Dynamically managed shoulder running lanes offer a fast and affordable solution to crowded roadways
For years, the San Francisco Bay area’s Richmond-San Rafael Bridge was a little-used span. The bridge opened in 1956 with three lanes, but, because of the drought in 1977, one lane was closed so a pipeline could be placed across the span, bringing water from Contra Costa to Marin County. Once the pipeline was removed in 1978, the third lane was left as a shoulder because the bridge was so lightly traveled.
The bridge carries Interstate 580 as part of the Caltrans system, and in recent years became choked with traffic. The Bay Area Toll Authority, the agency that collects tolls on the bridge, approved restoration of the original third lane for peak-hour traffic use in 2014, tapping HNTB as designer of record.
The solution
HNTB designed a dynamically managed shoulder running lane – the first of its kind in California. It was delivered in April 2018 after just 15 months of construction, despite extensive road and lane realignments on both ends of the bridge.
The shoulder running lane is open daily from 2 to 7 p.m. and other periods of heavy congestion, with electronic message signs advising motorists whether the lane is open or closed. Access to the running lane during rush hour has relieved drivers from traffic backups and provided a more reliable commute.
Running lanes for congestion relief
Considering the traffic snarls that are common throughout all of California, shoulder running lanes should be seen as operational improvements to provide greater mobility. They offer key benefits:
• Faster delivery. Shoulder running lanes provide congestion relief on a much faster pace than a typical project delivery timeline allows. The I-580 Richmond-San Rafael Bridge Improvement Project, for example, was delivered in less than four years from notice to proceed to opening, including environmental clearance, final design and construction. To meet the demanding timeline, HNTB engaged stakeholders to build consensus on the project’s scope, lane operations and design elements. In the design phase, the team worked through potential problem areas. By the time design documents were handed to the contractor, approvals of construction methods were in place and construction could start immediately. To meet the demanding timeline, HNTB engaged stakeholders to build consensus on the project’s scope, lane operations and design elements. In the design phase, the team worked through potential problem areas. By the time design documents were handed to the contractor, approvals of construction methods were in place and construction could start immediately.
• Lower cost. Use of shoulder running lanes uses existing infrastructure at a fraction of the cost of building new. The Richmond-San Rafael Bridge project was delivered under a $27 million construction contract. Adding a new lane to the bridge would have required a multi-billion- dollar budget and a rebuild of the whole truss bridge.
• Access to best practices. Because no other shoulder running lane project previously had been undertaken in California, HNTB drew on its managed lane expertise in other states. Positive outcomes from this knowledge include design of Richmond-San Rafael Bridge gantries so each gantry can be managed individually. Among other advantages, this allows a lane to be closed if an accident occurs, but to be reopened downstream to permit traffic to flow freely beyond the accident location.
Chadi Chazbek
Managed Lanes Practice Lead
HNTB Corporation
ABOUT THE AUTHOR
Chazbek is a national expert on tolling and managed lanes with 22 years of domestic and international design and construction experience. He has had direct responsibility for projects ranging from feasibility studies to production of final design for multi-discipline, multi-million-dollar construction projects. Chazbek is very adept at defining project goals and issues, team building and assisting in the creation of public consensus for a project. Locally, he has managed the planning, environmental clearance and final design for six express/managed lanes corridors since 2009.
His industry involvement includes TRB managed lanes and IBTTA seminars and committee work.
Contact him at (510) 587-8629 or [email protected]