10km to cross the road, thats nothing
I have completly forgotten which directions sit it was, but when I asked for walking directions from Newport-On-Tay to Dundee instead of a freezing, windy 2 mile walk across the Tay Road Bridge it directed the poor walker via Perth. This is a 75km distance, and by my reckoning if you really wanted to avoid walking the bridge paying a local with a boat to ferry you would be a lot more convenient and probably cheaper too.