- (a) The Department of Transportation, after consultation with the Department of the California Highway Patrol, the State Fire Marshal, and affected local agencies, and following a public hearing subject to Section 21109.5, may regulate the time when tank vehicles may travel through a tunnel on state highways.
- (b) In evaluating the use of a tunnel on a state highway, the Department of Transportation shall conduct a traffic and engineering survey which includes an analysis of the relative risks to public safety in determining the feasibility of reasonable alternative routes.
- (c) For the purposes of this section, a tunnel is a horizontal passage enclosed on the sides and top containing a roadway of a length of not less than 300 feet.
- (d) No prohibition or restriction adopted pursuant to this section shall be effective until appropriate signs have been posted giving notice thereof to drivers approaching the tunnel.