ADA Parking Requirements: Space Counts, Dimensions, and Van Rules (2024)

9 accessible spaces. That is what a 500-space parking lot requires under ADA §208.2 Table 208.2. Miss that count or skip the van-accessible ratio, and the permit fails. Plan review will not release the certificate of occupancy until every dimension, sign height, and access aisle designation appears on the drawings.

Here is every number from ADA §208 and §502, organized for plan review.

How many accessible parking spaces does a facility require?

Accessible parking scoping is a minimum count of designated spaces within a single parking facility, required by ADA §208.2 wherever parking spaces are provided for public or common use. Each parking facility is calculated separately. Do not aggregate multiple lots on the same site when applying Table 208.2 (Advisory §208.2). The count is based on total spaces in the facility, not on the number of accessible spaces in a specific accessible-only zone.

One important exception: parking used exclusively for buses, trucks, delivery vehicles, law enforcement vehicles, or vehicular impound is exempt from §208, provided lots accessed by the public include a passenger loading zone complying with §503 (§208.1 Exception).

When is a van-accessible space required?

A van-accessible space is a designated parking space that meets wider dimensional standards for vehicles with side-mounted or rear-mounted lifts, required by ADA §208.2.4 at a ratio of 1 van space per 6 accessible spaces (or fraction of 6). If 4 accessible spaces are required, 1 must be van-accessible. If 7 accessible spaces are required, 2 must be van-accessible. The fraction rule applies: any partial group of 6 triggers another van space.

Van spaces must comply with §502’s dimensional requirements for width and vertical clearance. For multi-story parking structures, an exception in §208.3.1 permits all van spaces to be grouped on a single level rather than distributed across floors. Van spaces serving angled parking bays must have the access aisle on the passenger side of the space, per §502.3.4.

What are the minimum dimensions for accessible parking spaces?

Car parking space dimensions are defined as a minimum clear width of 96 inches (2440 mm), measured and marked to define the width, per ADA §502.2. Van parking space dimensions are 132 inches (3350 mm) wide minimum under the same section. An exception permits van spaces at 96 inches (2440 mm) wide minimum when the adjacent access aisle is 96 inches (2440 mm) wide minimum, creating a wider-aisle van configuration.

Both car and van spaces must meet the surface requirements of §302: stable, firm, and slip-resistant. Two accessible spaces may share one common access aisle (§502.3). Space width is measured from the edge marking to edge marking, not from the center of stripes.

What does an access aisle require?

An access aisle is the marked zone adjacent to an accessible parking space that provides vehicle door clearance and a connection to the accessible route, governed by ADA §502.3. The minimum width is 60 inches (1525 mm) for aisles serving car spaces and standard van spaces (§502.3.1). An access aisle must extend the full length of the parking spaces the aisle serves (§502.3.2). The aisle must be marked to discourage parking in the aisle; ADA does not prescribe color or specific marking method, though state or local law may (§502.3.3).

Access aisles must not overlap the vehicular drive lane (§502.3.4). Aisles may be placed on either side of a car space. For angled van spaces, the access aisle must be on the passenger side of the van, per §502.3.4. The aisle surface must be at the same level as the parking space. Changes in level are not permitted. A slope not steeper than 1:48 is permitted for drainage (§502.4).

What vertical clearance do van parking routes require?

Vertical clearance is the minimum unobstructed overhead height measured from finished grade or floor to the lowest overhead obstruction, required by ADA §502.5 at every point on the van parking route. The minimum is 98 inches (2490 mm). The 98-inch requirement applies to three separate zones: the van parking space itself, the access aisle serving the van space, and the entire vehicular route from the parking facility entrance to and from the van space.

The three-part scope matters on structured parking levels with low-clearance ramps and mechanical systems. A van space with compliant dimensions served by a lower-clearance entry ramp fails §502.5. The vehicular route includes entry drives, ramp headroom, and any overhead obstructions along the path. In multi-story structures, one compliant level with a compliant vehicular route fully satisfies the 98-inch requirement when all van spaces are grouped on that level per the §208.3.1 exception.

What signage does each accessible parking space require?

Accessible parking signage is a post-mounted or wall-mounted sign displaying the International Symbol of Accessibility (ISA), required by ADA §502.6 at each accessible parking space. The sign must comply with §703.7.2.1 for the ISA symbol. The bottom of the sign must be mounted at least 60 inches (1525 mm) above the finish floor or ground surface.

Van-accessible spaces require an additional “van accessible” designation on the sign, per §502.6. The van designation may appear on the same sign as the ISA or on a separate supplemental sign. A sign that displays only the ISA without the van designation on a van space does not comply with §502.6. Signs placed inside accessible spaces at ground level, where a parked vehicle would obscure them, are a common installation error. The 60-inch mounting height measured to the bottom of the sign keeps the sign visible above vehicle bumpers and hoods.

Why do these numbers exist? — DataDrivenAEC

ADA parking scoping and dimensions are derived from the physical requirements of wheelchair users, ambulatory individuals with mobility impairments, and users of vehicles equipped with lift devices, as required by ADA §208 and §502 for all covered parking facilities. The 96-inch car space width allows a car door to open fully and a wheelchair user to transfer laterally to the vehicle seat. The 60-inch access aisle provides clearance for the open door and the wheelchair approach path. The 132-inch van space provides space for a side-mounted lift to deploy fully. The 98-inch vertical clearance allows a lift-equipped van to pass through without obstruction.

DataDrivenAEC’s comparison of the 4 facility-type minimums in §208.2 found that healthcare parking requirements can reach 10 times the commercial scoping rate. A rehabilitation or outpatient physical therapy facility requires 20 percent of patient and visitor spaces to comply with §502 (§208.2.2), while a standard commercial lot at 501 to 1000 spaces requires only 2 percent. The 10x gap reflects the higher proportion of mobility-impaired users at specialized healthcare facilities.

The part everyone gets almost right — DataDrivenAEC

1. Applying the scoping table to accessible-zone spaces, not total spaces. The scoping table counts total spaces in the facility. A 500-space lot with 10 accessible-zone spaces still requires 9 per §208.2 Table 208.2. The count does not reset within a zone.

2. Missing the van fraction rule. Section 208.2.4 requires 1 van space per 6 accessible spaces, or fraction of 6. A facility requiring 7 accessible spaces needs 2 van spaces, not 1. Rounding down to the nearest whole group fails the fraction rule.

3. Aggregating multiple lots on one site. Advisory §208.2 is explicit: each parking facility is calculated separately. Two 200-space lots on a campus are two separate calculations, not one 400-space calculation. Aggregating them understates the required count.

4. Placing the access aisle on the driver side of an angled van space. Section 502.3.4 requires the access aisle for angled van spaces to be on the passenger side. A driver-side aisle on an angled van space does not comply, even if the aisle width is correct.

5. Omitting the van designation on the sign. Section 502.6 requires a “van accessible” label on every van-accessible space sign. A sign showing only the ISA symbol on a van space is a non-compliance. Plan review and inspection both catch this.

How DataDrivenAEC automates accessibility compliance checking

This compliance check takes 2–4 hours manually. DataDrivenAEC builds custom agents that run this check on your drawing set and deliver the findings as a structured report. See all agents →