Why do drivers drive through flooded roads ignoring the road closed signs

Some folks are rather optimistic about the depth of water their car can handle (or their driving skills).

Some folks know their car can handle the depth that road typically floods to.

Some folks hope the flood is beyond where they're going.

Some folks know damn well a road isn't still flooded but the signs are still up - often round here.

Again, locally to me, a main route might be 'closed' but if you know the back lanes theres a convoluted route using farm tracks and stupidly narrow lanes around whatever it is to get to where you want to be, but you'd need to be local to know that.

Some folks are, as humans always will be, just stupid.

Because people ignore 'road closed' signs all the time. Most of the time, there is absolutely no reason why you can't get to where you're going, so people have got into the habit of just ignoring the signs - until the day it really did mean 'closed ' . Then it's too late.

I can only imagine it's this - although as you say, why they'd try to drive through the water once they see it is a mystery.

The water company round here frequently "closes" the road in the village, although as there's only one long road going through the village they're rarely actually "closed" because of access. So I will drive through those (if I didn't I'd never get home).

Because they think they know best, and have no regard for why the road has been closed. Happens round here a lot and I have nosympathy for them

If you drive through floods you are an idiot. You have no idea what’s under the water, any amount of debris could stop the car regardless of if you think it can get through

you are also breaking the law if you go through a road that’s been formally closed

I think that a lot of people are really detatched from real life. They don't know how the car that they get in and drive works. They don't know what happens when you drive through deep water, therefore don't know why not to do it. We have all this information in our pockets at the touch of a button, but the level of real world knowledge has plummeted massively.

We have a road with a ford near me. There are signs as you approach from either side. There are depth markers in it which clearly show his deep it is.
After a few days of heavy rain, it's impassable. The roads toward it flood too.

It's perfectly possible to take another route which avoids it, which makes the drive around 5 minutes longer.

Yet every time we get heavy rain there'll be a few idiots who get stuck in it. And every time, people start saying the road should be "fixed" or there should be barriers, or how were they supposed to know it was actually deep.

Sometimes no-one comes and takes the flood signs down after the water has receded so people stop taking them seriously.

Also I think some people don't know what driving through a flood actually does to a car.

Signs don't always make clear exactly where the road is blocked. If the actual flood isn't visible from the point where the closure sign is, drivers trying to get to local destinations might proceed in hope that the flood is beyond their destination.

Of course, that doesn't explain why they continue once their wheels are getting wet!

Depends on the car and the driver...
one of my cars will go through 1/2 metre of water without issue - and modern versions can do a metre - another of my cars - small puddle would be all...
some people have cars with snorkels allowing them to drive through with water over the roof and the car carries on...
other people have totally inappropriate cars, but are not terribly clever drivers...

take your pick :)