Prisons can use buses, vans, cars or trucks for hostage transport, depending on the character of the need. For huge groups of prisoners, a van or bus is generally preferred. Workers will move the prisoners onto the vehicle and manage them during the transport. The prisoners may wear shackles and could be handcuffed to their seats, based on the nature of their violations and the objective of the transport.
Life is really simple, but we insist on making it complicated.