Cities are ideal for sharing things like bikes, cars, and office space–just look at the growth of bike-sharing around the world. The advantages are obvious. Sharing makes use of idle resources (like cars sitting in parking lots), and has the potential to cut down on greenhouse gas emissions. Every car shared is another that’s not on the road, which reduces congestion, pollution, and noise.

Shareable, the site for all things sharing, believes the sharing economy could be a big boon for cities, but that they need do more to facilitate it. “City governments can increasingly step into the role of facilitators of the sharing economy by designing infrastructure, services, incentives, and regulations that factor in the social exchanges of this game changing movement,” the site explains in a new report.

Fostering the growth of the sharing economy is the single most important thing that city governments can do to boost prosperity.

It adds: “We believe that fostering the growth of the sharing economy is the single most important thing that city governments can do to boost prosperity and resilience in times of economic crisis and climate change.” The guide, called Policies for Shareable Cities, suggests 32 policy ideas for cities to think about. Here are 10 of the best:

Cities can “increase car-sharing participation by making parking spaces available for shared vehicles both on streets and in off-street public lots and garages,” says the report. Several cities have already done this. San Francisco, for example, offers discount rates at municipal lots.

Allowing people to rent out their driveways would free up space for more car-sharing, and let home-owners supplement their income at the same time. This is something that private companies like Parkatmyhouse are already exploring.

Many people don’t ride-share because they worry about exceptional situations: what if they need to work late, or get home early? Guaranteed ride home programs give “carpoolers peace of mind by covering the cost of a taxi ride or rental car in the event of emergencies or in case of an unexpected departure of the carpool partners.” Minneapolis already has such a scheme.

Cities can give tax credits (or other incentives) to property owners who allow farming on their lots, rather than leaving them empty. “Tax credits create an attractive incentive for property owners to open their land to community gardening or urban farming uses, with desirable public health and safety outcomes for cities,” the guide says. Philadelphia gives a discount on its yearly “vacant lot registry fee” if land is cultivated, for example.