Urban Transportation's Four Separate Challenges

At the Shared Use Mobility Summit in Chicago, Jarrett Walker cautioned the tech world to keep four key transportation problems in mind.

1 minute read

April 3, 2018, 5:00 AM PDT

By Philip Rojc @PhilipRojc


Jeff McMahon sums up transit expert Jarrett Walker's comments at the National Shared Mobility Summit held in March. "Walker argued that technology can solve some problems, but not the same problem that public transit solves." 

McMahon references a memorable Twitter spat between Walker and Elon Musk in which the Tesla founder criticized typical modes of transit and insulted Walker directly. At the summit, Walker called attention to "four separate problems of urban transportation which have four separate kinds of solutions," further arguing that "it is very important to not mistake the solution for one problem for the solution for a different problem."

The list includes 1) communications and real time information, for which digital tech has proven useful; 2) emissions and energy efficiency; 3) labor and safety; and 4) the amount of urban space different modes take up. 

Walker argued that "The fixed-route bus or train is the vehicle of the future [...] because it remains the most efficient way to move large numbers of people through the congested space of a city."

Monday, March 19, 2018 in Forbes

Young Professional

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 and Environmental 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 and Environmental Planner

Get top-rated, practical training for planners

Overlapping highways

The state-sanctioned urbicide of Austin

People don’t kill cities. Freeways do.

September 8, 2026 - Benjamin Schneider

The Hoover Dam blocking the Colorado River. The river's water level is noticeably low. The cliffs surrounding the blue water are brown and jagged.

US to reduce Colorado River water deliveries to Mexico

A new Colorado Treaty amendment reduces Mexico’s Colorado River water allocation by 250,000 acre feet.

September 11, 2026 - The Arizona Republic

Skyscrapers in Jersey City.

New Jersey’s second-largest city bans standalone data centers

Jersey City will continue to allow co-location facilities, such as those meant for research institutions that store their own data.

September 4, 2026 - The Cool Down

A New Jersey train approaches people waiting at the station.

Amtrak not solely to blame for New Jersey commuter rail's unreliability, report finds

A new study from the Garden State Initiative found that NJ Transit’s budget grew 20% across a 4 year period, but reliability declined significantly over the same period.

September 15 - Mass Transit

A tall, gray power plant billows smoke into a blue sky.

EPA erases limits on planet-warming pollution from power plants

Under Monday’s plan, power plants would still have some limits on how much mercury, arsenic and other contaminants they can emit.

September 15 - New York Times

A white RAPID bus. The lower half is light blue, and says RAPID in purple text. The bus is half visible, appearing from the left side of the image.

Phoenix announces new on-demand transit service, more frequent RAPID buses

Both new services will launch in October, and are part of Phoenix's Project Effective Access Solutions for Easing Congestion.

September 15 - KJZZ

FREE Course: Walkable City 1: Why Walkability?

After describing his path towards focusing on walkability as the essence of good planning, Jeff Speck marches through his five principal reasons for making more walkable places.

Reinventing Malls: Planning Alchemy—Turning Gray Fields Into Gold

The course focuses on the opportunities and imperatives that shape reinvention of mall sites.