SCH Number 2021040231

Project Info

Title

National Trails Highway at 10 Bridges Project; Draft Environmental Impact Report/Environmental Assessment and Draft Section 4(f) Evaluation

Description

The 10 bridges to be replaced along NTH are located mostly between Amboy Road and Kelbaker Road near the community of Amboy in San Bernardino County. The 10 bridges were constructed in 1930 and span over man-made ditches or “flash flood washes”. The existing bridges vary in length (40’ to 78’) but share similar construction components. The typical existing timber trestle bridges are composed of simply-supported timber stringer spans with a laminated timber deck with a concrete deck on it supported on timber strutted abutments and bents consisting of timber piles. The bridges are approximately 28 feet wide with guardrails that do not meet current AASHTO safety standards. According to Caltrans Structure Inventory and Appraisal Reports, nine (9) of the ten (10) existing bridges have a sufficiency rating less than 50 and are flagged “Structurally Deficient” (SD). The structural deficiency status is mainly due to a low superstructure rating attributable to damaged timber stringers.

2 documents in project