Shiloh Road from Rimrock Road to Grand Avenue will closed from 9 a.m. Monday to 5 p.m. Saturday, July 28, while Edward T. Copps Construction does preparation work for a bike-pedestrian underpass.
The 10-foot-wide tunnel will pass under Shiloh Road about where Colton Boulevard would intersect with Shiloh, if Colton extended that far west. The tunnel is intended to be a link in future segments of the BikeNet trail system and will serve as a school crossing for students attending nearby Arrowhead Elementary.
Scott Walker, a transportation planner with the City-County Planning Department, said the tunnel is being installed now before the scheduled widening and reconstruction of Shiloh Road.
This portion of the project will involve installing a culvert to relocate a portion of the Big Ditch, with flows under Shiloh near Colton. Tim Pirtz of Engineering Inc. said the tunnel will be built about where the ditch is now, so the ditch has to be moved south to make way for the tunnel.
The project, which will cost about $500,000, is being paid for through a combination of federal transportation grants and gas-tax proceeds.
Pirtz said the tunnel itself will be installed in two or three weeks and will involve a closure of longer than a week. The 130-foot-long tunnel will be similar to the bike-pedestrian tunnel constructed several years ago under Yellowstone River Road.
In addition to the tunnel, the construction company will be installing concrete approaches to either side of the tunnel, running about 300 feet east and west of the center line on Shiloh.
Of the half-million-dollar price tag, Pirtz said, the ditch culvert will cost $97,000 and the bike tunnel will cost about $109,000. The rest of the money will be spent on the approaches, retaining walls, utility realignment, guardrails and stairs.