Abrupt cutting in and aggressive tailgating have been the causes of serious incidents and accidents. Last year, the National Police Agency recorded more than 7,600 cases of tailgating across the nation.
A driver who frequently uses expressways says, "To be honest, it's frightening. I'm worried that it's not safe."
Another person says, "One day, the driver in front of us suddenly applied the brakes and it was scary because we had a child inside the car."
What's known as 'provocative driving' has led to serious accidents. This August, a hit-and-run in Kyoto left a woman with serious injuries.
Police arrested a 56-year-old man on suspicion of negligent driving resulting in injury.
Video from a drive recorder in a taxi passing the accident site showed a man in a car honking repeatedly and aggressively tailgating a bike in front of it, for about 150 meters.
One eyewitness says the driver of the car caused the accident by aggressively cutting in. Another says it started with a car honking at a traffic light.
Kyoto District Prosecutors indicted the man on charges of 'dangerous driving' resulting in injury, which can lead to heavier punishment than negligent driving resulting in injury. Provocative driving by aggressive tailgating is punishable under the Road Traffic Law.
Last year, the National Police Agency reported 7,625 cases of reckless driving involving aggressive tailgating. 87% of them occurred on expressways.
People buy dashboard cameras to protect themselves
More and more drivers are installing dashboard cameras in their vehicles as a safety measure.
Makers say they have received many inquiries. They say devices that can record the inside, rear and sides of a vehicle are especially popular.
Car stickers that say 'Drive Recorder' are also selling well.
A customer says, "If I become the target of a reckless driver, the data can be used as evidence. That's why I want to buy one."
Technology to help people stay calm is also being developed.
An automated system recognizes when a driver yells or has a stiff facial expression. A display shows 'anger' or 'concern', and an electronic voice asks, "Are you OK?"
Anger management specialist: Drivers feel like they're wearing armor
The Tokyo-based Japan Anger Management Association teaches drivers with trucking firms and taxi companies how to control their anger while on the road.
Association official Shunsuke Ando says people tend to feel like they're wearing armor when behind the wheel. He says they think they're being protected and are extremely powerful.
Ando says that drivers in such a state feel like they're being attacked or made fun of when a vehicle cuts them off or pressures them to drive faster. He says this easily escalates to anger.
He also says that people who are relatively young and have confidence in their driving tend to snap while on the road.
If you are cut off by another driver, he says it is important to wait at least 6 seconds before reacting. He advises drivers to take steps to control their emotions, such as talking to themselves to calm down and visualizing a thermometer that measures how angry they are.
Ando also advises on what to do when you're in a situation that could lead to trouble. He says the key is to move away from someone who you think is trying to harm you. He says if you cannot do so, consider calling the police from inside your car.
How to dodge problems
The operator of Japan's major road, the Tomei Expressway, is calling on drivers to move into neighboring lanes if they see vehicles making dangerous moves, such as getting extremely close to your car or pressuring you to speed up.
The operator says that if a nearby car tries to block your way, you should contact the police, instead of trying to deal with it on your own.