Car Counter.

The Fukuoka Prefecture Police have these car counters on all major roads in the prefecture and many smaller roads. They count the number of cars, the distance between cars and the speed. of each car.
They are linked to a central computer system in the prefecture police office in Fukuoka city. There are several police officers that constantly monitor the system and watch the live video feeds from the cameras they have located around Fukuoka city. They use the data to change the timing of traffic lights to easy traffic congestion.
They even have loud speakers that they use to chastise people. If you park your car on one of the main streets in Tenjin the police will be monitoring you by camera and one of them will turn on their microphone and tell you to move your car.

Bicycle Trip from Iizuka to Koishiwara-Hikosan-Kawasaki-Tagawa-Iizuka 29.