50mph Speed Limit Would Cut CO2 By 30%, Says New Study

Reducing the speed limit to 50 mph, say researchers, would create the tipping point where taking transit or modes other than driving will become more attractive and therefore save CO2 emissions.

1 minute read

June 13, 2010, 1:00 PM PDT

By Tim Halbur


Also, it turns out that driving slower reduces emissions.

From Wired: "The faster you go, the more fuel you burn because wind resistance increases exponentially. Lowering your speed by 5 mph when traveling at 35 to 45 mph will boost fuel economy as much as 10 percent (.pdf), according to a report the General Accounting Office prepared in 2008."

Treehugger takes the Wired article a step further, presenting six reasons why slowing down is beneficial. For one:

"It could save a lot of fuel. Some estimates indicate up to 5%; In 1983, by which time many people were ignoring it, it saved 2.5 billion gallons of gasoline and diesel, or 2.2% of the total fuel used. Oil was a horrible $ 20 per barrel. Wired notes that "The Department of Energy noted in 2008 that lowering the national speed limit to 55 mph would save 175,000 to 275,000 barrels of oil daily."

Wednesday, June 9, 2010 in Wired

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.

3 hours 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.

4 hours 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.

5 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.

Senior Manager Operations, Urban Planning

New York City School Construction Authority

Building Inspector

Village of Glen Ellyn

Manager of Model Development

Central Transportation Planning Staff/Boston Region MPO