No vehicles were summoned by the Malta Transport Authority (ADT) for emission testing since last year, a report has found.
Through text messages, the public reported 30 per cent of the public transport vehicles as opposed to 10 and four per cent of commercial and private vehicles respectively.
However, the potential of the Emissions Alert Campaign (EAC) was not fully realised, mainly because a large number of reported vehicles were not summoned for testing.
Although the ADT applied a higher filtering threshold than that prescribed, its testing capacity was still unable to cope, according to the Auditor General's report tabled in Parliament.
The vehicle emissions' control schemes have brought about "some improvement" in compliance but, despite this, the framework had to be strengthened further.
The fine-tuning of these schemes, through enhanced planning, implementation and enforcement, should contribute towards a more robust and sustainable vehicle emissions' control framework, the report noted.
It proposes that the framework be reviewed to ascertain that the relative schemes are not piecemeal or incremental but designed as part of a holistic and comprehensive strategy, aimed at tackling excessive vehicle emissions.
The report also recommends that, in conjunction with the recently-introduced fiscal measures related to vehicle licensing, annual Vehicle Roadworthiness Tests for older cars would also be considered and penalties introduced in cases where fuel pump seals are found to be broken.
Vehicle emissions are a major source of air pollution, which impacts negatively on public health and the environment. Their effects are further aggravated by Malta's high vehicle density and the fact that the average age of cars is much higher than the EU average.
The audit focused on the four schemes of the vehicle emissions' control framework, namely the VRT, the emissions' campaign, the Roadside Technical Inspection and the Roadside Emissions Test of the Local Enforcement Scheme.
For the VRT, only 1.2 per cent of the tested vehicles were found to have excessive emissions, with the highest risks emanating from diesel engines, commercial and vehicles aged eight years and over.
The audit revealed the VRT compliance effect diminished substantially soon after passing this test.
Inspections to ascertain that VRT stations conducted tests in accordance with the regulations were not fully adequate or risk-based, it found. The alert campaign had been successful in raising public awareness, bringing about enforcement and reducing vehicle emissions, according to the report.
The roadside emissions' test and the technical inspections, intended to ensure owners maintain their vehicles in a roadworthy condition at all times, were able to identify a significant number of vehicles with excessive emissions.
Non-compliant vehicles were detected throughout all vehicle age groups and engine capacities. However, the roadside testing regime did not adequately target petrol engine vehicles because the latter's emissions tend to be invisible, albeit very harmful. Moreover, roadside emissions' tests were suspended last year as the ADT sought to limit the conduct of emission testing to certified testers.