Civic Exchange’s New Publication Advocates a Stringent Inspection and Maintenance Programme for On-Road Diesel Commercial Vehicles

HONG KONG, 29 September 2014 – Independent public policy think-tank Civic Exchange launched a new report today entitled “Improving Hong Kong’s Emission Inspection Programme for On-road Diesel Commercial Vehicles”. This report explains the shortcomings of the existing Inspection and Maintenance (I/M) programme in Hong Kong and recommends ways to improve it based on international best practices and local circumstances.


Deteriorating roadside air quality and rising public health concern have prompted the HKSAR Government to undertake a series of measures for combating vehicular emissions. Three programmes costing a total of HK$11.5 billion have been launched since 2013, mainly focusing on liquefied petroleum gas (LPG) vehicles, pre-Euro IV diesel commercial vehicles (DVCs), and petrol vehicles. With these programmes, the entire vehicle fleet will become cleaner and be more diligently maintained. Yet, an effective emission inspection programme for on-road diesel commercial vehicles that includes roadside screening and enhanced annual inspection is still badly needed.

Diesel commercial vehicles and their emissions

In 2011, goods vehicles contributed 75% of particulate matter (PM10) and 44% of nitrogen oxides (NOX) emissions from all vehicles, which are disproportionately high relative to their numbers (18% of the vehicles). In light of this, the Government is spot-on to deal with the large emitter and provides a generous subsidy for pre-Euro IV DCV retirement and replacement, and emissions from DCVs are expected to be quickly reduced. However, emission reduction would only last if the emission control devices on these low-emission, replacement vehicles continue to function properly. An effective I/M programme designed for on-road DCVs is therefore essential.


Vehicular population





1,177 tonnes

32,660 tonnes

Private car




Goods vehicle












Franchised bus




Non-franchised bus




Public light bus




Private light bus




Current shortcomings

Unfortunately, the current I&M programme for DCVs cannot effectively serve that purpose. The current annual emission test for diesel vehicles does not measure nitrogen oxides (NOX). The programme is also ineffective in identifying advanced vehicles with high PM and NOX emissions. The annual test that most diesel vehicles undergo is open to fraud. These are some of the issues that need to be addressed.

Overseas examples

A number of advanced emission tests have been piloted in the United States (US) and Canada for inspecting and identifying advanced diesel vehicles with excessive emissions. These tests are all conducted under load and performed using advanced emission analysers, and are able to measure NOX, PM, and other air pollutants.

Three advanced emission methods have been discussed in the paper:

  • Remote Sensing Devices;
  • On-road Heavy-duty Measurement System; and
  • Simplified chassis dynamometer test in Hong Kong


  1. To improve emission inspection tests for diesel vehicles: By adopting advanced tests that have been piloted abroad, the Government will significantly improve the effectiveness of the annual emission tests for diesel vehicles and introduce effective roadside screening for diesel vehicles, so that pollution control equipment of diesel vehicles will operate properly year-round.
  2. To enhance mechanics’ training: The complex emission control system that is commonly used in new diesel vehicles demands a sufficient pool of well-trained mechanics to capably diagnose and repair emission-related faults. If a more rigorous I&M programme is put in place in Hong Kong, more properly trained mechanics would be needed for repairing failed vehicles. To ensure all mechanics reach a given level of repair capability, the Government should consider mandating mechanics registration. The Government should also ensure all mechanics have access to reasonably priced training on diagnosing and repairing advanced emission control equipments.
  3. To tighten vehicle emission standards: The Government should tighten the emission standards for heavy-duty diesel vehicles to be on par with Euro VI and the US 2010 standards. These standards require emission control equipment to last longer, and hence may lessen the repair burden on vehicle operators and drivers.
  4. To ensure free access to vehicle service data: Currently, mechanics from small repair shops appear to have less access to repair-related information and tools. The Government should consider following the US and the EU examples and require manufacturers to offer restriction-free access to repair-related information and tools. This will ensure that adequate tools and equipment are available and are used properly by mechanics when repairs are being carried out to advanced vehicles.