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United States

I-10 Alabama Street Interchange Improvements

Delivering PSR-PDS, PA/ED and PS&E to Enhance Traffic Operations in San Bernardino County


When the San Bernardino County Transportation Authority (SBCTA) undertook an $11 million project to enhance traffic operation and alleviate traffic congestion on the I-10 highway, they proposed the widening of Alabama Street and the off-ramps from the I-10 to provide additional turn lanes. In addition to bringing shoulders, sidewalks and curb ramps up to current standards throughout this corridor, these improvements required creativity to maintain existing overhead utility poles while also ensuring that sidewalks meet current Americans with Disabilities Act (ADA) standards.


TRC prepared a Project Study and Project Development Report (PSR-PDS) two months ahead of schedule to expedite ground improvements. Our team provided traffic analysis to ensure that improvements to turn pockets could handle all forecasted queues with no impact on the adjacent through lanes. Additionally, the Project Approval/Environmental Document (PA/ED) and 35% of the Plans, Specification and Estimate (PS&E) were developed concurrently by overlapping several PA/ED activities with the PS&E.


The overlapping of PA/ED and PS&E activities allowed groundbreaking to occur as soon as possible, and the proposed improvements were delivered with zero impact on right-of-way utilities. In close collaboration with the resident engineer, SBCTA, and Caltrans District 8, our team was able to minimize changes during construction, resulting in the project’s overall construction falling within the engineer’s proposed contingency. The expedited delivery of this project in conjunction with coordination with several other ongoing projects, such as the widening of the I-10, brought construction to completion in May 2023.

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