The operation of a motor vehicle under the trying conditions of highway traffic today demands that the driver exercise constant vigilance and care, that he possess normal reactions, responses and judgment and that he be not so physically or mentally disabled as to be unable at any given time to respond to unusual situations. The use of any lower standard by any particular driver is a potential menace to the public. Indeed, most of the appalling present day traffic toll is attributed by some to such failure of the human factor.
Much consideration has been given by private citizens and agencies, by public officials and legislative bodies and by committees to the problem of highway safety. The human factor has not been overlooked; attempted means of control have been adopted, but unfortunately there are still almost countless instances of failure. All the states in the Union but three appear now