Communications security is used to prevent unauthorized interceptors from accessing telecommunications. It also controls traffic flow security and emission security.

To regulate the flow of traffic.

Traffic moving the opposite direction of most other traffic

To control the flow of traffic during construction, it's best to have signs posted for drivers to know what is coming up the road. Next, have cones to guide the traffic and an flag person ready to signal which flow of traffic can move.

Pierre Dersin has written:

'Propagation of disturbances in traffic flow' -- subject(s): Traffic flow