In an unusual move by the New York State Department of Transportation, all of the "speed limit" signs were replaced with "velocity limit" signs. Why are the devices in cars called speedometers and not velocitometers? a. What would such a sign look like? b. How could one travel faster than the old speed limit, without violating

In an unusual move by the New York State Department of Transportation, all of the "speed limit" signs were replaced with "velocity limit" signs

The devices are called as 'Speedometer' and not 'Velocity meters' because speedometer only gives the magnitude of the speed but not direction while velocity is vector quantity which will show speed as well as direction of the vehicle. Such signs could possibly look like ' Maximum legally permissible strength of velocity for forward progress is 30'  

Once can definitely travel faster using velocity meter than the old speed limit, it is because c=velocity includes displacement as it is vector. Hence it will allow the passengers to move in straight path without moving here and there on the road and it will help them reach their destination much faster than the old method without violating the rules.