---
name: Curb cut effect
slug: curb-cut-effect
category: accessibility
status: published
created: 2026-08-21T00:00:00.000Z
modified: 2026-08-21T00:00:00.000Z
definition: The pattern where something built for a disabled minority turns out
  to serve everyone, the way dropped kerbs serve prams and captions serve noisy
  rooms.
aliases:
  - name: curb cut
    source: community
  - name: solve for one extend to many
    source: microsoft
  - name: electric door effect
    source: community
tags: []
relations:
  contrastWith:
    - situational-disability
  variantOf: []
  partOf: []
  seeAlso:
    - functional-need
implementations: []
sources:
  - title: "Wikipedia: Curb cut effect"
    url: https://en.wikipedia.org/wiki/Curb_cut_effect
  - title: "Microsoft Design: Inclusive 101"
    url: https://inclusive.microsoft.design/articles/inclusive-101-guidebook
demo: inline
exhibit: false
useWhen: justifying accessibility work to a sceptical room
---

The name comes from a piece of civil disobedience. In Berkeley in the early 1970s, disabled
activists, many of them wheelchair users from the campus independent living movement, took
sledgehammers and cement to the kerbs the city would not cut, and the ramps that followed
became the first municipal programme of its kind in the United States. What happened next is
the part the term is actually about: the ramps were used constantly by people who had never
been part of the argument, pushing prams, dragging suitcases, wheeling delivery trolleys,
riding skateboards, walking with a cane. The count was never close. On any given kerb the
intended user is a rounding error against everyone else rolling something.

Digital interfaces repeat the pattern so reliably that it is worth treating as a prediction
rather than a happy accident. [Captions](/captions) were built for deaf and hard of hearing
viewers and are now switched on by people watching in bed, in a gym, in an open-plan office,
or in their second language. Voice control was built for people who cannot use their hands
and became how everyone talks to a phone in a car. Autocomplete reduces the number of
keystrokes a person with limited fine motor control has to make, and it is also why nobody
types a full address any more. High contrast modes were built for low vision and get used
outdoors in the sun. The constraint that forces a clearer design is the same constraint for
everybody; the disabled user just hits it first, and hardest.

This matters most as an argument, because accessibility work is usually killed by the phrase
"edge case". The framing smuggles in a false model of the market: that the population needing
the feature is both tiny and separate from the paying one. Neither half survives contact with
the numbers. Disability is not a fixed minority but a state most people pass through, by age,
injury, illness, or a badly timed hand full of shopping, and the feature almost never stays
in its lane. A team that ships captions to satisfy a regulator ends up shipping a
searchable transcript, better SEO, and a video that works with the sound off in a feed, which
is where most video is watched.

Two cautions keep the term honest. It is an observation, not a justification: the ramp would
be worth building for the people it was built for even if nobody else ever used it, and an
argument that only ever cites the mainstream benefit has quietly conceded that disabled users
alone are not reason enough. And it does not run in reverse. Designing for the majority and
hoping it happens to work for a wheelchair user produces a kerb, not a ramp. The effect only
appears when the constraint drove the design.