Because in the state of Michigan has loop road ways otherwise known as a Michigan left - The state requires two exterior mirrors on motor vehicles at all times. Safety outside the vehicle is the main concern and ability of the operator view both sides of the motor vehicle continuously and the ability to merge back into traffic safely.
TWO (2): The rear view mirror and left side driver's mirror. If the vehicle has no rear window, then TWO outside mirrors are required.
2
not leass than two
Everyone in Michigan is required by law to be a vet, otherwise their ears are eaten by their mothers.
5
The Canadian Traffic and Safety Act dictates that a vehicle only needs the rearview mirror to be street-legal. Wing mirrors and any other mirrors on a vehicle are not actually required for legality. Source: I work for the Edmonton Police Force as a Traffic Cop.
Ask your advisor
In New York State:Model year 1968 and newer - must have a left outside mirror1967 and older - must have one mirror that is either an inside mirror or a left outside mirrorNote: Any vehicle that has a permanent obstruction of the view through the rear window (Example: a truck or van) must have both a left-side mirror and a right-side outside mirror.
They Do It with Mirrors has 187 pages.
2 or at least used to be-driver's door and windshield or both doors minimal if missing center
1 rear facing mirror, that is unobstructed and you can see 200 feet back through it
In Georgia, you can not tow a skier without an observer. So the answer is none.