940.6 Traffic Signal Spacing

Appropriate signal spacing is needed to preserve efficient traffic flow and progression on urban arterial roadways; for instance, a quarter- or half-mile spacing allows traffic signals to be effectively interconnected and synchronized. Adequate spacing will also tend to reduce rear-end collisions and “stop and go” driving that increases congestion, delay and air pollution. In urban areas, these guidelines were developed to allow for smooth operations given a 90-second total traffic signal cycle length.

Minimum spacing between traffic signals on public roads

Table 940.6 Minimum Guidelines

Roadway Classification	In Current and Projected Urban Areas	In Rural Areas
Major, Freeway	Traffic signals not allowed	Traffic signals not allowed
Major, Non-Freeway	½ mile (2,640 ft.) – 1 mile (5,280 ft.)	See note below*
Minor	¼ mile (1,320 ft.) - ½ mile (2,640 ft.)	See note below*
* Rural traffic signals are generally isolated signals rather than signals placed in a progression along a route. Signals are to be placed at least 5,280 ft. apart because of high rural operating speeds.