Google Maps will now alert drivers in major cities if they are entering a low-emission zone.
Several cities around the world have introduced schemes to limit polluting traffic out of busier areas, although this can prove confusing for some tourists or occasional drivers.
To help, Google Maps will now warn drivers entering such zones in London, Paris, Barcelona, Amsterdam and Berlin.
Google said: "The alerts will appear when planning a trip that goes through a low-emission zone and when nearing a zone while already en route to the destination."
There will also be links to official local information to help drivers adapt their journey.
They added: "Based on this info, impacted users can choose an alternative mode of transportation or take another route."
In London, the Ultra Low Emission Zone (Ulez) covers an area including many major historical landmarks and tourist hotspots with the boundaries running from Mayfair (west) to Whitechapel (east), and from Clerkenwell (north) to Lambeth (south).
Anyone driving an older car below modern emission standards needs to pay £12.50 in that zone.
