I used to live in Peoria IL and there was a really old bridge there with this type of roadway surface, I rode there all the time with 27x1-1/4 tires. I never had a problem, but it was always a worrisome moment approaching the strange bend this bridge had in the middle of it! Weird to have a bend in a bridge... Never had a problem there, though, not even in winter when the river beneath it would steam and create frost on the metal grating. Seems like it would be slippery. but I never had problems.