Yes there is a low bridge, but you can simply avoid it. When exiting Grand Island on the I190 take the exit to Buffalo Ave. This exit is actually on the bridge. DO NOT take the second exit on the right, but go straight to the traffic light, and then turn left under the I190 ( the bridge clearance is 15'+ ) then take the left on the Robert Moses Pkwy. This will take you down town Niagara Falls.At the round about take the first exit. Continue on this road till it ends (less than a half mile) turn left. On Rainbow which ends at the Rainbow Bridge.
If you want information on what to see or do let me know.
Bob