B49P96 Park sign showing arrow with building in background. Image shot 09/2008. Park; Sign; Arrow; City; Downtown; Parking; Chic

​Parking spaces are so valuable in American cities that mobile phone auctioning apps have been popping up allowing motorists to sell their parking space to the highest bidder.

Apps like MonkeyParking mean a driver about to leave a space can sell the spot to another app-user looking for parking for as much as $20 (£11.83).

However not everyone thinks this is a great idea. Dennis Herrera San Francisco's city attorney has sent a cease and desist letter to MonkeyParking. He stated that the app created "a predatory private market for public parking spaces," reports the Telegraph.

As of yet this hasn't stopped other apps such as Haystack emerging in Baltimore and Boston. Boston councilor Frank Baker has other ideas though and has proposed an order that states no one other than the city "shall have the authority to sell, lease, reserve or facilitate the reserving of any street, way, highway, road or parkway, or portion thereof, under the City of Boston's control."

The councilor said: "People shouldn't be coming in to profit off our assets. What is next, reserving park benches? Swings? Tables on the Greenway?"

Haystack CEO Eric Meyer doesn't see the problem and issued this statement in response to Baker.
He said: "Haystack does not sell, lease or reserve parking spots, but rather allows neighbours to exchange information about parking. And neighbours have every right to share information with one another.

"While we are unaware of this ordinance and will need to study it further, any attempt to deny Boston residents access to such information is a step backwards in reaching our common goal of simpler streets and parking innovation for city residents."