There is a bridge like that between Beaver Falls and New Brighton PA, only it crosses the river at an angle with the grating square to the riverbanks. Of course, the grating is angled to lead you into the oncoming lane. Guess it's better than leading you over the side.
Best thing to do is relax and only suggest to the bike where you want it to go. If traffic permits, try to time it so you cross alone. On the plus side, snow usually falls on through the grating and, even when coated with ice, it gives you some traction.
