We Specialize in Delivering Complex Highway and Interchange Projects

Mark Thomas has a deep understanding of the processes and design standards required to deliver projects on state-owned and operated highway systems. We are recognized as a premier interchange and highway design firm, known for our ability to develop innovative geometric concepts to enhance safety and connectivity.
We have a long history of delivering impactful highway projects, beginning with our groundbreaking work on the US 101 Widening project in Santa Clara County, CA in 1986. Since then, we have planned and/or delivered numerous highway mainline and interchange improvements. Our extensive experience working with state transportation agencies has fostered strong relationships with both headquarters and regional staff. We are well-versed in the applicable highway design manuals, project development procedures, and agency-specific guidelines that govern project delivery.
We’ve developed a strong understanding of how to navigate the challenges of project development and approvals. We use this knowledge to produce planning documents and designs with a high likelihood of approval, and we work proactively with agency staff to create practical, mutually beneficial solutions.
Project Types
- New Interchanges
- Interchange Improvements
- Freeway & Highway Widenings
- Auxiliary Lanes
- Express/Managed Lanes
- HOV Lanes
- Freeway-to-Freeway Connectors
- Under and Overcrossings
- Bus-on-Shoulder Facilities
- Storm Damage Repairs

Caltrans Expertise
Our In-Depth Knowledge of Caltrans Improves Project Delivery
Mark Thomas has planned and delivered more than 200 locally sponsored projects on Caltrans facilities, representing over $15 billion in improvements. Through this extensive experience, we’ve developed strong working relationships with both Caltrans Headquarters and District staff and have deep expertise in the agency’s delivery processes and design standards.
With decades of experience developing projects across the state, we understand how to navigate key challenges to help ensure designs meet approval requirements. Our familiarity with Caltrans’ design standards and procedures allows us to proactively address issues and streamline the path to approval.
We’ve worked with every Caltrans district, as well as headquarters staff, and use these established relationships to help expedite decision-making, reviews, approvals, and the successful delivery of on-system projects for local agencies.