Page 78 - The Engineering Guide to LEED-New Construction Sustainable Construction for Engineers

LEED Sustainable Sites 59

SS Credit 4.4: Alternative Transportation—Parking Capacity

USGBC Rating System
This credit is worth two points in LEED 2009 and was worth one point in LEED 2.2. The
intention of this credit is to limit the sizes of parking facilities and the number of vehicle
trip generations to the site. Trip generation is a term used in transportation engineering
to represent the amount of vehicular traffic generated in a network by an activity at a
location. The Institute of Transportation Engineers (ITE) publishes a manual that gives
representative values for different site uses and street volumes. This reduction from the
estimated trip generation for typical, usually single-occupancy, vehicles is accomplished
by encouraging the use of carpooling or other shared-ride methods. LEED-NC 2.2 lists
the Intent, Requirements, and Potential Technologies and Strategies for this credit as
follows, with modifications for LEED 2009 as noted, including the renumbering of
options and segregation by cases:

Intent
Reduce pollution and land development impacts from single occupancy vehicle use.
Requirements
LEED 2009 CASE 1. NON-RESIDENTIAL PROJECTS
OPTION 1—NON-RESIDENTIAL
Size parking capacity to not exceed minimum local zoning requirements AND provide
preferred parking for carpools or vanpools for 5% of the total provided parking spaces.
OR
OPTION 2—NON-RESIDENTIAL
For projects that provide parking for less than 5% of FTE building occupants:
Provide preferred parking for carpools or vanpools for 5% of the total provided parking
spaces. In both Option 1 and Option 2 of LEED 2009 Case 1, an alternative is to provide a
discounted parking rate for vanpools or carpools. This must be at least a 20% discount and
be available for all carpool or vanpool vehicles for a minimum of two years and publicly
posted at the entrance of the parking area.
OR
OPTION 3—NON-RESIDENTIAL
Provide no new parking.
OR
LEED 2009 CASE 2. RESIDENTIAL PROJECTS
OPTION 1—RESIDENTIAL
Size parking capacity to not exceed minimum local zoning requirements, AND, provide
infrastructure and support programs to facilitate shared vehicle usage such as carpool
drop-off areas, designated parking for vanpools, or car-share services, ride boards, and
shuttle services to mass transit.
OR
OPTION 2—RESIDENTIAL
Provide no new parking.
LEED 2009 CASE 3. MIXED USE (Residential with Commercial/Retail) PROJECTS