The standard prison van comes in a short, medium or long version. Three doors
separate the prisoner from the real world. The inside of the prison van is panelled
and the black windows are one way. Each prisoner is taken into the van, one
at a time and let into his own separate "box" cell, which has a plastic
moulded seat. The doors are controlled by a main switch board just inside the
first entrance kerbside door, by the prisoner guard who sits inside, however
each door has a separate lock and bolt which has to be manually locked and unlocked.
In the event of a serious accident there is a roof mounted escape hatch in each "cell" which is controlled by the same board as the inner doors. I would not like to be confined within the sweat box in any accident involving an overturned prison van, because you would be relying on others to release you who could well be too injured to do so. The prospect of the van entering water does not want to be contemplated too long, particularly if you are relying on electricity and others, for your survival!
There are rules concerning the length of time you can be transported in these vans, but should you have to go any great distance, the nearest jail to the point of stopping well be an overnight stop. If you are to be travelling a length of time, a pre-packed sandwich is provided. Smoking is of course forbidden, but everyone knows how to smuggle on board the kit and most guards ignore it, or smoke as well anyway.
The other travel times apart from transfer between police stations, court and jail, are when hospital visits or family bereavement journeys are made. These are usually made accompanied by prison officers, who in all probability know you and therefore the risks involved in your attempting to escape, or not. You will on these other journeys probably be travelling in a normal car, obviously to blend in as much as one can wearing handcuffs. Even in hospital, they will sit in view and you will be handcuffed to the bed! Do not get ill in prison, as the requisite section will explain.