Next, we need tougher emissions tests for vehicles still on our roads

Bryan Suen says as old polluting vehicles are retired, Hong Kong should next tighten its emissions checks for those still on our roads

PUBLISHED : Friday, 21 February, 2014, 3:57am
UPDATED : Friday, 21 February, 2014, 3:57am

Starting this month, the service life span of all newly registered diesel commercial vehicles is limited to just 15 years. Coupled with its plan to phase out older diesel vehicles, the government is determined and committed to improve roadside air quality.

This policy is part of a raft of incentives to tackle roadside emissions and protect public health. The ex gratia payment scheme to phase out pre-Euro IV diesel commercial vehicles starts on March 1, and will see more than 80,000 such vehicles off our roads by 2020. Together with the catalytic converter replacement scheme for LPG vehicles and the introduction of a new air quality health index, the plan underlines the government's commendable determination to improve Hong Kong's air quality.

But, though it might seem like we are moving forward in developing a green transport sector, are these policies, in fact, sustainable? Have officials considered all ways to cut vehicle emissions? It seems obvious that the government doesn't yet have a comprehensive strategy.

Replacement is certainly the easiest and fastest way to reduce harmful roadside pollutants. Taking the most polluting diesel commercial vehicles off the streets by 2020 is an admirable goal, but what of the Euro IV or Euro V vehicles still in use, whose emission control systems can degrade over time? These supposedly more advanced emission control systems are excluded in the current replacement programme.

Thus, we need a comprehensive inspection and maintenance strategy to ensure emissions from vehicles in use are controlled in the long run. Without such action, taxpayers' money for the replacement exercise will be wasted as poorly maintained vehicles will continue to ply our roads.

Currently, all commercial vehicles have to undergo annual inspection tests before their licences are renewed, which is governed by the Transport Department. The tests mainly focus on roadworthiness. Emission tests were introduced in 1999 . But vehicles are tested only while at rest - either with the engine idling or, additionally, with the accelerator pressed down - which cannot reflect the actual emissions level on the road.

Only a small number of randomly selected diesel vehicles are required to perform a more stringent test that measures emissions when the vehicle is actually moving. The government should consider bringing in more stringent tests to raise inspection standards.

Mechanics are already expressing frustration that proper maintenance of new vehicles, with advanced emission-control systems, cannot be carried out due to a lack of information from manufacturers. As a result, vehicles are leaving these garages without the required maintenance, meaning they may still be generating excessive emissions . There is an urgent need for the government to collaborate with the industry and provide training on new vehicle repairs.

Developing a viable green transport system requires collaboration between the government, citizens, vehicle manufacturers and repairers. It is clear the government has more work to do on roadside emissions. A comprehensive strategy to improve vehicle inspection and maintenance should be its next step.

Bryan Suen is a research and project officer at Civic Exchange