They should be kept within the driver's reach at all times.
They're located wherever the driver decides to put them. The only matter of law applicable to this is in the case of hazmat loads, where the driver is required to keep them within reach at all times while operating the vehicle.
18 wheeler has the higher gross weight
on average you need to fuel an 18 wheeler once a day
You need to give a specific model before this can be answered.
18 wheeler
18 Wheeler - 1979 VG was released on: USA: July 1979
Andrew Wheeler was born on 1988-01-18.
Ernie Wheeler died on 1982-06-18.
Earle Wheeler died on 1975-12-18.
There's political lobbies centred around truck drivers, but no "18 wheeler gang", at least that I'm aware of.
Semi Truck oer 18 Wheeler (Eighteen Wheeler)
Charles K. Wheeler was born on 1863-04-18.