The effort to widen California State Highway 4 will also include work along the median to make way for a future extension of the Bay Area Rapid Transit system. Courtesy of Caltrans
Expansion work along California State Highway 4, in eastern Contra Costa County, is improving one of the worst commutes in the United States.
January 21, 2014—The 130,000 commuters who travel along California State Highway 4 in eastern Contra Costa County—on their way to and from the San Francisco Bay Area for work—are among those who suffer one of the worst commutes in the United States, according to data published by Kirkland, Washington-based INRIX, Inc., a data analytics company that provides traffic information and driver services to transportation agencies and others worldwide. A new Highway 4 widening project that is expanding a 10 mi stretch of roadway will dramatically improve commute times, including those along the corridor ranked by INRIX as the 10th-worst commute in the nation in 2010, and 25th-worst in 2011.
The $1.3-billion highway-widening “megaproject” will expand the highway from four to eight lanes along a stretch that extends from Loveridge Road in Pittsburg to just west of State Route 160 in Antioch, from two to four lanes from Lone Tree Way to Balfour Road in Brentwood, and add missing connector ramps at the Highway 4 and State Route 160 interchange. Contained within the project cost, but considered a separate project, is a Bay Area Rapid Transit (BART) extension line from Pittsburg to Antioch.
The stretch of highway encompassed by the work extends through the foothills of the 3,849 ft high Mount Diablo, located along one side of the highway, and the Sacramento-San Joaquin River Delta region, located along the other.
The highway-widening project has been portioned into five major segments that are being constructed simultaneously and known by their cross streets: Loveridge Road, Somerville Road, Contra Loma Boulevard, Lone Tree Way, and Hillcrest Avenue. Last month the westbound lanes of the first two segments, Loveridge and Somerville, opened to traffic, joining those segments’ new eastbound lanes, which had opened last November.
Over the last two decades years, eastern Contra Costa County has grown to supply “a little less than ten percent of the housing needs for the Bay Area,” says Randell Iwasaki, P.E., the executive director of the Contra Costa Transportation Authority (CCTA), which is overseeing the highway-widening project with the California Department of Transportation (Caltrans).
“These communities went from small, sleepy communities to large communities,” Iwasaki says. “But the infrastructure hasn’t stepped up.”
The megaproject will widen California State Highway 4 along a
10 mi stretch from Bay Point to Antioch, near San Francisco,
easing one of the worst commutes in the country. Courtesy of
Contra Costa Transportation Authority
In addition to doubling the number of available lanes, the project will modernize interchanges, improve the on- and off-ramps, and provide space within the highways’ medians for “eBART,” the east county rail extension of the BART system, according to Iwasaki. While the highway-widening project is anticipated to be complete by 2015, the eBART expansion is currently slated to open for service in late 2017.
“The project is not a traditional widening,” says Ross Chittenden, P.E., the deputy director of the CCTA. “It’s really reconstructing the complete facility out there—other than one structure that’s going to be widened, every square meter of concrete is being replaced.”
To undertake what is effectively a complete rebuild of the highway while maintaining full capacity during peak time travel hours involves a highly complex yet flexible design strategy, Iwasaki notes. “In lieu of just closing the whole corridor and rebuilding it, [this requires] having to build portions of the freeway, switching traffic over, building crossovers, and then switching traffic to the other side.” And once that is done, the entire process has to be repeated once again, for the other side of the highway.
The initial design of the project sequencing was meant to have as little impact on traffic as possible. Chittenden notes, however, that CCTA is working in close partnership with the contractors for each segment, allowing them to make suggestions for additional improvements to the sequencing as opportunities arise.
As part of the highway-widening process, the profile of the highway will be raised by as much as 8 ft on soil berms, depending on location, according to Ivan Ramirez, P.E., a senior engineer at the CCTA.
The raised highway profile will resolve various issues along the route, according to CCTA. It will facilitate improved ingress and egress points, and for the Loveridge portion of the project, the raised profile will alleviate flooding issues caused by runoff from hillsides during heavy storms, as water rushes down Mount Diablo to its base at sea level, Chittenden says.
While the eBART and the Highway 4 widening are officially separate projects, the contractors for the highway-widening project are grading the median and installing the base and subbase layers for the eBART tracks, according Chittenden. “We’re also constructing the bridges that will accommodate the trains when there is a crossing over a creek or a local road,” Chittenden says. “We’re preparing the corridor for them, and they will come in later and lay the tracks and install all the systems work.”
The eBART system will be different than the main BART lines. The eBART line will operate multiple-unit trains that are slightly smaller than typical BART trains and run on diesel rather than electricity, according to the eBART fact sheet issued by the transit agency. The new eBART line will be slightly offset from the highway-widening project, extending further west to connect the current terminus of BART’s yellow line at Pittsburg/Bay Point with a new eBART station at Hillcrest Avenue, in Antioch. Once the system is complete, the journey between the two stations will take a mere 10 minutes.
In addition to the Highway 4 megaproject, CCTA also teamed with Caltrans on the Caldecott Tunnel Fourth Bore (See “Safe Passage” in the upcoming February 2014 issue of Civil Engineering,.) “These projects are administered by Caltrans,” Iwasaki says. “[But] the way the financial agreements are written, it’s not the state that’s on the hook for any overrun—it’s us.”
As a result, “we spend a lot of time actively managing these projects, using risk-management techniques and having our consultants make sure that they watch the scope, the costs, the schedule,” Iwasaki says. “We’re constantly monitoring these things to deal with issues early so that they don’t become real problems later on.”
The CCTA and Caltrans approach is a successful one: “Currently we’re about 60 million dollars under the budget [on the highway project],” Chittenden says. “Some of those dollars have been used to reinvest in other projects, and we’re hanging on to a small amount of those dollars as a reserve, [but] overall we’re on schedule and significantly under the budget we declared for the project in 2007.”
If everything continues as planned, this will be the second Caltrans and CCTA megaproject in two years, the other being Caldecott, that comes in on time and under budget, Chittenden says. “You don’t read about that every day.”
The Oakland-based Metropolitan Transportation Commission, the Sacramento-based California Transportation Commission, and the Washington, D.C.-based Federal Highway Administration are also involved in the Highway 4 widening and the eBART expansion projects.
Berkeley-based contractor O. C. Jones and Sons, Inc., completed the Loveridge section of the Highway 4 widening project. Walnut Creek-based contractor R&L Brosamer, Inc. completed the Somerville segment.
The project’s final three segments—Contra Loma Boulevard, Lone Tree Way and Hillcrest Avenue—are being completed by a joint venture between CC Meyers, Inc. and Concord-based Bay Cities Paving and Grading, Inc.