T.Y. Lin International (TYLI) served as Prime Consultant for the Highway 4 Widening - Segment 3 Project (Segment 3) for the Contra Costa Transportation Authority (CCTA) in Contra Costa County, California. TYLI was responsible for project management, environmental coordination, community outreach, design development, agency coordination and interface, utility coordination and relocation, and right-of-way engineering and acquisition support.
Segment 3 widened six miles of Highway 4 from four lanes to eight lanes. The highway carries one high-occupancy vehicle (HOV) lane and three mixed-flow lanes in each direction, with auxiliary lanes added between interchanges. Multi-modal bridges were constructed in the median to accommodate mass transit.
Additionally, TYLI oversaw design and construction services that widened an overcrossing, replaced undercrossings, added new eBART underpasses, and built retaining walls and sound walls. Planning and design also included new traffic signals, signal modifications, temporary signals, emergency vehicle preemption, portable changeable message signs, the traffic operation system, street and safety lighting, and pedestrian undercrossing lighting.
- Extensive coordination was required with CCTA, the California Department of Transportation (Caltrans), and local cities.
- TYLI provided strategic decision-making assistance for risk identification and management.
- Plans, specifications, and estimates (PS&E) met all stakeholder requirements while maintaining project scope, schedule, and budget.
- TYLI’s value engineering strategies expedited design milestones and reduced construction costs.