Kumamoto's Car Society Cannot Be Solved by Roads — Transit's Downward Spiral and Planning Backward from Where People Live
Congestion is worsening in the Kumamoto urban area, where semiconductor industry is concentrating. The Kumamoto Urban Area Person Trip Survey shows the car's mode share rising from 64.4% to 67.3%, while the transit share fell from 5.9% to 5.2%. Adding roads does not clear congestion; in an expressway toll-free trial, traffic rose about 79%. This reads the downward spiral in which driver shortage leads to cuts, fewer riders, unprofitability, and withdrawal, and points to reconnecting where people live with transit by working backward, rather than widening roads.
TL;DR
- In the Kumamoto urban area, the car's mode share rose from 64.4% to 67.3%, while the public-transit share fell from 5.9% to 5.2%
- Adding roads does not clear congestion; in an expressway toll-free trial, traffic rose about 79%, showing that easier use draws more demand
- Transit has entered a downward spiral of driver shortage, cuts, fewer riders, unprofitability, and withdrawal, deepening car dependence further
In the Kumamoto urban area, the car's mode share rose from 64.4% to 67.3%, while the transit share fell from 5.9% to 5.2%. Adding roads does not clear congestion. In an expressway toll-free trial, lowering only the price raised traffic about 79%. Raise the ease of driving and demand rises. The way out is not wider roads but reconnecting where people live with public transit by working backward from transit.
What Is Happening
In Kumamoto, amid semiconductor concentration, congestion worsens; car dependence rose 64.4% to 67.3%, and road spending has not eased it
In the Kumamoto urban area, where semiconductor industry is concentrating, congestion is worsening. As FIRST-HAND Local reports from the field, life grows ever more dependent on the car. In the Kumamoto Urban Area Person Trip Survey, run by the city of Kumamoto and others, the share who use a car as their means of travel rose from 64.4% to 67.3%, while the public-transit share fell from 5.9% to 5.2%.
Measures have been taken. In the Kumamoto urban area, road improvements have gone on in the name of easing congestion. Still, congestion does not ease. Adding roads, voices from the field say, does not reduce congestion. The arrival of a semiconductor plant generated, all at once, demand exceeding the infrastructure that had been designed on a 20-year cycle.
Background & Context
Wider, easier roads draw more traffic, while transit enters a spiral of driver shortage, cuts, fewer riders, and withdrawal
That adding roads does not ease congestion is not only Kumamoto's story. Widen a road to make it flow, and even those who had held back begin to drive, so the traffic itself grows. Such moves pull demand in. In the national government's expressway toll-free trial, where only the price barrier was lowered, traffic on the target sections rose from 8,600 vehicles a day before the trial to 15,400, about 79% more. A toll-free scheme lowers the price; widening a road lowers the time it takes. The lever differs, but either way, raise the ease of driving and demand rises with it. So widening a road too, far from clearing congestion, can draw in new traffic.
Meanwhile, the public transit that should catch that demand is wasting away. Drivers run short, service is cut, routes are dropped. It grows inconvenient, riders fall away, operations turn unprofitable, and service is cut further. This downward spiral is turning in place after place. Bus drivers are projected to fall from about 116,000 in FY2021 to about 93,000 by FY2030, a shortfall of about 36,000. As the hands that carry shrink, transit shrinks further.
Reading the Structure
Some 2,500 transit blanks exist nationwide; the way out is not wider roads but planning where people live backward from transit
The more places spread where one cannot live without a car, the less transit can hold up. The national government calls areas that route buses and the like do not reach "transit blanks," and has acknowledged some 2,500 transit blanks nationwide. Congestion and transit blanks are the front and back of the same root, car dependence.
If so, the move is not to widen roads still further. Since easier use raises demand, widening becomes a chase. What is needed is to work backward from a form in which transit can hold up, and to reconnect homes with transit. That move has begun. According to the ministry, among the 527 cities that drew up a location-optimization plan for compact urban form, 424 municipalities also drew up a regional-transit plan, and began to think of where people live and of transit together.
Whether to keep adding homes where one cannot live without a car, or to redesign where people live from a form in which transit can hold up — the fork lies there. Each time a road is added, cars increase, transit wastes away, and transit blanks spread. To stop this chase calls for working backward, deciding where people live from transit rather than adding transit afterward. Congestion arises not from a shortage of roads but from a gap between how people live and how they move. Whether a region can keep its mobility turns on facing that gap and reassembling it head-on.
Further Reading
- 地域再生の戦略 「交通まちづくり」というアプローチ (A Strategy for Regional Revitalization: The "Transit Town-Making" Approach) (Kiyohito Utsunomiya, Chikuma Shinsho, 2015) — a case-based account of "transit town-making," rethinking car-dependent society and rebuilding towns around public transit. (In Japanese.)
References
Kumamoto Urban Area Person Trip Survey (Reiwa 5) — City of Kumamoto. City of Kumamoto
On the Status of the Expressway Toll-Free Social Experiment — Ministry of Land, Infrastructure, Transport and Tourism. Ministry of Land, Infrastructure, Transport and Tourism
The Current State and Challenges of the Bus Industry (submitted to an MLIT council) — Japan Bus Association. Ministry of Land, Infrastructure, Transport and Tourism, Council for Transport Policy
Bill to Amend the Act on Revitalization of Regional Public Transport (Resolving Transit Blanks) — Ministry of Land, Infrastructure, Transport and Tourism. Ministry of Land, Infrastructure, Transport and Tourism
Coordination of Location-Optimization Plans and Regional Transit Plans — Ministry of Land, Infrastructure, Transport and Tourism. Ministry of Land, Infrastructure, Transport and Tourism
