In a growing trend among local governments to assert their authority, prefectural governors and some municipal leaders in the Tokyo metropolitan area are inclined to take tougher measures than the state against diesel-powered vehicles.
The man leading the way is Tokyo Gov. Shintaro Ishihara, an outspoken novelist-cum-politician, who won the Tokyo Metropolitan Assembly's approval in December for an ordinance to reduce the volume of particulate matter -- a suspected carcinogen -- in the exhaust discharged by diesel-powered buses, trucks and other vehicles.
The key feature of the ordinance is a provision aimed at barring from the metropolitan area trucks and buses failing to meet emissions standards to be set by the city government.