Kyodo News reports that the Japanese government is planning to take its “idling stop” campaign from buses and taxis and other commercial vehicles to the general car-owning population in an effort to save fuel and reduce greenhouse gas emissions.

The proposed idling-stop campaign is the low-tech version of a hybrid stop-start system: manually turning off the engine when the vehicle is stopped for more than a very short time in traffic or at an intersection.

Although vehicles equipped with automatic idling stop devices are on the increase (such as the hot-selling Toyota Vitz—earlier post), and the Japanese government extends subsidies to commercial firms which use such vehicles, there is no such incentive for private cars.

Automatic idling-stop (or stop-start) systems save a significant amount of fuel, especially in cities.

The Energy Conservation Center of Japan, affiliated with the Ministry of Economy, Trade and Industry, carried out a three-week test in the summer of 2002 using two cars of the same make and model—one with an automatic idling cut-off and the other without it.

On open roads between cities there was not much difference between the two vehicles in fuel-saving because stops were few, but even so, the vehicle with the idling-prevention device used 3.4% less gasoline that the other car. In cities, however, fuel consumption dropped 13.4%.

A center official said that since the saving on fuel was large, “Operators of buses running on regular routes in cities, those of home-delivery trucks, and taxi companies have begun to actively introduce the practice.”

However, impatient drivers do not like to turn off their engines at traffic light stops because they want to get off to a fast start when the lights change.

With improved efficiency in starters and batteries, turning off the engine for a short time poses almost no problem, but even so many drivers find it a heavy psychological burden to deliberately turn off the engine by using the key.

The idea of drivers shutting of their vehicles to spare the air is not new. The state of Oregon, for example, advises drivers to turn off their engines after more than 10 seconds of idling on Clean Air Action Days.

This sounds like it might be the first broad-based national initiative to undertake the practice—at least recently.