It's Time To Reconsider How Speed Limits Are Set

Speed limits are currently determined by a calculation that considers only the status quo of vehicular velocity. Standard practices for speed limit setting and legislators should prioritize the safety of community members, according to this article.

2 minute read

August 9, 2020, 11:00 AM PDT

By Lee Flannery @leecflannery


Hyperloop

Melpomene / Shutterstock

Tiffany Chu, founder of transportation company Remix, asserts that American we need to rethink the way we set speed limits in the United States. While transportation laymen may hope that speed limits are set by a calculation determining the safest rules for traveling by car in a given space, the reality it that safety considerations are simply not a part of the calculation. Instead, says Chu, speed limits are set "by the speed at or below which 85 percent of the motorists drive on a given road, an outdated guideline promoted by the Federal Highway Administration (FHWA)."

Chu reminds that speeding has played a part in about a third of traffic collision fatalities in the United States over the past two decades and that, given these statistics, government agencies need to revise the methods for setting speed limits and introduce speed-reducing street design mechanisms on busy roadways.

For Chu, design is at the center of the solution, pointing to a July report released by the National Association of City Transportation Officials (NACTO), which advocates for speed limits set by criteria like density and activity level in addition to designing slow zones. "We cannot usher in a multimodal future without lowering speeds and making streets safe for all users. We must support the work of those undoing harmful legacy methods, and encourage the adoption of policies that embrace and emphasize design," advises Chu.

Thursday, August 6, 2020 in Forbes

portrait of professional woman

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban Planner

Get top-rated, practical training

Concrete Brutalism building with slanted walls and light visible through an atrium.

What ‘The Brutalist’ Teaches Us About Modern Cities

How architecture and urban landscapes reflect the trauma and dysfunction of the post-war experience.

February 28, 2025 - Justin Hollander

Complete Street

‘Complete Streets’ Webpage Deleted in Federal Purge

Basic resources and information on building bike lanes and sidewalks, formerly housed on the government’s Complete Streets website, are now gone.

February 27, 2025 - Streetsblog USA

Green electric Volkswagen van against a beach backdrop.

The VW Bus is Back — Now as an Electric Minivan

Volkswagen’s ID. Buzz reimagines its iconic Bus as a fully electric minivan, blending retro design with modern technology, a 231-mile range, and practical versatility to offer a stylish yet functional EV for the future.

March 3, 2025 - ABC 7 Eyewitness News

View of mountains with large shrubs in foreground in Altadena, California.

Healing Through Parks: Altadena’s Path to Recovery After the Eaton Fire

In the wake of the Eaton Fire, Altadena is uniting to restore Loma Alta Park, creating a renewed space for recreation, community gathering, and resilience.

March 9 - Pasadena NOw

Aerial view of single-family homes with swimming pools in San Diego, California.

San Diego to Rescind Multi-Unit ADU Rule

The city wants to close a loophole that allowed developers to build apartment buildings on single-family lots as ADUs.

March 9 - Axios

Close-up of row of electric cars plugged into chargers at outdoor station.

Electric Vehicles for All? Study Finds Disparities in Access and Incentives

A new UCLA study finds that while California has made progress in electric vehicle adoption, disadvantaged communities remain underserved in EV incentives, ownership, and charging access, requiring targeted policy changes to advance equity.

March 9 - UCLA Luskin Center for Innovation