According to 11foot8.com, this train trestle is 100 years old, so it was built at a time when there were no standards for minimum clearance. They are not raising it because the Norfolk Southern Railroad doesn't care: it's their bridge and the only thing they want is to guarantee the safety of their trains. "As far as they are concerned, they solved that problem by installing the crash beam," 11foot8 says. Any potential solution-like raising the bridge or lowering the road-is too expensive to be worth it.
The city of Durham installed warning signs along the three blocks that precede the bridge, but the imbeciles still keep ramming into it once every month on average.
http://www.prochan.com/view?p=da1_1351183858 
