#UNDERPASS SIGN PLUS#
The tunnel’s vertical clearance should be at least 10 feet, and the width of the tunnel must be at least as wide as your trail, plus a 2-foot-wide shoulder on each side.
Most new tunnels are constructed with large, corrugated metal culverts or pre-cast concrete culverts.
Occasionally, the need arises for a new tunnel. Half of the tunnel was also improved to serve a future train line, making the Cal Park Hill Tunnel and the trail that it serves one of an increasing number of rail-with-trail projects around the country. Originally built in 1884 to transport trains hauling lumber and freight, the tunnel reopened in 2010 to carry bicyclists and pedestrians between San Rafael and Larkspur. The Cal Park Hill Tunnel in Marin County, Calif., is an excellent example of a converted railroad tunnel.
#UNDERPASS SIGN INSTALL#
Another option is to install strong, jail-like bars that prohibit entrance yet allow users to look into the tunnel.Įven if your tunnel is found to be structurally sound, make sure to schedule regular inspections to ensure that it remains safe for trail use. In the event that you need to seal your tunnel, you can do so with thick wood, steel or concrete. If the tunnel is found to be structurally deficient, and you are not immediately able to make repairs, it is best to close the tunnel temporarily and reroute the trail until repairs can be made. The engineer should inspect the structure and provide you with a written report of the tunnel’s condition, a list of what needs to be done to make it safe for trail use and a cost estimate for any repairs. To make sure your tunnel can be safely and successfully adapted for trail use, obtain a certified report from a structural engineer describing the current condition of the tunnel. These will describe significant structural features of the tunnel that are not apparent from visual inspection. If possible, locate the tunnel’s original engineering drawings. If a corridor includes a tunnel, the first step is to determine its structural soundness. Tunnels are among the most striking physical features of a trail and are often the most memorable aspects of a trail experience, while underpasses offer safe crossings of roads or other barriers where an at-grade crossing would be dangerous. However, a tunnel or underpass on a trail can also present challenging structural, design and management issues. Howard Tunnel on the York County Heritage Rail Trail - Photo CC Rob Carlson via Flickr
0 kommentar(er)
