ADA Parking & Aisle Striping: Widths and Spec

The Aisle Is Not Optional Space

The striped, diagonally hatched area next to an accessible parking space is the access aisle, and it is the single most misunderstood part of an accessible stall. People treat it as wasted pavement or, worse, as an extra place to squeeze a car. It is neither. The aisle is the room a person needs to deploy a ramp or lift, transfer to a wheelchair, and move clear of the vehicle. Stripe it wrong and the space fails, no matter how perfect the stall beside it looks.

Our ADA parking compliance guide for Oregon covers the whole accessible-parking picture. This page drills into the aisle itself: how wide, how marked, and how to paint it so it actually works.

Required Aisle Widths

There are two widths, and which one you use depends on whether the adjacent space is a standard accessible space or a van-accessible space.

Adjacent Space Type	Minimum Access Aisle Width
Standard accessible	5 feet
Van-accessible (8-ft space option)	8 feet

The aisle must run the full length of the parking space it serves. A 5-foot aisle that only spans part of the stall does not meet the standard. The width is measured between the stripe lines, edge to edge of the usable clear space, not center to center.

Van-accessible layouts have a second option: an 11-foot-wide space paired with a 5-foot aisle instead of an 8-foot space with an 8-foot aisle. Either combination totals 16 feet. The wider aisle is generally the more flexible choice in tight lots, and our page on van-accessible spaces in Oregon compares the two options in detail.

Marking the Aisle: Hatching and Text

A blank aisle reads to drivers as open pavement. The markings are what tell people to keep it clear.

• Diagonal hatching. The aisle interior is striped with diagonal lines, typically at a 45-degree angle, to visually flag it as a no-parking zone. Spacing of roughly 24 to 36 inches between hatch lines is common practice.
• Border lines. The aisle is bounded by solid stripe lines on each side, defining its edges against the parking space and the drive aisle.
• NO PARKING text. While federal ADA does not mandate the words, Oregon and most jurisdictions expect "NO PARKING" stenciled within the aisle. It is cheap insurance against people treating the aisle as a space and it strengthens enforcement.
• Paint color. Blue is the conventional color for accessible markings, though white hatching with blue borders is also widely used. Consistency across the lot matters more than the specific palette.

The standard line width for the hatching and borders follows the same 4-inch convention used for the rest of the lot's striping. Our Oregon ADA striping requirements for 2026 page covers the paint and layout specs in full.

Shared Aisles: One Aisle, Two Spaces

You do not need a separate aisle for every accessible space. Two accessible spaces can share a single access aisle placed between them, with one space on each side. This is the most space-efficient layout and it is fully compliant as long as the aisle meets the width required by the wider of the two adjacent spaces.

If one of the two shared spaces is van-accessible, the shared aisle must be 8 feet wide to satisfy the van requirement. You cannot give a van space a 5-foot aisle just because it is sharing with a standard space. The aisle always defaults to the most demanding space it touches.

Level, Connected, and Clear

Width and markings are the visible part. Three requirements are easy to miss because they involve how the aisle sits in the lot, not how it is painted:

• Level with the space. The aisle must be at the same level as the parking space it serves, with a slope no greater than 2 percent in any direction. A curb, a lip, or a sloped gutter pan breaking the plane between space and aisle defeats it.
• Connected to a route. The aisle has to connect to an accessible route leading to the building entrance. An aisle that dead-ends at a curb with no ramp is a barrier, not an access point.
• Genuinely clear. Cart corrals, snow piles, landscape islands, and delivery staging do not belong in or overlapping an aisle. The markings only work if the space behind them stays open.

Common Aisle Striping Mistakes

These are the aisle errors that show up most often during a compliance review:

• Aisle too narrow. A 5-foot aisle striped next to a van space, or an aisle that measures 4 feet 6 inches because the layout got compressed.
• Aisle shorter than the space. Hatching that stops short, leaving part of the stall without adjacent clear space.
• No hatching or faded hatching. An aisle marked only with border lines reads as a parking space to drivers. Faded hatching has the same effect.
• Missing NO PARKING text. Without it, enforcement is harder and drivers park in the aisle, blocking the very access the aisle exists to provide.
• Aisle on the wrong side or sloped. An aisle that is not level with its space, or that sits where the accessible route cannot reach it.

Every one of these is correctable during a restripe, and most are layout decisions rather than construction. The dimensions of the spaces those aisles serve are covered in our ADA parking stall dimensions guide.

Why the Stripe Spec Matters for Durability

Oregon's rainy season and UV exposure fade traffic paint faster than many owners expect. A perfectly striped aisle that has faded to 40 percent visibility is functionally the same as an unmarked aisle in the eyes of an auditor. That is why aisle hatching should be inspected at least annually and repainted before it disappears. Pairing aisle restriping with a sealcoat gives the paint a clean, dark surface to bond to and improves contrast for the blue and white markings.

This is general guidance, and every lot is different. Aisle width, placement, and slope all depend on your specific layout, which is why a site survey beats any spec sheet. A contractor who measures the lot before painting catches the narrow aisle or the wrong-side placement before it becomes a violation.