The three-year Transit Only Lane Demonstration Project allows for South Bay Rapid buses (Route 225), operated by specially trained drivers and equipped with innovative technology, to perform Bus on Shoulder (BOS) operations along I-805 and SR 94 during peak travel times.

Rapid Bus

During heavy traffic congestion, South Bay Rapid buses can operate on selected freeway shoulders between Downtown San Diego and National City, helping bus drivers to bypass slow traffic and maintain transit schedules.  

The project includes the San Diego region’s first use of vehicle-to-infrastructure and advanced Intelligent Transportation System (ITS) technologies. Sensors embedded on these buses provide audio and visual alerts to the drivers regarding lane position and potential conflicts with other vehicles or obstructions along the corridor and shoulder.

Detailed performance monitoring will be conducted throughout the demonstration period to document on-time performance data, travel speeds, technology usage, enforcement issues, and rider/driver perceptions of the service. The data gathered will provide participating agencies with insight into future vehicle-to-infrastructure technology and operations.

After the project’s three-year demonstration period, the freeway shoulders will be restored to prior condition.  

Schedule and Budget

Highway construction improvements for the project will begin in mid-2020. The three-year demonstration project is anticipated to begin operations in early 2021.

Budget for the project is approximately $30.9 million (including $17 million for new Rapid buses). The project is funded by the Federal Transit Administration and TransNet, the regional half-cent sales tax for transportation administered by SANDAG.


Project Fact Sheet EnglishEn Español 

Project Map

Frequently Asked Questions

Charter Memo

Decision Document

Concept of Operations and User Needs

2005-2006 I-805/SR 52 Bus On Shoulder Demonstration project

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