Some cars are not registered to be taxis but still operate as them.
The movie demonstrates how armored cars can still operate under extreme stress.
The law also acknowledges that the operator will not need to pay attention while the car is operating itself.
The engine actually warms up more quickly once the car is operating, and will stay warm after stopping.
The car could operate in the forward direction only.
"You say the car had never operated by itself before ?"
Many cars and, especially, motorcycles operate at night without lights.
Because the cars operated on narrow streets, they were slower than most systems.
These cars were operating on the system's Desire route in the 1947 play and later movie of the same name.
This meant that cars were often operating far from their most efficient point.