Steel “I” beams are the go-to method for clear spanning bridge distances up to about 30 meters, just under 100 feet.
Because they must be rolled at the mill into a single length, they can difficult to transport on public roads.
A very long steel “I” visited the ClockTower briefly the other night, passing under our windows on Lincoln, then turning left up Bruckner Blvd.
They make a handy bench for lunch, too.
Image courtesy of the Bettmann Archive