Underpass projects must meet or exceed the minimum dimensions indicated in the following design chart.
|Rural-Suburban Design, Vertical Clearance||Urban Design, Vertical Clearance|
|Highway under Roadway Bridge||16-4||14-6|
|Highway under Railroad Bridge||16-4||14-6|
|Highway under Pedestrian Bridge||17-4||15-6 (a)|
|Highway under Sign Structure||17-4||15-6 (a)|
|Railroad under Roadway Bridge (b)||22-0||22-0|
(a) For replacement of skyway structures, the minimum clearance over traveled way is the existing structure clear height.
(b) Variances to the required minimum may be granted by the commissioner of transportation. That approval eliminates the need for a state-aid variance.
20 SR 1041; 23 SR 1455; L 1998 c 403 s 29; 24 SR 1885; 29 SR 449
October 15, 2007