An anonymous reader quotes a report from Nikkei: A joint venture in Japan will begin creating high-definition 3D 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 combination of high-resolution 3D 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 3D maps.