To help prevent further tragedies and help truck drivers reduce blind spots while operating their vehicles, the law in New York City and other cities having a population of one million or more must have a convex mirror on the front of the vehicle. The mirror shall be adjusted so the operator can see three feet above the road, one foot directly forward from the midpoint of the front of the vehicle and extends the full length of the front of the vehicle.
This law is in effect for any truck with a GVW of over 26,000 pounds. This law does however exclude cab over trucks.
To see DOT approved cross over mirrors, check them out here: