District 4 Environmental Documents by County


I-580 and Interstate 205 Roadside Safety Improvement Project

I-580 Safety Lighting Project

I-680 HOV/express lanes project

I-880 Oakland-Alameda Access Project (OAAP)

Dublin Boulevard Extension Project RTPL 5432(019)


Marin State Route 1 (SR 1) Capital Preventive Maintenance (CAPM) Project

101 Irwin Creek Culvert Rehabilitation Project

U.S. 101 Storm Damage Repair Project


State Route 29 Bridge Rail Replacement Project

State Route 29 Sulphur Creek and York Creek Bridge Rail Replacement Project

State Route 29/State Route 221 Soscol Junction Improvement Project

State Route 128 Hopper Slough Bridge Replacement Project

San Francisco County

Better Market Street Project

San Mateo

State Route 1 Traffic Operational Systems Improvements Project

State Route 1/84 Structures and Scour Mitigation

Highway 101 Cordilleras Creek Bridge Replacement Project

Bridge Seismic Restoration Project: (Alpine Road Undercrossing Bridge, Sand Hill Road Overcrossing Bridges, and Interstate-280/Interstate-380 Separation Bridges)

State Route 1 Pescadero Creek Bridge Rails

Santa Clara

Newell Road Bridge Replacement Project

State Route 9 Saratoga Creek Bridge


State Route 12 Roadway Resurfacing, Restoration and Rehabilitation Project


1 Soldier Pile Wall Project

Sonoma 1 Culvert Rehabilitation Project – North

Sonoma 1 Culvert Rehabilitation Project – South

State Route 12 Capital Preventive Maintenance Project

Santa Rosa U.S. Highway 101 Bicycle and Pedestrian Overcrossing

District Wide Projects

State Route 37 Improvement

I-680 Express Lane Completion Project

Proposed Overview - As a major north-south freeway, I-680 is a heavily traveled corridor that connects the southern San Francisco Bay Area with Interstate 80 (I-80) and passes through Santa Clara, Alameda, Contra Costa and Solano counties. Within Contra Costa County, travelers experience congestion, traffic bottlenecks within the corridor, and increased travel times. To improve system continuity, congestion relief and operations, the project—part of CCTA’s INNOVATE 680 program—proposes to construct a northbound express lane from Livorna Road to State Route 242 (SR-242). It would also convert the existing northbound high-occupancy vehicle (HOV) lane that runs from SR-242 to the Benicia-Martinez Bridge Toll Plaza, to an express lane. The goal of the project is to complete the I-680 express lane network through Contra Costa County to increase travel speeds for those choosing to use the express lane.

The commenting period will be open from June 15, 2020 to July 29, 2020.