LEED defines residential neighborhood or area as a minimum of 10 living units (i.e. an apartment unit or house) per acre. Apartment buildings, neighborhoods, or dormitories can all contribute to this.
If a proper contract agreement of two years and designated space are provided through an alternative compliance method, then a shared car service may be accepted as a “carpool or vanpool” substitute. See LEED Interpretation ID#3138, 1/26/2005, in which Reviewers define car share services, and LEED Interpretation ID#3137, 5/24/2004, in which Zipcar is discussed as a carpool substitute for residential projects.
There aren't specific standards, but projects are expected to adequately communicate to occupants about the location and purpose of preferred parking spaces, typically by use of pole, wall-mounted, and/or pavement markings.
The LEED MPRs require you to allocate parking between multiple buildings. Allocation may be determined by an "appropriate percentage" of use.
You would need to work with the parking authority or management to designate the preferred parking.
Since the LEED Online form doesn't have an Option 4 choice, you'll need to indicate with the checkbox under "Additional Details" that you're using an alternative compliance path. For more information, see LEEDuser's analysis of the ITE study.
Yes. Rebuilding a current parking lot with fewer spaces will meet the credit intent.
The Minimum Program Requirements supplemental guidance document covers these situations in some detail. The boundary needs to include "contiguous land that is associated with and supports normal building operations."
The Reference Guide gives little guidance for this and states projects will be evaluated on a case-by-case basis. LEED 2009 requirements are more specific, and while not officially applicable, provide some direction.