[Originally posted in a comment at http://www.westphillylocal.com/2013/10/11/a-woman-critically-injured-in-hit-and-run-accident-near-38th-and-spruce/.]
I'm not kidding. Road-level trolley tracks and cyclists simply do not mix. I've been in accidents due to tracks in Philadelphia and San Francisco -- the two cities I've lived in with tracks in the streets. Nearly every cyclist I know in Philadelphia has been in at least one minor accident involving tracks, and several have real horror stories. A friend broke several bones in her face due to a slip on the tracks just weeks ago.
But you're right. I may be overestimating in my "thousands of injuries" claim. Unfortunately, we don't have solid data around this issue to reason from. No one keeps track of the number of bicycle accidents caused by trolley tracks, and cycling accidents in general are sorely under-reported. According to the 2012 PennDot Crash Facts & Statistics [1], there were 1,369 total bicycle accidents in Pennsylvania. Considering the estimated 36