Toyota has developed an unusual device that helps accelerate car testing after rain. Instead of complex systems, Japanese engineers opted for a simple solution — a huge roller made of sponge material, which is towed by a car and literally absorbs water from the asphalt.

The problem arose at the Higashi-Fuji Technical Center proving ground, where several engineering teams test automatic emergency braking systems and collision prevention systems. For these systems to work correctly, the surface must be completely dry, so after precipitation, specialists had to wait several hours for the road to dry naturally.

Because of this, tests were often postponed to weekends. According to Toyota, in 2023, employees of these departments worked on non-working days more than three times more often than specialists from other departments.

In search of a solution, engineers considered various options — industrial hair dryers, vacuum units, powerful blowers, and even designs based on car windshield wipers. An industrial vacuum cleaner turned out to be the most effective, but scaling it up to process the test track proved too expensive.

As a result, the team settled on a maximally simple design. The device is a roller about 2 meters wide, made of a special sponge. As it moves, it absorbs water, after which the liquid is squeezed out by a metal roller and collected in a 320-liter tank, which can be quickly emptied.

Before launching the production version, engineers created seven prototypes, gradually improving the design. Since March 2024, the device has been regularly used at the proving ground — usually once or twice a month, depending on weather conditions.