§ 1685. All vehicles must stop or yield at certain railroad grade
crossings where a stop or yield sign is erected. The state
transportation commissioner, with respect to state highways, and local
authorities with respect to local streets within their jurisdiction,
with the approval of the state transportation commissioner are hereby
authorized to install a stop or yield sign at any highway-railroad
crossings within their respective jurisdictions.

The design and place and manner of installation of such signs shall
conform to the manual and specifications for a uniform system of traffic
control devices adopted by the state transportation commissioner.

Whenever any such crossing is so designated and a stop or yield sign
is installed, it shall be unlawful for the driver of any vehicle to fail
to stop or yield within fifty feet but not less than fifteen feet from
such railroad tracks before traversing such crossing. The failure to
erect, or the erection of, or failure to replace or maintain such signs
shall not be a basis for any action of negligence against a municipality
or the state nor a basis of a defense by a railroad in an action based
on negligence against a railroad.