Park-and-ride (or incentive parking) facilities are car parks with public transport connections that allow commuters and other people headed to city centres to leave their vehicles and transfer to a bus, rail system (rapid transit, light rail, or commuter rail), or carpool for the remainder of the journey. The vehicle is left in the car park during the day and retrieved when the owner returns. Park-and-rides are generally located in the suburbs of metropolitan areas or on the outer edges of large cities. Park-and-ride is abbreviated as "P+R" on road signs in the UK, and is also mentioned as P&R in colloquial speech and writing.