ADA Accessible Route: Connecting Parking to the Door

The Space Is Only Half the Job

A perfectly striped accessible parking space connected to nothing is not accessible. The space exists so a person can park, but the point of parking is to reach the building. The continuous path from the accessible space to the entrance is the accessible route, and it is just as much a compliance requirement as the space itself. A lot can have flawless accessible spaces and still fail because the route from them is broken.

This page covers what makes an accessible route compliant: width, slope, surface, curb ramps, and the detectable warnings where pedestrian paths meet vehicle traffic. Our ADA parking compliance guide for Oregon covers the full standard; this page focuses on the path of travel.

What the Accessible Route Connects

The accessible route is the continuous, unobstructed path that links the elements of a site a person needs to use. From the parking lot's perspective, it connects:

• The access aisle beside each accessible space
• The route across the lot, including crossing drive aisles
• Any curb ramps where the route transitions between levels
• The path to the accessible building entrance

"Continuous" is the operative word. The route cannot have gaps, dead-ends, or segments that force a person off the accessible path. If any single link breaks, the whole route fails, even if the rest is perfect.

Width and Slope

The accessible route has dimensional requirements that govern whether a wheelchair or mobility device can actually use it.

• Width. The route must be at least 36 inches wide for its clear width, with allowances for short pinch points. This is enough for a wheelchair to pass.
• Running slope. The route's running slope (the direction of travel) generally must not exceed 5 percent. Steeper than that and the segment becomes a ramp, which carries its own handrail and landing requirements.
• Cross slope. The cross slope (side to side) must not exceed 2 percent, the same limit that applies to accessible spaces and aisles, which we cover in our ADA parking slope requirements page.

A route that meets width but exceeds slope, or vice versa, is non-compliant. Both have to be right along the entire length.

Surface Requirements

The route surface must be firm, stable, and slip-resistant. That rules out loose gravel, deteriorated asphalt with crumbling aggregate, and surfaces that become slick. It also sets limits on the imperfections that create trip and roll hazards:

• Level changes greater than a quarter inch must be beveled; changes over a half inch require a ramp.
• Gaps and cracks wider than a half inch along the route are hazards.
• Potholes and ponding anywhere on the route are barriers requiring repair.

In Oregon, freeze-thaw and the long rainy season degrade route surfaces, so a route that was compliant when built can develop trip hazards and ponding over the years. The route deserves the same monitoring as the accessible spaces themselves.

Curb Ramps: Where the Route Changes Level

When the accessible route has to move between a parking surface and a sidewalk, the transition is made with a curb ramp, not a curb. Curb ramps have their own requirements: a running slope generally capped at a defined maximum, flared sides where pedestrians cross them, a level landing at the top, and a width adequate for the route.

A curb that interrupts the route without a ramp is a hard barrier. So is a curb ramp that is too steep, too narrow, or lacks a landing. Many older lots have accessible spaces that connect to a sidewalk only over a full-height curb, which silently breaks the route. Correcting that means installing a proper curb ramp.

Detectable Warnings

Where the accessible route crosses into a zone of vehicular traffic, or transitions at certain curb ramps, the standard calls for detectable warnings: the truncated-dome surface that a person using a cane or with low vision can feel and see. These warn that the pedestrian path is about to meet vehicle traffic.

Detectable warnings have specific requirements for dome size, spacing, contrast, and placement, and getting the placement right is its own topic, which we cover in our detectable warning and curb cut placement page. Missing or incorrectly placed detectable warnings are a common gap on routes that otherwise look fine.

How Routes Get Broken

Accessible routes fail in predictable ways:

• A curb with no ramp between the accessible space and the sidewalk
• A route that forces crossing a busy drive aisle with no marked crossing
• Excessive slope on a segment that should be a route but functions as an unmarked ramp
• Surface deterioration creating trip hazards or ponding
• Obstructions like bollards, planters, or parked cars narrowing the route below 36 inches
• A missing detectable warning where the route meets traffic

Each of these is correctable, but the fix depends on the cause. A surface issue is repair; a missing ramp is construction; a slope issue may be regrading. An ADA compliance audit process identifies which links in the route are broken and what each needs.

Designing the Route With the Lot

The accessible route is easiest to get right when it is planned together with the parking layout, not bolted on afterward. Accessible spaces should be placed where the shortest, flattest route to the entrance is achievable, so the route does not have to fight the lot's grade or cross unnecessary traffic. When a lot is being striped, paved, or reconfigured, that is the moment to verify the route end to end.

This is general guidance, and the specifics, route length, slope, curb ramp placement, depend on your site. A survey that walks the full path from accessible space to door is the way to confirm the route works.