UPDATE: We've summarized much of the series this article is part of in a new report, Policies for Shareable Cities: A Sharing Economy Policy Primer for Urban Leaders. Get your free copy here today.

What can a city do to bring car sharing to every city block? What would make car sharing a viable option for everyone and greatly reduce the number of cars clogging our streets? Car-sharing programs like City Car Share and Zipar have begun to place cars around our cities, and now companies like RelayRides and Getaround are helping people share their own cars with others.

Cars parallel parked on a street in Winchester. Photo credit: Cyren. Used under Creative Commons license.

Here are a few ways a city might foster widespread car sharing:

1. Designate on-street parking spaces for cars that are part of a car-sharing program: Innovative Mobility has done some great research on parking policies and car sharing. Given the findings that every shared car results in a handful of cars being taken off the road, designating street parking for shared cars will actually result in more on-street parking. San Francisco has caught on to this and recently started renting street parking spaces to City Car Share. In particular, cities should increase parking for shared cars near public transportation hubs.

2. Allow people to lease their residential parking spots: Parking sharing is a smart use of resources, and someone with an empty driveway could offer a valuable parking spot to a car-sharing program – or anyone’s car, for that matter. But earning money by leasing a parking spot could run a property owner up against laws that prohibit people from using their properties for certain business uses. Cities should clarify that leasing a parking space like this is an acceptable home business use of a property.

3. Legalize off-street parking spots for cars that are part of a car-sharing program: It turns out that just because a space is paved doesn’t mean it’s legal to park a car there. Currently, many of the car share-designated spaces in gas stations and private driveways are technically illegal parking spots. Cities also tend not to allow tandem parking in driveways. A city should legalize additional off-street parking spaces to allow those spots to be used by shared vehicles. Furthermore, by the same reasoning that it is legal to block your own driveway by parallel parking, it should be legal to designate tandem parking spots in driveways. In both cases, one car will have to be moved for the other to leave, and residents should be allowed to set up their parking this way if they wish.

4. Make it expensive for other cars to park on the street: A city could incentivize car sharing by disincentivizing individual car ownership. Many cities make car owners pay an annual fee of between $30 and $200 in order to park a car on the street. Raising that fee is justifiable, given the high cost to a city of maintaining street parking and the social/environmental cost of every car in existence.

5. Subsidize or require car-sharing programs in new multi-unit developments: Car sharing could easily be administered by a condo-owners' association or apartment manager in a multi-unit development. To offset the traffic and parking impact of new developments, cities could subsidize or require that the new development include a plan or program for car sharing.

How else might a city foster car sharing and parking sharing? Please post your thoughts below and help us build this collection of policy proposals. Thank you!

This post is one of 15 parts of our Policies for a Shareable City series with the Sustainable Economies Law Center:

1. Car Sharing and Parking Sharing
2. Ride Sharing
3. Bike Sharing
4. Shareable Commercial Spaces
5. Shareable Housing
6. Homes as Sharing Hubs
7. Shareable Neighborhoods
8. Shareable Workspaces
9. Recreational and Green Spaces
10. Shareable Rooftops
11. Urban Agriculture
12. Food Sharing
13. Public Libraries
14. The Shareable City Employee
15. How to Rebuild the City as a Platform