Optical Illusion Speed Bumps Tested in Philadelphia

Optical illusions painted on the streets of Philadelphia are being tested out as a method for getting drivers to slow down.

1 minute read

June 21, 2008, 7:00 AM PDT

By Nate Berg


"The fake speed humps are being installed at 100 junctions around Philadelphia, Pennsylvania as part of a campaign against aggressive driving."

"'The goal is to change the mindset,' said Philadelphia's chief traffic engineer Charles Denny."

"'The driver sees this in the roadway, and they think that it's some protrusion up out of the roadway, and not a perfectly flat surface. So they slow down before they drive over it.'"

"Accident data will be collected by the National Highway Traffic Safety Administration to see if the pioneering scheme actually does make the roads safer."

Thanks to Streetsblog

Thursday, June 19, 2008 in Telegraph

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

Logo for Planetizen Federal Action Tracker with black and white image of U.S. Capitol with water ripple overlay.

Planetizen Federal Action Tracker

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

April 30, 2025 - Diana Ionescu

Close-up on Canadian flag with Canada Parliament building blurred in background.

Canada vs. Kamala: Whose Liberal Housing Platform Comes Out on Top?

As Canada votes for a new Prime Minister, what can America learn from the leading liberal candidate of its neighbor to the north?

April 28, 2025 - Benjamin Schneider

Hot air balloons rise over Downtown Boise with the State Capitol building visible amidst the high rises.

The Five Most-Changed American Cities

A ranking of population change, home values, and jobs highlights the nation’s most dynamic and most stagnant regions.

April 23, 2025 - GoodMigrations

People biking along beach path with moored ship in San Diego, California.

San Diego Adopts First Mobility Master Plan

The plan provides a comprehensive framework for making San Diego’s transportation network more multimodal, accessible, and sustainable.

45 minutes ago - SD News

Sleeping in Public

Housing, Supportive Service Providers Brace for Federal Cuts

Organizations that provide housing assistance are tightening their purse strings and making plans for maintaining operations if federal funding dries up.

1 hour ago - KSL

Conductor walks down platform next to Amtrak train at station in San Jose, California.

Op-Ed: Why an Effective Passenger Rail Network Needs Government Involvement

An outdated rail network that privileges freight won’t be fixed by privatizing Amtrak.

2 hours ago - Streetsblog USA

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.