Why are Tokyo’s roads often congested despite the city’s highways and rail network?

Tokyo’s road congestion persists despite its extensive highway and rail networks due to several compounding factors:

• Infrastructure Lag: Road development has historically lagged behind Japan’s rapid economic progress. Construction is significantly hampered by the limited availability of land relative to the dense population.123
• High Vehicle Density: The region experiences an extremely high density of motor vehicles per unit area. Furthermore, trucks account for a much larger proportion of traffic compared to other major motorized nations, as the vast majority of domestic freight is transported by road.23
• Increased Automobile Usage: Many families now own multiple vehicles and are increasingly choosing to drive to destinations rather than relying solely on public transit.23
• Street Patterns: The complex and manifold surface street patterns in Japanese cities often impede the efficient flow of traffic, complicating the utility of the existing road network.23

While the city features a robust system of subways and commuter rail lines, these alternatives have not been sufficient to offset the sheer volume of cars, leaving the current road infrastructure woefully inadequate for the crush of traffic.42