It was a dark and rainy night and he was following his GPS which led him down a concrete road to a bridge that dropped off into a river

I think that might've hampered his ability to see well. Not sure how visible the drop off is in general, not to mention on a rainy night, so it could look like everything is fine and then the bridge just drops off to nothing, so it isn't necessarily a simple case of "should've stopped if he couldn't see" either.

In any case, even though the "issue" is undoubtedly his since he died and if you mean responsibility then of course everyone is responsible for their driving. I'm just saying that (imo obviously) there's other parties responsible here too. Municipality/landowners for not fixing, marking etc the bridge so this doesn't happen. Driver for their part in the actual driving and decision made during it. But also Maps for the routing and not fixing the map even though they were informed of the issue. Since we don't know the specifics it's impossible to say specifically how much each part contributed, but I'd say most of the responsibility is on the municipality.