Might not be a terrible idea, for any sea level east coast FReepers to keep at least enough gas in their car to get a hundred miles away from the coast on short notice, when everyone else is also trying to do the same.
Heck even a bicycle perhaps too. Just in case roads get blocked with traffic.
A bike can get quite a ways in 8 hours.
Another option...
Use this time, to think for a moment if you live in a lower elevation on the east coast - your most direct route to high ground.
Factor in, you’ll have 8 hours advance notice. Easy walk 3 miles an hour, that’s 20 miles in a pinch.
Most people could simply walk to safe ground, as long as they know ahead of time the nearest route uphill.
Anybody in Florida might do better to get to the roof of a sturdily-built apartment building than try to get to anything that looks like "high ground" in Florida, when everybody else is trying the same. A quick look at Google Earth shows that almost all of the Florida peninsula is under 100 feet in elevation, with at least half of Florida seeming to be under 50 feet.
General evacuation tip: Have a good state-level map in your car, along with a GPS, and avoid highways at all costs. As Katrina showed, highways quickly turn into slow-moving parking lots. If there's a street route to where you're going, use streets and minor roads rather than highways.
The bike isn’t a bad idea. There are few Eastern metropolises that could be evacuated in any reasonable time. It recently occurred to me the sensibility of knowing the nearest significant elevation at all time; It wouldn’t take that big of a wave to sweep all the way across Florida, amazingly enough; you can go clear from mid-state Atlantic coast to Gulf coast without getting higher than 20’.