 2020 by Caltrans District 3. The report is available for download or can be viewed by clicking on the report to the right.

SR 49 is 22-miles from I-80 to La Barr Meadows Road and transitions from six-lane suburban street in Auburn to a four-lane rural highway in Placer County, to a rural two-lane highway in Nevada County, and to a four-lane freeway in Grass Valley. Given the variation along the route, the corridor was divided into the following four segments that have similar characteristics.

1. I-80 to Dry Creek Road – a four to six lane suburban arterial in Auburn and North Auburn
2. Dry Creek Road to Wolf Road/Combie Road – a four-lane rural highway with a continuous two-way left turn lane (striped median)
3. Wolf Road/Combie Road to Allison Ranch Road/La Barr Meadows Road – a two-lane highway with truck climbing lanes
4. Allison Ranch Road/La Barr Meadows Road to McKnight Way – a two-lane highway that transitions to a four-lane freeway at McKnight Way

SR 49 is a combination of suburban and rural areas that experience high traffic volumes and speeds, have frequent driveways for businesses or residents, and may have horizontal and vertical curves that may limit sight distance. The major focus on the study was to evaluate collision history and determine any trends in collisions. Overall the corridor tends to experience more collisions occur during the fall, possibly related to the slippery pavement during the first rain event after the dry summer months, increased traffic volumes at the start of the school year, the change from daylight savings to standard time, and seasonal animal migration. Additionally, more collisions occur on weekdays than on weekends and during the PM hours (noon to midnight) than the AM hours (midnight to noon).

Chapter 3 presents the collision history data for the corridor and Chapter 6 presents the recommended improvements to reduce collisions. The charts below summarize the collisions by type.

Over the last ten years (2010 to 2019), Caltrans has constructed the following projects on the study corridor. Additional projects are in the planning phases and are detailed in Chapter 5 of the Report. The cost and completion year of each project is provided.

• Installed shoulder and centerline rumble strips and six-inch striping from south of Michael Lane to the Bear River Bridge ($1.4 million, 2019)
• Extended northbound passing lane from Combie Road to Brewer Road ($1.4 million, 2010)
• Constructed right turn pocket at Brewer Road ($0.5 million, 2015)
• Constructed right turn pockets and shoulders at Carriage Road and Ladybird Drive ($2.2 million, 2014)
• Constructed northbound right turn lane and shoulder at Holcomb Drive/Cherry Creek Road ($0.8 million, 2014)
• Improved roadway curve superelevation near Mother Lode Road ($0.6 million, 2018)
• Installed emergency vehicle signal preemption at Wolf Road/Combie Road, Lime Kiln Road, and Alta Sierra Drive ($0.1 million, 2018)
• Widened SR 49 to five lanes from north of Alta Sierra Drive to south of Wellswood Way, constructed frontage roads, and installed a traffic signal at La Barr Meadows Road/Allison Ranch Road ($28.9 million, 2014)
• Constructed southbound right turn pocket at Smith Road ($0.5 million, 2016)
• Installed guardrail and rumble strips in Nevada County at various locations ($4.9 million, 2015)