Idling Engines

Timothy Chui – Wednesday, January 09, 2008 – The Standard

Transport sector representatives yesterday told lawmakers the proposed ban on idling engines is impractical for their trade.

Packing the Legislative Council chamber in response to a public consultation over idling engines, more than 40 representatives said only allowing the first two vehicles at taxi and public light bus stands to keep their engines running would be unworkable as some minibus stands service multiple routes.

They also pointed out that the no-idling rule would mean taxis starting their engines nearly 30 to 40 times a day. Kowloon Taxi Owners Association chairman Yum Tai-ping said this would reduce battery life to one to two months from eight to 10 months.

Many taxi organizations also resented being included in the ban after having complied with calls to switch over to liquefied petroleum gas.

Taxi Operators Association chairman Leung Shiu-cheong warned that forcing taxis to switch off engines when it rains would be dangerous. Leung said without air-conditioning the windscreen would be clouded, and reduced visibility could pose risks when the driver takes off again.

China, Hong Kong and Macau Boundary Crossing Bus Association secretary-general Chan Chun-yee said the windows of many coaches cannot be opened for circulation and that temperatures inside the cabins can reach 60 degrees Celsius in the summer without air-conditioning.

The transport representatives said a ban would hurt quality of service and undermine their trade because passengers and tourists would be reluctant to travel in a sweltering cabin.

Liberal Party lawmaker Howard Young sympathized with the representatives, but said: “We must all accept one point – if we want to improve air quality we have to accept a price … We shouldn’t just focus on cost. I understand if you have to start engines more often it would aggravate wear and tear, but we have to be prepared to pay a certain price and the level of comfort is the same.”

Exemptions were proposed for turbo-charged and air-brake trucks by Kowloon Truck Merchants Association chairman Leung Kun-kuen who said the two systems needed five minutes to idle before shutting down.

The Hong Kong Institute of Engineers joined calls for the ban to be adjusted for different engine types, but it added that the intentions of the bill could also be served by raising the excessively low temperatures inside franchised buses.

Annelise Connell, a spokeswoman for Mini Spotters, a group of activists pushing for fuel efficiency, gave six examples of police not enforcing existing laws and expressed the hope that any law aimed at reducing idling engines would have enough resources for enforcement.

Conservancy Association director Hung Wing- tat said most cases of idling engines by taxis, buses and coaches occurred in urban business areas with tall buildings and poor ventilation. This would compound roadside pollution, Hung said.

The environmental affairs panel decided to extend its hearing of public views to next Wednesday.

Saturday November 3 2007

Chester Yung SCMP

Tell us what good forcing engine switch-off will do, say experts

Scientists and engineers said the proposal to ban idling vehicle engines left unanswered key questions about the extent to which it would reduce air pollution. They urged the government to provide more data to justify the initiative.

‘What is the reduction in emissions after the ban? What is the improvement to air quality? These are the most essential questions and the government still owes us the answers in the consultation paper,’ said Alexis Lau Kai-hon, an atmospheric scientist at the University of Science and Technology.

Professor Lau said the government should be able to release precise calculations of the expected reductions in emissions of sulfur dioxide, carbon monoxide, nitrogen oxides and respirable suspended particulates. ‘I can’t judge whether it is a feel-good policy or an effective tool when these questions are still unanswered,’ he said.

Lo Kok-keung, of Polytechnic University’s mechanical engineering department, said the ban could improve roadside air quality but the information released lacked details.

‘Perhaps the government is still unable to come up with a rough estimate and that’s why it hasn’t put it in the consultation paper,’ Mr Lo said.

He estimated the pollutant emissions in busy districts such as Causeway Bay and Mong Kok could drop by 10 per cent if a ban was implemented.

In the consultation paper, the government compares the emissions of vehicles while running and when stationary with engines idling.

An idling diesel-engined public light bus emits about half the pollutants of one in motion. Cars running on petrol emit almost as much carbon monoxide and hydrocarbons when their engines are idling as when they are in motion.

The government admits emissions from idling engines are ‘small in quantity as compared to emissions from the entire vehicle fleet’, but says they cause air pollution and noise nuisance to nearby pedestrian and shops.

There are 550,000 vehicles on Hong Kong’s roads.

Fung Man-keung, lecturer in automotive engineering at the Hong Kong Institute of Vocational Education, said engines must be switched off for at least three minutes for there to be any effective reduction in the pollutants emitted.

‘According to overseas studies, if a driver keeps turning an engine on and off every two minutes, the time the engine is turned off has no significant impact on pollution and the action merely speeds up the deterioration of engine components,’ Mr Fung said.

Au-yeung Ming, a spokesman for the Motor Transport Workers General Union, which opposes a ban, said vehicle starter motors would wear out much more quickly if the proposal became law.

He estimates the lifespan of a starter motor would be shortened by two years, to five years.

‘If we keep switching the engine on and off while waiting in a long queue, we will only emit more pollutants,’ Mr Au-Yeung said.

Pollution hazard

Vehicles are the second-largest source of air pollution in Hong Kong, contributing to 25% of respirable suspended particulates, 25% of nitrogen oxides and 15% of carbon dioxide

While idling engines do not contribute as much as those in motion, the white paper recognises the problems they cause at ground level in congested areas, and the growing number of complaints

Exemptions from the ban include:

Vehicles which stop at the roadside to let passengers board or alight; the first two taxis or public light buses at a stand; vehicles remaining motionless because of traffic conditions such as traffic congestion, security vehicles