Curb Cut Effect

Design for disability, and everyone benefits.

Features built for disabled people end up used by far more people than they were designed for. Curb cuts, captions, and text-to-speech began as accommodations and became things everyone relies on.

Origin

Curb cuts appeared in Kalamazoo, Michigan, as early as 1945, but the ones that changed the country came from Berkeley, California. In the early 1970s, disability activist Michael Pachovas and friends poured cement into a crude ramp at a curb, and in 1972, pressed by activists, the city installed its first official curb cut on Telegraph Avenue. The Americans with Disabilities Act of 1990 made them standard.

Then everyone started using them: parents with strollers, workers with carts, travelers with luggage. A study at a Sarasota, Florida, shopping mall found that nine out of ten unencumbered pedestrians went out of their way to use a curb cut. Angela Glover Blackwell named the curb-cut effect in a 2017 essay: changes designed for one excluded group end up benefiting everyone.

The Effect

Features designed for disabled people end up used and valued by a far larger group than they were made for. The effect is a cousin of universal design, but it is often unplanned: the wider benefit shows up only after the accommodation exists.

Origin
Berkeley curb cuts (1972) · named by Angela Glover Blackwell (2017)
Also called
Curb-cut principle
In practice
Design for disability, benefit everyone
When to Use
How to Use
The classic 01 / 10

Ramps for Everyone

Curb cuts were made for wheelchairs, and then strollers, carts, luggage, bikes, and runners took them over. Today few people notice them as an accessibility feature at all, which is the mark of the effect working.

Best for
Explaining the effect
Use when
Arguing for an accessibility feature
Avoid when
The feature is an individual accommodation
Media 02 / 10

Captions for Everyone

Captions written for deaf and hard-of-hearing viewers are used in loud places, in quiet offices, by language learners, and on videos that autoplay muted. Caption every video with speech.

Best for
Video and audio content
Use when
Media plays on the page
Avoid when
The video has no speech or meaningful sound
Spectrum 03 / 10

Permanent, Temporary, Situational

Microsoft’s inclusive design toolkit pairs a permanent disability with temporary and situational versions: one arm, an arm in a cast, a parent holding a baby. Design for the permanent case and the others come along.

Best for
Framing accessibility work
Use when
Deciding whom to design for
Avoid when
Treating situational users as the main audience
Input 04 / 10

Keyboard Access Speeds Everyone Up

Keyboard navigation built for people who can’t use a mouse is also how power users fly through a product. A logical focus order and visible focus help everyone who prefers the keys.

Best for
Forms, tools, and productivity apps
Use when
People repeat tasks often
Avoid when
The device has no keyboard at all
Listening 05 / 10

Text-to-Speech on the Commute

Text-to-speech was built for blind people, and now people listen to articles, papers, and books while commuting or multitasking. Semantic markup and real text make it work for both.

Best for
Long articles and documents
Use when
Content is read at length
Avoid when
Text is short labels
Contrast 06 / 10

Contrast in the Sun

High contrast, required for people with low vision, also helps anyone reading a phone in sunlight or a cheap screen at an angle. Meet contrast ratios for all text and controls.

Best for
Text and controls everywhere
Use when
Choosing colors
Avoid when
Purely decorative elements
Language 07 / 10

Plain Language for Every Reader

Writing clearly for people with cognitive disabilities also helps non-native speakers, tired readers, and anyone skimming. Short sentences and familiar words lose nothing for experts.

Best for
Instructions, errors, and policies
Use when
Text explains a task
Avoid when
Specialists need exact technical terms
Caution 08 / 10

Not Just a Business Case

Critics such as legal scholar Blake Reid warn that the curb-cut argument can put disabled people’s needs behind general benefits, and leave out features that only help disabled people. Build accessibility because people need it; the wider benefit is a bonus.

Best for
Accessibility planning and advocacy
Use when
Justifying accessibility work
Avoid when
Broad benefit is the only argument made
✦

The Curb Cut Effect in the Age of AI

Speech recognition, text-to-speech, and image description began as assistive technology. AI has made them everyday features.

✦ AI Era 09 / 10

Assistive Tech Went Mainstream

Voice assistants, live captions, and read-aloud grew out of technology built for disabled people. Keep disabled people in testing as these features change, because they rely on them most.

Shift
Assistive → everyday
Use when
Shipping voice, captions, or descriptions
Watch for
Tuning only for mainstream users
✦ AI Era 10 / 10

Generated Alt Text and Captions

AI can describe images and caption audio at scale, which also helps everyone who searches and skims. Errors land hardest on the people who depend on them, so review generated descriptions of important content.

Shift
Manual → generated
Use when
AI writes alt text or captions
Watch for
Publishing generated alt text unreviewed
Further Reading