Bidirectional traffic

[1] In the design and construction of tunnels, bidirectional traffic can markedly affect ventilation considerations.

[5] In a macroscopic theory proposed by Laval, the interaction between fast and slow vehicles conforms to the Newell kinematic wave model of moving bottlenecks.

[7] Entry to and exit from airports is always one-way traffic, as runways are chosen to allow aircraft to take off and land into the wind, to reduce ground speed.

[10] In the earliest days of railways in the United Kingdom, most lines were built double tracked because of the difficulty of coordinating operations in pre-telegraphy times.

In an analysis of head-on, rear-end, and lane-changing collisions based on the Simon-Gutowitz bidirectional traffic model, it was concluded that "the risk of collisions is important when the density of cars in one lane is small and ... the other lane['s] is high enough," and that "heavy vehicles cause an important reduction of traffic flow on the home lane and provoke an increase of the risk of car accident.