TYLin served as Prime Consultant for the Highway 4 Widening - Segment 3 Project in Contra Costa County, California.
Designed for the Contra Costa Transportation Authority (CCTA) to reduce traffic congestion, 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. Multimodal bridges were constructed in the median to accommodate mass transit.
TYLin 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.
Additionally, TYLin oversaw design and construction services that widened an overcrossing, replaced undercrossings, added new eBART light-rail underpasses, and built retaining walls and sound walls.
Planning and design services 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.
- TYLin oversaw extensive coordination with CCTA, the California Department of Transportation (Caltrans), and local cities.
- Services included providing strategic decision-making assistance for risk identification and management.
- TYLin’s value engineering strategies expedited design milestones and reduced construction costs.
- Plans, specifications, and estimates (PS&E) met all stakeholder requirements while maintaining project scope, schedule, and budget.
Image credit: Blueprint22 Photography