Talk about a complete and fundamental misunderstanding of how the economy performs. You may not use a vehicle. EVERYTHING around you is brought to you by vehicles. If you think for a second that $400/bbl oil won't "bother you", that illusion will be shattered when you go down to get your latte and it cost $25. Of course, you will have long be out of work and unemployment will be at least 25% so you couldn't have afforded it in the first place. EVERY sector, every single one is affected by fuel prices and they will gladly pass those costs straight down to you.
The economy will be destroyed well before $400 a barrel oil.