Under the fourth comprehensive national development plan, 14,000 km of Arterial high-standard highways and trunk roads are being constructed to improve access to tourist spots, airports, harbor and so forth, and to build comprehensive resilient road network.

In all major Japanese cities, ring roads are being constructed on a priority basis to provide urban infrastructure, alleviate traffic congestion, reduce CO2 emissions, and create a favorable living environment. In the congestion-plagued Tokyo Metropolitan area in particular, three ring roads (Metropolitan Inter-city Expressway, Gaikan Expressway and Central Circular Route) are under construction as part of a three-ring, nine-radii network. Moreover, to ease chronic congestion in urban centers caused by through traffic, the traffic capacity of roads is being expanded through the construction of bypasses and the widening of existing roads.

Today, 70% of 71 major airports and harbors in Japan are accessible from expressway interchanges within 10 minutes. To improve access, work is under way to construct access roads to major airports and harbors.

In 1966 National Expressway network plan was formally enacted for a 7,600 km national expressway network. In 1987 the plan was revised, as the fourth comprehensive national development plan, to extend the network to 14,000 km of Arterial high-standard highways. This plan aims at constructing national networks which are available from around the country within about one hour.

Average travel speed in downtown Tokyo is 16 km/h, which is half the national average. Driving time in traffic congestion of central Tokyo accounts for 60% of all driving time, which is 1.6 times of national average. In the metropolitan expressway of Japan, about 30 traffic accidents per day occur, and traffic congestion caused by these accidents accounts for about 10 % of all traffic congestion.

As of April 2011, completed sections of the high-grade expressways and trunk roads total 9,855 km (70% of the plan) and 95 % of all people in urban and rural areas can access the expressways and the trunk roads within about one hour.

Opening a part of Central Circular Route (from Route 3 Shibuya Line to Route 4 Shinjuku Line) in 2010 decreases congestion length by 30% and opening a part of Metropolitan Inter-city Expressway (from Hachioji JCT to Akiruno IC) in 2010 decreases congestion length by 40%.

70% of 71 major airports and harbors in Japan are accessible from expressway interchanges within 10 minutes.

Boarder Crossing, Congestion, Energy/Fuel, Environment, Infrastructure, Intercity, Intermodal, Interoperability, Expressways

Road Bureau, MLIT Japan