RE: Motorist Notification of Low Clearance

["William Lambert" <WLambert@xxxxxxxxxxxxxxx>]

Tom,

>From my perspective, you've probably done all that is reasonable and
then some.  What you're looking to do now is idiot proof the approach.
Generally, the low clearance railroad overpasses are also narrow, so you
might have reason to attach Type III object markers on the bridge
abutments.  Florescent sheeting might be considered as it improves
visibility in the day time, and since it is only available in higher
grade sheeting, it is also more visible at night.  Reflective material
could also be attached to the overhead beams as well.

As a last resort, you might have the railroad consider advance overhead
signs set at the same clearance as the bridge.  Obviously, you would
want to have the signs attached in a manner that would give if struck
(some sort of hinge mechanism) so you aren't liable for the damage to a
vehicle that should be there anyway.  That would give the physical
warning to an overheight vehicle that would be less costly to repair
than the bridge and would not require shutting down the rail line.

Good luck,
Bill Lambert

-----Original Message-----
From: owner-PW.Net@lists.unh.edu [mailto:owner-PW.Net@lists.unh.edu] On
Behalf Of Tom Willis
Sent: Monday, March 27, 2006 10:41 AM
To: Public Works Net
Subject: Motorist Notification of Low Clearance

To the Net:

We have an railroad overpass over a class V rural collector road that 
has a signed vertical clearance of 11.0 feet.  The actual clearance is 
about 8 inches higher, however we and the railroad are erring on being 
conservative.  During calendar year 2005, two trucks got stuck under the

bridge, one truck with a height of over 13 feet hit with such force that

it moved the cast iron bridge structure about 18 inches on it abuttments

and cost the railroad about $50,000 to repair.  The railroad was out of 
service for a week.   The approach to the overpass is signed according 
to MUTCD standards in that we have two W2-12 signs in each direction.  
One as one enters the road and another several hundred feet in advance 
of the overpass.  There is a flashing amber beacon in close proximity to

the final sign before one comes upon the overpass.   Following the 
second mishap, we reviewed the MUTCD for the signage requirements and 
found we were in compliance.

The railroad has approached us for ideas to enhance the warning of the 
low clearance to make it a bit more idiot proof.  One idea that we have 
is to paint the physical overpass a reflective yellow or yellow with 
black stripes and also put a sign with the vertical clearance directly 
on the overpass structure.  Currently the overpass is a grayish black.  
The area is not well lit so it is hard to see at night.

Our question is how have other communities tried to make their low 
clearance areas more visible and make the warning more noticable to 
further minimize the risk of having an oversized vehicle go under. 

Appreciate any ideas.

Thanks.

Tom Willis, PE
City Engineer
City of Rochester, NH
tom.willis@rochesternh.net