Toyota and Weathernews have announced a partnership to improve weather forecast accuracy and driver safety.

The two companies will use data derived from Toyota’s connected vehicles, such as windshield wiper operations. The data will then be visualized as a map, showing where there are pockets of vehicles with running wipers. These areas of activity can be compared with data provided by Weathernews. Since precipitation does not always show up on radar, this will help Weathernews improve the accuracy of the data it has.

“It is said that the rate of accidents during rainy weather is four times that of sunny days, so the presence of precipitation has a large effect on safe driving for vehicles. However, raincloud radar, which is often used to detect and predict rainy areas, has the disadvantage of being unable to detect rain resulting from rainclouds in the lower layer of the troposphere (an altitude of 2 km or below) or small raindrops such as those that form during drizzles. In such cases, it has been difficult to accurately determine areas where it is raining.

“In the verification test that begins on November 1, as part of Toyota’s and Weathernews’ joint research initiatives, the wiper operating status of Toyota’s connected vehicles being driven in the designated regions is visualized as a map and compared with actual weather data. In past cases where low rainclouds produced rain that did not show up on raincloud radar in the Kanto area, rain was instead reported by users of the ‘Weathernews’ app. The user reports received matched closely with the areas where wipers were being operated, showing that wiper data can detect rain that cannot be detected using raincloud radar. We will also perform a detailed analysis of the relationship between the wiper data and weather data, and in addition to accurate detection of rainy areas, we plan to make efforts to estimate the strength of the precipitation based on the power at which the wipers are being operated, and consider using wiper data for weather forecasting.

“By using wiper data to accurately ascertain the conditions of roads and their surroundings, such as precipitation and actual precipitation strength, undetectable using radar, we aim to contribute to driver safety by issuing warnings to drivers according to the situation.”