I prefer the open the door right away method.
The other way sounds good on paper, what with all of the pressure calculations etc., but not such a great method in practice. For one thing, you don't know how deep the water is, and how long it'll take to fill up the car before you can try the door.
You could end up on the bottom in some very deep water before the pressure equalizes enough to open the door.
I would think that it would be simple to add a safety device that works mechanically, using a float, or some other liquid sensing mechanism, that would trigger the valve on a compressed air tank, which in turn would drive a device into the window to shatter it, as soon as the water is like say shin high in the car.
That would eliminate the water pressure issue, so the door could be opened at any time.
The compressed air tank wouldn't have to be any more powerful than the ones they use for air bags.
Meaning, it wouldn't take up a lot of space, or be expensive.
I don't know if you remember, but we had a bridge collapse here a few years ago.
Here are some pics of that collapse.
I guess it's more important that corporations are allowed to dodge taxes so they can create jobs in China, than it is to force them to pay their share and then repair our infrastructure.
Fire the criminals on Capitol Hill.
They're not only ruining the economy, they're killing us.
Posted 2004 day(s) ago