Google has launched Google Transit, an add-on service to Google Maps that incorporates public transport routes and schedules to allow users to plan journeys across town.

The new service is being launched in Brussels together with the city's public transport operator MIVB/STIB and will be rolled out in other cities in Europe at a later date, Google said. The service is already available in several US cities including New York, Boston and Chicago.

It is accessible via smart phones equipped with satnav software.

"The launch of Google Transit in Europe's capital will make it easy for residents and visitors alike to use the Brussels public transport system more often, and more efficiently," said Ed Parsons, geospatial technologist at Google.