"Policy goals" won't be enough to protect bicyclists once the cars start driving themselves. Strong standards will be necessary to govern the interactions between cars and bikes in an autonomous future.
The San Francisco Board of Supervisors is considering adopting an "Urban Agriculture Incentive Zone" policy to incentivize the development of urban gardens on empty lots (which actually do exist in San Francisco).
Cleveland, Ohio has pursued an aggressive policy of greening it vacant and underused land. A program called Garden Boyz employs local youth to tend the gardens, keeping the landscape vital and keeping the kids out of gangs.