What is the location of the 11foot8 bridge?
201 Gregson St in Durham, NC (intersection with Peabody St)

Why is the bridge so low?
This train trestle is about 100 years old. At the time when it was built, there were no standards for minimum clearance.

How often do trucks crash into the bridge?
On average, about once a month a truck gets visibly damaged at the bridge. However, every day I see trucks that trip the overheight warning lights, stop and turn into the side street.

Why don’t they fix it?
Depends on who “they” are and on what “fix” means. The North Carolina Railroad Company owns the train trestle, and their concern is primarily with keeping the trains running and keeping them running safely. So their concern is mainly with reducing the impact of the truck crashes on the actual structure of the train trestle. As far as they are concerned, they solved that problem by installing the crash beam.
The city of Durham has installed “low clearance” signs on each of the 3 blocks leading up to the trestle (Gregson is a one-way road). There is an “overheight when flashing” sign with flashing lights that are triggered by vehicles that are too tall. Several blocks ahead of the trestle the speed limit is 25 MPH. The folks from the city planning department said that they made an effort to prevent accidents.
The North Carolina Dept. of Transportation maintains the road, but not the signage. I suspect they have much bigger problems to deal with statewide than this bridge.

Is the clearance signage accurate?
The clearance signage displays a maximum safe clearance – and yes, in that sense it is accurate. The actual clearance of the crash beam right in front of the trestle is 11 feet 10.8 inches, which gives it a 2.8 inch safety margin. The MUTCD allows for a maximum of 3 inches difference between the signage and the actual clearance.

Metric, please!
Would this situation be better if the signage were metric? Well … take a look at his website: 2m40.com (Warning: French. Metric)

For the convenience of our metric-only audience, here are the measurements we’re talking about in meters:
11foot8 (11 feet 8 inches) = 3.556 meters
11 feet 10.8 inches = 3.627 meters
Safety margin: 7.1 cm (at the crest of the road)

Can’t the road be lowered?
That would be prohibitively expensive because a sewer main runs just a few feet below the road bed. That sewer main also dates back about a hundred years and, again, at the time there were no real standards for minimum clearance for railroad underpasses.

Can’t the bridge be raised?
Here, too, the question is who would want to pay the millions of dollars to raise the tracks a couple of feet? To accomplish this, the grade of the tracks would have to changed on both sides of the trestle, probably for several miles. That would require rebuilding all trestles in Durham. And NS would have to shut down this busy track for months. I don’t think they are interested in that idea.

Is the signeage inadequate?
The signeage is pretty good. Large signs alert driver to the low clearance several blocks before the bridge. Overheight vehicles trip a light switch that turns on flashing warning lights.right at the bridge.

Should there be more signeage?
It’s hard to see how more “low-clearance” signs will significantly improve the situation. But maybe a different kind of signeage would get the driver’s attention.

Could they install a low-clearance bar?
A low clearance bar is a bar suspended by chains ahead of the bridge. Overheight vehicles hit that bar first and the noise alerts the driver to to the problem. I understand that this approach has been successful in other places, but it’s not practical here. There are many overheight trucks that have to be able to drive right up to the bridge and turn onto Peabody St. in order to deliver supplies to several restaurants. Making Peabody St inaccessible from Gregson St would make the restaurant owners and the delivery drivers very unhappy.

Why are they using yellow flashing lights?
Warning lights have to be yellow according to the NC traffic laws.

Are the drivers stupid?
No idea. They certainly seem distracted and the rental truck drivers are also probably inexperienced.

Will insurance cover the damages?
Most truck rental insurance policies specifically exclude overhead damage from coverage. However, a good auto insurance or liability insurance might pick up the tab. Check with your agent. Or even better – don’t hit the bridge!