Wandering the open wasteland seems like the perfect fit to have a horse or some type of mount to get around. Bethseda has had them in the TES games since Oblivion and I think they'd fit right in Fallout 4.
Vehicles I think could work as well depending on how they handle the survival elements.
Personally I'd like both to require some form of upkeep.
Mounts could require both Water and food, vehicles would require fuel and upkeep. With both able to take damage/breakdown.
I think if they required those kinds of things it'd really fit in, provide some nice money sinks and fit within the setting just fine.