Project Update: Interstate 80 Auxiliary Lanes

The Interstate 80 Auxiliary Lanes Project includes adding an auxiliary lane on eastbound I-80 and a fifth lane on westbound I-80. The first location is eastbound from Highway 65 to Rocklin Road. The second location is westbound from Douglas Boulevard to Riverside Avenue. (See Figure 1, 2 and 3)

Now you might be asking yourself, what is an auxiliary lane and why do we need this on Interstate 80?  Well, an auxiliary lane is a lane that is added between interchanges giving drivers more time to merge on or off of the freeway. Currently, Interstate 80 is not working to its full potential because of high traffic levels during peak commute hours. Today, congestion on westbound Interstate 80 during morning commute hours backs up from Douglas Boulevard toward Highway 65, while eastbound Interstate 80 east of Highway 65 is experiencing safety concerns with the high travel demands to Sierra College and other destinations.

Interstate 80 is one of the primary east-west interstates, serving as a transportation corridor for both passengers and freight. Recent growth in the south Placer region has increased traffic and demand on the road significantly. A 5th lane on I-80 westbound between Douglas Boulevard and Riverside Avenue would provide a great benefit to the area, resulting in five continuous lanes from Highway 65 to the Capital City Freeway.

An auxiliary lane on I-80 eastbound from Highway 65 to Rocklin Road would also improve safety in the area. There is currently frequent stop-and-go traffic due to cars getting on and off the freeway over short distances. An auxiliary lane could improve merging and reduce weaving by giving drivers more time to speed up and slow down.

PCTPA and its partners (the Cities of Rocklin and Roseville, County of Placer, Caltrans, and the Federal Highway Administration) have been diligently working to get this project “shovel-ready,” or to a point where construction can begin. The Interstate 80 Auxiliary Lanes Project received federal and state environmental approval in October 2016 and is now in final design, or the Plans, Specifications, and Estimates (PS&E) phase. 

While the final design phase has been funded by PCTPA, the construction phase of the project remains unfunded. Final design is scheduled to be complete by December 2019, and should funding become available, construction could start as early as 2020.

For more information on the I-80 Auxiliary Lanes project, visit: