VIADUCTgreene board member (and recent Cornerspotter) Leah Murphy sent us an email today to let us know there's been some damage done to the Reading Viaduct: "One of the three girders supporting the City Branch over Callowhill is visibly bent, and the catwalk and eastern railing are sagging down from the rail bed," Murphy wrote. She also thinks she knows how it happened and what can be done to ameliorate the problem.
It's not uncommon that trucks get stuck on Callowhill because they're too tall to make the clearance under the two trestles. Most of the time, truck drivers realize they're not going to make it once they get to 11th Street, and are forced to back up on Callowhill more than a block against traffic (a tricky job for a big rig!) because the elevated rail line also goes over 11th, which is one-way going north. Every now and then, a truck gets wedged under one of the two bridges, which has caused some damage over time. But this accident yesterday has definitely left a much more visible bruise—in fact much more than a bruise—on the City Branch Bridge.
I would expect a big part of the problem is signage. For one, the clearance signs are easy to miss. Also, as Callowhill is a one-way west-bound street, trucks first encounter the 9th Street Branch trestle, which has a 13'2" clearance sign posted (albeit at an angle that preferences views from north-bound traffic on 11th), but trucks who are able to pass underneath the 9th Street Branch then encounter the City Branch bridge 200 feet later, which only has a clearance of 12'11" (which is also posted). So, it's possible that trucks see the first clearance sign and think it applies to both. Who knows—maybe they think they can just squeak under.
These bridges were constructed at a time long before freight trucking became such a large part of transportation and logistics and at a time when trucks were nowhere near the heights they are now—modern-day freight trucks are typically around 13' to 13'6". The current day clearance standard for bridges constructed over the Interstate System is a minimum of 14 feet in urban areas.
I think this unfortunate accident points to the great need for improved truck signage in order to prevent further damage to the historic trestles. Highly visible signage should alert truck drivers to the upcoming bridge clearances before they get to 10th Street, which would give them the opportunity to choose a different route before it's too late.
Thanks so much, Leah, for reporting in!