This is where "contingency-based planning" can help. Here is Todd Litman's Online TDM Encyclopedia to explain:
Contingency-Based Planning is a Planning strategy that deals with uncertainty by identifying specific responses to possible future conditions. ...
A contingency-based plan typically consists of various if-then statements that define the solutions to be deployed if certain problems occur: if parking supply proves to be inadequate then we will implement certain strategies, and if those prove to be insufficient then we will implement an additional set of strategies.
For example, a Contingency-Based parking plan might initially allow developers to build fewer parking spaces than required by conventional minimum parking standards, with a list of solutions that will be applied if that proves inadequate and motorists experience significant problems finding parking or neighbors experience parking spillover problems.
These solutions might include a combination of additional capacity (some land might be reserved for future parking lots, or a potential budget identified to build a parking structure, if needed), various Parking Management strategies (such as programs to encourage employees to use alternative modes, arrangements to share parking facilities with nearby buildings, and increased regulation and pricing of onsite parking), and improved enforcement if needed to address any spillover problems.
Contingency planning allows extra supply to become a last resort not the default choice.
So requiring 'potential parking' rather than parking itself (as I mentioned in a recent post) is one example of contingency-based planning applied to parking.
In response to that same post, Donald Shoup emailed to point to an example from the Silicon Valley which is mentioned in his 2005 book:
To deal with the uncertainty in predicting the demand for parking, some cities allow developers to provide fewer parking spaces if they set aside land that can later be converted to parking if demand is higher than expected. Palo Alto, California, allows reductions of up to 50 percent in parking requirements if the difference is made up through a landscaped reserve, and none of these landscaped reserves have subsequently been required for parking. One apartment development was granted a request to defer 22 of the 95 parking spaces required by city code, using the land instead for a family play lot, a barbeque area, and picnic benches, Nearly 15 years after construction, the landscape reserve has not been needed for parking, and the open space constitutes an important environmental and social benefit for the community.
[See page 43 (and a chapter endnote from there) in the High Cost of Free Parking.]
Litman's Online TDM Encyclopedia page provides an example of a contingency-based parking management plan for a development that has been permitted to provide fewer parking spaces than traditionally required. It lists 20 interventions that could be tried (in phases) if any parking problems emerge. These would be tried BEFORE considering resorting to increasing supply. They include:
- Improve parking information with signs and a parking facility map.
- Shift from dedicated parking spaces to “open” (shared) parking spaces in each lot.
- Impose 2-hour limitations on the most convenient parking spaces.
- Encourage employees to use less convenient parking spaces.
- Improve enforcement of parking regulations and fees.
- Establish an evaluation program, to identify impacts and possible problems.
- Price the most convenient parking spaces.
- Arrange shared parking agreements with neighbors that have excess parking supply.Install bicycle storage and changing facilities.
- Establish a commute trip reduction program.
- Gradually and predictably increase parking fees (e.g., 10% annual price increases).
- Improve area walkability and address security concerns.
- Provide real-time information on parking availability using changeable signs
- Develop overflow parking plans for special events and peak periods.