Expanded Access to East County


Metal frames for bus shelters at new Antioch BART station


Grading to prepare for new Highway 4 lanes


Retaining wall construction


Processing the old roadway for recycling


Metal frame for bus shelters at new Antioch BART station


Drilling in soil nails to stabilize the ground under the new highway lanes


Constructing new Highway 4 lanes

The fifth phase of the Highway 4 Corridor Projects, the Hillcrest Avenue segment signified the highly-anticipated conclusion of construction on the main project corridor, ending in the city of Antioch. Additionally, the lane openings at Hillcrest Avenue marked a significant milestone: the official opening of all westbound highway lanes for the Highway 4 Corridor Projects.

The Hillcrest Avenue segment also required the most detailed construction work for the new BART station, including construction of a maintenance tunnel, the median platform foundation, the pedestrian overcrossing, and the entry house. A unique 145-foot-long and 13-foot-wide overcrossing was constructed to ensure the safe passage of pedestrians over the expanded four-lane westbound side of Highway 4 to the future BART platform at Hillcrest Avenue. Usage of a larger-than-life crane, as captured in the images above, was required to lift the platform into place — indeed a monumental sight to behold.

To bring regional connectivity further out into East County at a lower cost, the BART extension is being constructed with a new kind of train for the system, one that is 60% less costly to build than traditional BART trains. Additionally, thanks to leading-edge technology to be installed along the corridor, transit riders will enjoy more seamless connections between bus and BART.

“CCTA is pleased to have provided increased capacity on these segments of Highway 4 making it easier for residents of East County to spend more time with family and friends and less time on the highway.”
– Randy Iwasaki, Executive Director, Contra Costa Transportation Authority


timeline iconTimeline: March 2013 – June 2016
segment iconSegment: Hillcrest Avenue to Highway 4 / Highway 160 Connector Ramps
mileage iconNew lane miles added: 7.04
investment iconCapital investment: $56.1 million
contractor iconContractor: Joint venture between Bay Cities Paving & Grading, Concord, CA and C.C. Myers, Inc., Rancho Cordova, CA

Key Enhancements

  • Widened Highway 4 from two to four lanes including a High-Occupancy Vehicle lane in the eastbound and westbound directions
  • Reconstructed the Hillcrest Avenue Interchange to provide additional local street capacity, upgraded signalized intersections, an additional westbound loop on-ramp, and ramp metering capabilities
  • Constructed the BART Pedestrian Overcrossing, Station Platform, and Maintenance Tunnel at Hillcrest Avenue
  • Widened Slatten Ranch Road to provide additional local street capacity and accommodate the future BART Station Parking Facilities
  • Constructed auxiliary lanes in the eastbound and westbound directions of Highway 4