A video explainer of the notorious traffic law that explains why some cities have to raise speed limits to enforce traffic safety.
To understand the scale of the challenge that must be overcome to achieve Vision Zero safety goals to eliminate traffic fatalities and to break the strangle hold cars have on U.S. cities, look no further than the 85th Percentile Rule, as neatly explained in the Grist video shown above.
For more background, see past Planetizen coverage of the 85th Percentile Rule.
FULL STORY: A 1930s city planning rule has drivers setting their own speed limits

Maui's Vacation Rental Debate Turns Ugly
Verbal attacks, misinformation campaigns and fistfights plague a high-stakes debate to convert thousands of vacation rentals into long-term housing.

Planetizen Federal Action Tracker
A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

In Urban Planning, AI Prompting Could be the New Design Thinking
Creativity has long been key to great urban design. What if we see AI as our new creative partner?

King County Supportive Housing Program Offers Hope for Unhoused Residents
The county is taking a ‘Housing First’ approach that prioritizes getting people into housing, then offering wraparound supportive services.

Researchers Use AI to Get Clearer Picture of US Housing
Analysts are using artificial intelligence to supercharge their research by allowing them to comb through data faster. Though these AI tools can be error prone, they save time and housing researchers are optimistic about the future.

Making Shared Micromobility More Inclusive
Cities and shared mobility system operators can do more to include people with disabilities in planning and operations, per a new report.
Urban Design for Planners 1: Software Tools
This six-course series explores essential urban design concepts using open source software and equips planners with the tools they need to participate fully in the urban design process.
Planning for Universal Design
Learn the tools for implementing Universal Design in planning regulations.
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