TOKYO -- A joint venture in Japan will begin creating high-definition 3-D maps for self-driving cars in September as part of a government effort to have such vehicles on the road by 2020, when the Tokyo Summer Olympics will be held.

Tokyo-based Dynamic Map Planning, set up by Mitsubishi Electric, mapmaker Zenrin and nine automakers, will digitally chart the country's key expressways by driving a vehicle loaded with special surveying equipment. The data will be processed using computers designed for the creation of maps, which will be provided to automakers that invest in the startup.

As a first step, Dynamic Map Planning will make maps covering 300km of the country's main expressways.

The development of 3-D road maps is part of the Cabinet Office's Cross-ministerial Strategic Innovation Promotion Program and commissioned to Dynamic Map Planning.

Determining the accurate position of a vehicle in relation to the road is vital to commercializing self-driving cars. 3-D maps, based on survey data of road grades, structures, signage and other inputs, offer highly accurate data that can be used to determine positioning. For example, the maps will help to inform the vehicle to slow down in advance of a traffic light after a sharp turn and prevent traffic congestion by accelerating cars on slopes.

Although sensors can help cars navigate within lanes and prevent crashes with vehicles in front, recognition errors still present a problem. It is difficult for sensors to deal with complex road patterns, such as highway off ramps, because they cannot determine which is the right-turn lane among several road lanes.

Current vehicle navigation systems can display 3-D maps, however, they lack precision and data. In cases where elevated highways are located above a car, the navigation system often shows an incorrect location of the vehicle.

The combination of high-resolution 3-D maps and sensors will enable the accurate detection of which lane a car is in and the distance to junctions.

High-precision surveying technology is required to make the maps, so Mitsubishi Electric developed equipment that will be installed on a canvassing vehicle. GPS will track the location of the car on the map, and sensors designed to detect the inclination of the car will measure the road grades.

At the same time, data including the locations of road signs and traffic lights, as well as right- and left-turns and pedestrian crossings, will be collected using lasers. The survey data will be displayed as a collection of dots. Lines on the road, such as lanes, noise barriers and road signage, will be plotted on that image to faithfully re-create road conditions for 3-D maps.

U.S. search giant Google as well as German and Dutch companies are the leaders in developing 3-D maps. Japan hopes to speed up the creation of such maps at home to have leverage in setting their international standards.

Japan's main highways run a total of about 1.27 million kilometers including 30,000km of expressways. Cost-cutting measures and resource allocation will be the key issues in running the surveying vehicle, which is estimated to cost several tens of billions of yen (several hundreds of millions of dollars).

(Nikkei)