Abstract
A crude mathematical model is constructed to represent the flow of traffic in tunnels or other finite sections of highway on which passing is impossible. The main ingredients of the model are: (l) each car has a "desired speed which is considered to be a randera variable, (2) the actual speed of any car is the smaller of its own desired speed and the actual speed of the car ahead of it, (3) if the latter speed is the smaller, the trailing car maintains some fixed spacing behind its predecessor.