I drive my truck about once a week when I commute to the next town to visit my office. That will drop to zero work related trips per week when I commute on my bike. I think it's funny that my smallest vehicle [Bike Friday Tikit] has become my go to ride for 80% of all my trips and my largest most capable vehicle [Mazda B4000 4x4] sits idle most of the time.
I'm not car free yet and I think I'll keep my truck running as long as I can. Although I don't use it often I do enjoy being able to load up 4 friends + their gear so we can be in the mountains in 90mins. Without a truck a lot of outdoor recreation possibilities would be unfeasible as it's a full day's ride to the mountains on a loaded bike.
Gas prices here are up to $1.26/L [~$4.76/gal] and there doesn't seem to be an end in sight. Perhaps I'll change my tune when gas is over $2.00/L and stop driving entirely. The good news is I'm able to take care of all my essential transportation needs on foot, by bike or with public transport. All my driving trips are optional.