I actually would offer to switch, but that's a personal thing. I live in they city, and my run district is 190 square miles. There are a lot of guys out here that would know most of the roads better than I do, and can also drive much better in drifting snow than I can. I probably won't do more than 25 sometimes, but I know the guys who have been out here longer than I have been alive might still be comfortable at 35 or 45. And the difference between 25 and 45 is significant when the scene can very well be 40 miles from where the station is.
In any case, we have a rule where the driver is responsible for driving and "officer" or man in the passenger's seat is responsible for everything else. If the passenger suggests a change of drivers, it's the driver's call whether or not to change. Rank does not matter here, hence why "officer" is in quotes.