TOKYO -- A Japanese map platform developer funded by leading automakers will acquire an American peer affiliated with General Motors, seeking a stronger position for challenging Google and Chinese rivals in a vital area for self-driving cars.

Nikkei first reported that Dynamic Map Platform -- which counts Toyota Motor, Honda Motor, Nissan Motor, mapping company Zenrin and the public-private fund INCJ among its investors -- plans to buy Detroit-based Ushr in a deal estimated at nearly 20 billion yen ($181 million). The Tokyo-based Dynamic Map Platform announced the acquisition later on Wednesday.

Self-driving vehicles require highly accurate three-dimensional map data, which must be gathered using specially equipped cars. By joining forces, the two camps aim to improve their data-collection capabilities and provide an accurate, shareable platform. The goal is to present an alternative to Waymo, a Google group company that develops self-driving vehicles,which is racing for dominance in the field and could hinder development of new technology and services by rivals.

Waymo has been a trailblazer in autonomous driving, launching a self-driving taxi service in the U.S. state of Arizona last year. And the free and highly accurate Google Maps service has already supplanted built-in car navigation systems for many users, squeezing makers of such systems, like Japan's Pioneer.

Google could gain a similar grip on the market for map data used in autonomous vehicles. It has already partnered with automakers including Fiat Chrysler Automobiles, and the Nissan-Renault alliance is planning a tie-up with Waymo as well.

An image of Zenrin's high-definition 3D map. The technology is essential to developing self-driving technology. (Photo courtesy of Zenrin)

Dynamic Map Platform and Ushr plan to invest more than 10 billion yen in collecting road data in Japan and the U.S. Toyota, Honda, GM and other investors will use the data, and other automakers that want to avoid relying on Google will also be invited to take part.

Carmakers like Toyota and GM are sharing resources in areas where they can cooperate, focusing on fields with high added value, such as mobility services and analysis using artificial intelligence.

The battle for mapping dominance is taking place in other pats of the world as well. China's Baidu and Alibaba Group Holding have developed their own map platforms as part of a government push to promote self-driving technology. In Europe, BMW, Daimler and Volkswagen subsidiary Audi jointly acquired Nokia mapping unit Here in 2015.