http://en.wikipedia.org/wiki/Pay_and_displayPay and display machines are a subset of ticket machines used for regulating parking in urban areas or in carparks. It relies on a customer purchasing a ticket from a machine and displaying the ticket on the dashboard, or windscreen or passenger window of the vehicle.
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http://www.roadtraffic-technology.com/contrac...Metric Group - Pay and Display Machines
Metric are widely recognised as one of the world’s leading manufacturers of pay and display machines, with a reputation for quality and reliability that is second to none.
Encarta:
http://encarta.msn.com/encnet/features/dictio...pay and dis·play
U.K. parking system: a parking system in which motorists buy tickets from a machine in a parking lot and leave them on display in the windshields or windows of their vehicles. Motorists pay for the amount of time they intend to stay, which is printed on the ticket.
And if a Pay and Display machine isn’t working customers can go to another ... For more information on the on-street Pay and Display machine test program, ...
http://www.calgaryparking.com/PDM.php3Visitor parking is available at all times by purchasing a ticket from the pay and display machine. A valid permit must be displayed at all times. ...
http://www.adm.uwaterloo.
ca/infopark/lots/descriptions.html
Use of pay and display machines | Parking when pay and display machine is broken | Requesting a refund | Hours of operation ...
http://www.aucklandcity.govt.
nz/auckland/transport/parking/restrictions.asp
Thieves steal a pay and display machine from a car park before breaking it into pieces and taking £1000 in coins.
http://news.bbc.co.
uk/.../news+sport/callow+hill+worcestershire/-/2/hi/uk_news/england/hereford/worcs/4141062.stm