The California Department of Transportation, using state and federal funding, proposes to rehabilitate State Route (SR) 89 through repaving activities, drainage improvements, and construction of appurtenant infrastructure. The project limits occur between post mile (PM) 0.0 and 21.1, in Siskiyou County.
Purpose
The purpose of this project is to reduce distressed lane miles, improve ride quality, minimize future maintenance and capital efforts/costs, reduce worker exposure, extend the useful pavement life for a minimum of 10 years, and improve safety and facility reliability for all modes for travel and goods movement. The project would restore the pavement, culverts, and TMS elements to good condition.
Need
The majority of pavement within the project limits exhibits various forms and levels of
distress, including cracking, rutting, and poor ride quality. This pavement condition requires a high level of maintenance activities and costs and will eventually need repairs beyond routine maintenance. In the 2029 delivery year, all lane miles will be in fair condition. Shoulders are nonstandard and do not allow for use by cyclists, who are forced to share the lane with vehicles. Some culverts within the project limits have deficiencies, including rusted inverts, displaced joints, collapsed pipes, or blockages resulting in poor or fair conditions. Other assets within the project limits, including
Traffic Management System elements, signs, and striping, are non-standard, do not meet current design guidance, are obsolete, or have a poor or fair condition.
Project implementation would include the following improvements:
Pavement
Overlay hot mix asphalt over the main roadway from edge of pavement to edge of
pavement
Overlay paved driveways and public road connections up to the existing right of way
or end of pavement with hot mix asphalt
Install 8-foot-wide shoulders, 3-foot shoulder backing, 4:1 fill slopes, and 2:1 cut
slopes on both sides of the highway between PMs 20.02 and 21.02. The new
impervious surface area is estimated at 1.94 acres.
Install shoulder backing to support edge of pavement
Perform pavement digouts at spot locations
Install centerline rumble strips along the length of the project and shoulder rumble
strips along the shoulder widening limits (PMs 20.02 to 21.02)
Signs and Delineation
Replace signs, pavement markers, and roadway delineators in accordance with
current standards.
Traffic Management System
Install traffic monitoring stations near the intersection of 43N19 Military Pass and
40N44 Middle Falls:
o Install four loops, two piezos, and one cabinet at PM 14.42. Work would
include minor trenching to connect to the proposed cabinet.
o Install two loops near PM 14.19.
Drainage
As part of the proposed project, 44 culverts occurring along the corridor would be rehabilitated through cut and cover and liner installation. Minor vegetation removal would be required. Temporary access roads would be constructed at PM 1.55, 5.24, 5.39, and 12.47 to facilitate the drainage improvements.
An additional three culverts (PM 1.22, 5.90, and 13.62), were evaluated and are
included in the environmental clearance. Due to a lack of funding, these culverts were not included in the scope. Should additional funds become available, or as part of a future maintenance effort, the culverts can be rehabilitated with minimal environmental review.
Disposal/Borrow Sites
Project implementation would include approximately seven acres of ground disturbance; the maximum excavation depth is estimated at 15 feet. Excess soil material and construction debris would become the property of the contractor. An existing disposal site for maintenance activities located at PM 1.5 (eastbound) would be expanded.
Stormwater Treatment Best Management Practices
The project is located within the Central Valley Regional Water Quality Control Board
(RWQCB). Permanent stormwater treatment best management practices (BMP) are
anticipated to be required by the RWQCB as the combined acreage for new impervious surfaces, not excluded from the threshold calculation, exceeds 10,000 square feet. New impervious surfaces are estimated at 1.94 acres. Additional stormwater runoff created from the new impervious surface would be treated within existing Caltrans right of way along the shoulder widening section (PM 20.02 to 21.02) utilizing Design Pollution Prevention Infiltration Areas, biostrips, and/or bioswales BMP strategies.
Staging
Staging activities would occur within Caltrans right-of-way at PMs 1.51 (westbound), 19.52 (eastbound), and 20.56 (eastbound).
Utilities
No utility conflicts are anticipated.
Right-of-Way
Caltrans would acquire temporary construction easements at various locations to conform driveways and to accommodate culvert installation. Encroachment permits would be acquired to conform public road connections. No permanent right-of-way take is anticipated.
Schedule
The work would be completed in two construction seasons and would require approximately 150 working days.
Permits
Based on the current scope of work, permits are anticipated to be required from the Army Corps of Engineers, California Department of Fish and Wildlife, and Central Valley Regional Water Quality Control Board.
Coordination/Consultation
Caltrans has performed a review of resource records and databases and consulted with applicable agencies and individuals. Consultation with tribes is ongoing and will continue through project completion.
