Traffic Congestion Information

The color and length of an arrow displayed on the car navigation screen tells the driver how congested the road is.

The determination of “Heavy Congestion,” “Light Congestion,” or “Smooth Traffic” varies depending on the type of road, such as an ordinary road or an expressway.
Degree of congestion Ordinary road Urban expressways
(e.g. the Shuto Expressway) 		Intercity expressways
(e.g. the Tomei Expressway)
Heavy Congestion less than 10km/h less than 20km/h less than 40km/h
Light Congestion 10km/h to 20km/h 20km/h to 40km/h 40km/h to 60km/h
Smooth Traffic more than 20km/h more than 40km/h more than 60km/h
  • The “Smooth Traffic” indicator is usually disabled in a car navigation system’s default settings. For more information, please refer to the user’s manual for your car navigation system.