Editor's Note: ADA standards and accessibility guidelines clearly
state that no greater than a 2% cross slope for parking spaces should be applied
in all directions:
1990/1994 ADAAG Section 4.6.3* Parking Spaces. “... Parking
spaces and access aisles shall be level with surface slopes not exceeding 1:50
(2%) in all directions.”
2010 ADA Section 502.4 Floor or Ground Surfaces. “Parking
spaces and access aisles serving them shall comply with 302. Access aisles shall
be at the same level as the parking spaces they serve. Changes in level are not
permitted. EXCEPTION: Slopes not steeper than 1:48 shall be
permitted.” (The exception allows sufficient slope for drainage. Built-up
curb ramps are not permitted to project into access aisles and parking spaces
because they would create slopes greater than 1:48.)
Advisory for 502.4 Floor or Ground Surfaces. “Access aisles
are required to be nearly level in all directions to provide a surface for
wheelchair transfer to and from vehicles.”
A: Steep slopes in any direction threaten the safety and
ability of the user who’s trying to control a wheelchair while exiting a car and
then closing the door.
Alex, I am so glad that your question includes the fact that the
professionals you trust are giving you different opinions. I can’t tell you how
often engineers or construction/parking lot layout plans place the designated
ADA parking space too close to a building that has a steep slope approach.
The problem is, they haven’t considered that for a wheelchair user trying to
exit or enter a vehicle, extreme slopes are dangerous. I understand that your
professionals might feel torn between two different requirements (i.e.,
convenient parking vs. maintaining a level surface). But the level surface must
be the priority.
Please do everything possible to plan accessible parking spaces carefully and
with landscaping that will fulfill ADA requirements for both close and level
I have an exercise for anybody who feels up to the challenge:
1. Place a folding chair equipped with wheels in the back
seat of your car.
2. Next, park in a sloped location and remove the chair
while you remain sitting in your driver’s seat.
3. Place the chair on the ground next to your car door (the
chair may start rolling away due to the unlevel surface).
4. Meanwhile, try to transfer from the vehicle to the chair
without using your legs. Imagine they have no strength.
How are you doing? By now, this activity should drive home why a level
parking space and adjacent access aisle is imperative in parking lot designs.
If you didn’t try my exercise above, examine the graphic below that depicts a
driver using a manual chair. This illustration should help you understand the
difficulty in trying to control the wheelchair on a severe slope.
As a wheelchair user, I have fallen off my ramp on a sloped parking space too
many times, especially in inclement weather. I have ruined clothes and injured
my knees — but I’m lucky. At least I can crawl, unlike paraplegics or
Take a look at the parking lot pictures to the left, taken by yours
truly. The slope in the top picture is severe and there are not enough access
aisles in the left picture. I run across these situations often. Improperly
designed parking spaces are among my biggest pet peeves, so I will address the
different issues related to accessible parking over the coming months.
This Illustration can be found in the Uniform Federal
Accessibility Standards (UFAS) retrofit manual.