1994/1990 ADAAG — 4.6.2 Location
Accessible parking spaces serving a particular building shall be located on the shortest accessible route of travel from adjacent parking to an accessible entrance. In parking facilities that do not serve a particular building, accessible parking shall be located on the shortest accessible route of travel to an accessible pedestrian entrance of the parking facility. In buildings with multiple accessible entrances with adjacent parking, accessible parking spaces shall be dispersed and located closest to the accessible entrances.
2010 ADA Standards — 502.7 Relationship to Accessible Routes
Parking spaces and access aisles shall be designed so that cars and vans, when parked, cannot obstruct the required clear width of adjacent accessible routes.
2010 ADA Standards — Advisory 502.7 Relationship to Accessible Routes
Wheel stops are an effective way to prevent vehicle overhangs from reducing the clear width of accessible routes.
2010 ADA Standards — 502.3 Access Aisle
Access aisles serving parking spaces shall comply with 502.3. Access aisles shall adjoin an accessible route. Two parking spaces shall be permitted to share a common access aisle.
2010 ADA Standards — 502.3.1 Width
Access aisles serving car and van parking spaces shall be 60 inches (1,525 mm) wide minimum.
2010 ADA Standards — 502.3.2 Length
Access aisles shall extend the full length of the parking spaces they serve.
2010 ADA Standards — 502.3.3 Marking
Access aisles shall be marked so as to discourage parking in them.
2010 ADA Standards — Advisory 502.3 Access Aisle
Accessible routes must connect parking spaces to accessible entrances. In parking facilities where the accessible route must cross vehicular traffic lanes, marked crossings enhance pedestrian safety, particularly for people using wheelchairs and other mobility aids. Where possible, it is preferable that the accessible route not pass behind parked vehicles.