This may seem irrelevant, but it is not legal to drive without your shoes. Some people are still not sure why, because they do not see the bad side of it.

When it comes to UK they definitely won’t allow you to drive your car with your barefoot. Why is it forbidden? Well even though it does seem harmless, if you don’t wear your shoes while you are driving you are not able to operate the controls safely.

For example if you do so and your feet are vet, you might be putting yourself and of course the passengers and other people on the road at risk, because you are not able to drive your vehicle safely. That’s why it is not legal.

When you are not wearing shoes you don’t have the same braking force with bare feet as you do have with your shoes on.
Also inadequate shoes that are unsuitable for piloting a car are definitely flip-flops and high heels. 

When it comes to United States people there are little bit more flexible, so there it is allowed to drive barefoot.
There are no state or federal laws that prohibit driving a car without your shoes. This goes for cars, but if we are talking about motorcycles the situation is different.
Some states do require footwear, and this does not apply only to drivers, but it also applies to passengers.

In Alabama the law states “ No person shall operate or ride upon a motorcycle or motor-driven cycle unless he is wearing shoes. “
Good news for those who want to drive barefoot is that California allows that. They don’t recommend it for sure, but there is no law against it.