Drivers need access to an official source of emissions standards information, according to the RAC.
The motoring organisation said that millions of drivers have no easy way of knowing how they might be affected by the future roll-out of clean air zones in the UK because there is no comprehensive number plate look-up system for checking a vehicle's Euro emissions category.
A recent survey found that nearly four in 10 drivers haven't heard of the Euro emissions classification system, while nearly two-thirds of those that have either don't know what category their own vehicle falls under or are unsure of it.
The RAC is calling on the government, through the DVLA, to develop a website that lets drivers check a vehicle's Euro emission standard by entering its registration number. And it said that the service should be rolled out well in advance of any clean air zones being established, so that motorists have enough time to check which category their vehicle falls under and if necessary consider changing it.
A similar online look-up service is already available in a number of other European countries.
Transport for London recently launched an online tool that allows motorists to find out if their vehicle is impacted by the new T-Charge by entering their number plate. This shows whether the car meets the minimum Euro 4 standard, but stops short of informing drivers of the vehicle's Euro emissions category, the RAC said.
An emissions checker is also available from HPI, but the RAC said it conducted a range of searches on vehicles of different ages and the tool "did not appear to be comprehensive".
Currently, the only source of detailed vehicle emissions information covering different manufacturers is the Vehicle Certification Agency's 'car fuel data' website. However, drivers cannot simply enter a vehicle registration number -- they must provide several different pieces of information, including the specific model variant of a vehicle.
RAC spokesman Rod Dennis said: "As councils across the UK develop plans to tackle harmful emissions on a local level, we expect millions of drivers will want to find out the Euro emissions category of their vehicle -- and the natural place to look will be on the official GOV.UK website. We've already seen a big increase in traffic to our own website from people trying to find this information and to understand more about what the Euro emissions standard actually means.
"It is simply unacceptable that there is currently no easy-to-use or conclusive online look-up system available -- this will no doubt leave drivers confused about whether or not they are likely to be impacted by the introduction of clean air zones."
Do you know the Euro emissions category of your vehicle?