Hunts Lane Grade Separation

The San Bernardino Associated Governments (SANBAG), in cooperation with the City of San Bernardino and the City of Colton, constructed a new grade separation between Hunts Lane and the Union Pacific Railroad tracks. Hunts Lane runs north / south and the railroad travels east / west through the project area. The railroad crossing at Hunts Lane was an at-grade, signalized crossing. The purpose of the grade separation was to eliminate the at-grade crossing, in order to enhance safety and relieve traffic congestion on Hunts Lane at the railroad crossing. The project limits on Hunts Lane extended from north of Oliver Holmes Road to south of Riverwood Street.

The new bridge elevates Hunts Lane over the UPRR tracks. The bridge (grade separation) was constructed on essentially the same alignment as Hunts Lane (before construction), and has four traffic lanes (two lanes in each direction), a sidewalk and a bike lane on each side. The bridge is consistent with Hunts Lane prior to construction, which was four lanes wide. The structure of the bridge is a single span, cast-in-place, post-tensioned, reinforced concrete box girder bridge, approximately 118 feet long and 74 feet wide. Total depth of the superstructure is 5 feet 3 inches. This structure has eight bays, bike lane, concrete sidewalk, concrete barrier and chain-link fence on both sides. The bridge foundation consists of two abutments with 6.48-inch cast-in-drilled holes (CIDH) piles at abutment 1 and 2.84-inch CIDH piles at abutment 2. Reinforced concrete approach slabs were constructed on both sides of the bridge.

CALTROP provided full construction management services, including source inspection. Our source inspection services included quality assurance inspection of precast concrete MSE wall panels. CALTROP’s Quality Assurance (QA) inspectors were available as needed to provide inspection, sampling and testing support, and structural steel and precast concrete fabrication at the source. QA inspectors inspected and reviewed all of the required documentation, and released the final product to the jobsite. CALTROP’s resident engineer on the project was also an experienced structural materials representative who coordinated inspections, conducted pre-fabrication meetings, and handled materials engineering issues and submittal reviews.

LOCATION: Colton and San Bernardino, CA
CLIENT: San Bernardino Associated Governments (SANBAG)
PROJECT VALUE: $20 million


  • Extensive Bridge and Roadway Construction
  • Retaining Wall Construction


  • Construction Management
  • Source Inspection