Factories in the manufacturing industry and warehouses in the logistics and transport industries are often equipped with forklifts, trucks, AGVs (Automated Guided Vehicles), AMRs (Autonomous Manually Operated Robots) and other vehicles for transporting and handling goods. Construction sites in the construction industry also use cranes and other heavy equipment, as well as dump trucks and other vehicles. On each of these sites, vehicles and people travel in the same area, which can lead to a high risk of contact, often resulting in serious accidents.

For example, the following cases of accidents involving forklifts occur frequently (according to an accident survey by the Ministry of Health, Labour and Welfare).
The driver fails to notice a worker hidden by the load and crashes into him.
Crashes involving workers when changing direction
A vehicle jumps out of a blind spot in a corridor and hits a passing worker.
A worker is caught between a swerving vehicle and a wall.
In particular, more than 60% of all workplace accidents caused by forklifts are caused by being caught in or caught in the middle of a vehicle or by being struck by a forklift truck, and nearly half of these accidents result in death.

These accidents cause a wide range of damage, including medical treatment for employees, compensation for absence from work, repairs to vehicles and equipment, as well as losses due to stoppages in production. In addition, corporate compliance can be called into question. Preventing contact accidents is becoming increasingly important.

A number of measures are in place at workplaces to prevent contact between vehicles and people.
One of these is the deployment of surveillance personnel. One of these is the deployment of monitors, who are stationed inside factories and warehouses to control traffic. However, factories and construction sites are often large enough that it is not practical to have people in every part of the site at all times.

Another safety measure is the "separation of people and vehicles", which separates the operating areas of vehicles and people. However, it is not possible to prevent contact completely, as people may need to cross aisles for vehicles, or transport vehicles may intrude into people's working areas.

Increasingly, sensor-based detection systems are being introduced. These are systems where a sensor (detector) is fitted to a vehicle and when a worker with a tag approaches, the sensor detects and alerts the operator with an alarm. The sensors are expensive and improve the effectiveness of contact prevention, but the cost of installing the equipment, including sensors on all vehicles and tags for people, is an issue.