New Water-Permeable Road Surface in Tokyo

A new type of pavement that allows rainwater to permeate into the ground was used recently for the first time on Tokyo roads. A 62-meter-long stretch of "water-permeable" road was constructed in Setagaya Ward at the cost of about 6.5 million yen (about U.S.$54,000).

Fine gaps in the road surface let rainwater soak into the ground at the rate of 50 liters per square meter. Cities often suffer problems when downpours cause sewers to overflow and damage underground facilities such as shopping centers. This new type of road surface is expected to alleviate urban water disasters of this type, and may also mitigate the heat island effect, thanks to the effects of release of latent heat as water evaporates. Tokyo has already used this type of surface for sidewalks, but this is the first trial for roadways.

The new pavement costs 1.7 times more than the usual type, but further commercialization will help reduce its cost.



Posted: 2002/08/22 07:19:31 AM
Japanese version