National Trails Highway at 19 Bridges

National Trails Highway at 19 Bridges

The San Bernardino County Department of Public Works (County), in coordination with the California Department of Transportation (Caltrans), proposes to replace nineteen (19) timber trestle bridges with concrete bridges on the National Trails Highway (NTH), formerly known as US Route 66. The project is located between the unincorporated communities of Ludlow and Essex in the County of San Bernardino. A summary of the existing bridges including their length, width, and locations is provided in the above table. The existing bridges were constructed circa 1930 and span over man-made ditches or "flash flood washes". The existing bridges vary in length but share similar construction components. The typical existing timber trestle bridges are composed of simply-supported timber stringer spans with a laminated timber deck supported on timber strutted abutments and bents consisting of timber piles. The bridges are approximately 28-feet wide with guardrails that are substandard. Due to the poor bridge conditions Caltrans has approved federal Highway Bridge Program (HBP) funds for their replacement. Through the years, the bridges have been modified by various maintenance and repair work with the intent of maintaining public safety and prolonging the service life of the bridges. The proposed replacements will resolve all the bridge deficiencies and will remove the bridges from the Eligible Bridge List (EBL). The 19 existing, two-lane timber bridges will be replaced with bridges designed to American Association of State Highway and Transportation Officials (AASHTO) standards for two-lane concrete bridges, guardrail, guardrail end treatments, and approaches. The existing soil is sandy and susceptible to scour, so pile extensions would be utilized at the piers and the abutment foundation would be designed for scour. The bridge barrier would be steel California ST-85 Bridge Rail painted white which is Manual for Assessing Safety Hardware (MASH) approved and best matches the existing railing. The bridge lengths would match the existing lengths if possible, but would be lengthened as needed to convey the storm flows. Each replacement bridge would accommodate two 12-foot-wide lanes, two 3-foot-wide shoulders and two 2-foot-wide railings. The vertical profile of the bridges will remain close to the existing profile except for those bridges locations in which it is determined that additional vertical clearance is required to provide sufficient water conveyance beneath the bridge. It is anticipated that any such necessary changes in vertical profiles would be 3 feet or less, with the elevation gradually conforming to the existing roadway elevations. The National Trails Highway is posted at a speed limit of 55 miles per hour, with all the bridges located on straight segments of the road. The alignment would remain unchanged; however, up to 800 feet of pavement improvements on either side of each bridge may be needed to conform to the existing roadway vertical profile. Grading within the existing channels around the bridges may be needed to ensure sufficient storm conveyance and drainage of the area. A temporary, parallel road (also known as a “shoo-fly”) would be constructed at each bridge location to accommodate through-traffic during construction. Construction of each bridge replacement is expected to be completed in one season, limiting the time the detour would be in place to one season as well. Based on weather conditions and construction activities, it is possible that there could be intermittent closures of the temporary parallel road. Permanent acquisition of right-of-way is not anticipated; however, temporary construction easements may be needed to accommodate construction of the temporary detour routes. There is one existing utility, a fiber optic telecommunication line, which may require relocation as part of this project. All utility relocations would be included within the defined limits of the Project area. Typical equipment for roadway construction would include heavy construction earthmoving equipment, dump trucks and pavers. Typical bridge construction equipment would include cranes, pile drivers, excavators, and concrete pumps. This project is funded with federal funds and compliance will be required through the California Department of Transportation (Caltrans) District 8 Office of Local Assistance. Caltrans is the lead agency for National Environmental Policy Act (NEPA) compliance. The County is the lead agency for California Environmental Quality Act (CEQA). Purpose: The purpose of the Project is to replace structurally deficient bridges in order to: - Enhance safety on National Trails Highway by proving new vehicular crossings for 19 bridges; -Provide a transportation facility consistent with County and Caltrans Standards, as well as local and regional plans. Need: The existing National Trails Highway Bridges are rated “Structurally Deficient” by Caltrans under Federal Highway Administration prescribed inspection criteria. Full replacement of the bridges is needed because the current structures do not meet structural design standards.

Essex

San Bernardino

Southern California, Unincorporated

California Air Resources Board (ARB), California Department of Conservation (DOC), California Department of Fish and Wildlife, Inland Deserts Region 6 (CDFW), California Department of Forestry and Fire Protection (CAL FIRE), California Department of Parks and Recreation, California Department of State Parks, Division of Boating and Waterways, California Department of Toxic Substances Control (DTSC), California Department of Transportation, District 8 (DOT), California Department of Transportation, Division of Aeronautics (DOT), California Department of Transportation, Division of Transportation Planning (DOT), California Department of Water Resources (DWR), California Governor's Office of Emergency Services (OES), California Highway Patrol (CHP), California Native American Heritage Commission (NAHC), California Natural Resources Agency, California Public Utilities Commission (CPUC), California Regional Water Quality Control Board, Colorado River Basin Region 7 (RWQCB), Office of Historic Preservation, State Water Resources Control Board, Division of Drinking Water

Transportation:Other (Bridge Replacement)

Transportation

Aesthetics, Air Quality, Biological Resources, Cultural Resources, Cumulative Effects, Drainage/Absorption, Flood Plain/Flooding, Geology/Soils, Hydrology/Water Quality, Noise, Public Services, Transportation, Tribal Cultural Resources, Utilities/Service Systems, Wildfire