What mobility really means

Michael Lewyn's picture

Every so often, I read a blog post or an article talking about the trade-off between "mobility" and making places more accessible to nonmotorists.  The hidden assumption behind such statements is that "mobility" means cars going as fast as possible.  So if every street is an eight-lane highway with cars going 70 miles per hour, overall social "mobility" is therefore high. 

The use of the word "mobility" to describe fast traffic slants public dialogue in favor of such traffic: after all, who could be against people being mobile? 

But we need not define mobility this way. According to one online dictionary I found, "mobility" means (among other things) "the movement of people in a population, as from place to place."*

In a sprawling city where most streets are designed for fast traffic, the mobility of some people (fast drivers) is undoubtedly very high.  But the mobility of others is not.  In such places, streets are dangerous and uncomfortable for pedestrians- which means that in fact, nondrivers cannot easily move from place to place and are thus not so mobile after all.  And even the mobility of drivers is limited: they can be mobile as long as they are driving, but if they choose not to drive for some reason, their mobility disappears.

Thus, government construction of wide, automobile-oriented streets does not create mobility for all.  Instead, automobile-dependent places actually eliminate mobility for nondrivers.  It logically follows that mobility for all is highest in places that accommodate pedestrians, transit users, and bicyclists as well as drivers- in other words, that accessibility is mobility.



Michael Lewyn is an assistant professor at Touro Law Center in Long Island.



Ian Sacs's picture


thanks for writing this michael. i'm constantly workign with auto-centrics who only equate their modal choice to mobility, ther should be a guide book for professionals on how to respond to these kinds of "slants in public dialogue" without looking like semantic-freaks. cheers! -ian

Access to Destinations

I assume that you are familiar with the 'Access to Destinations' study being run at the University of Minneosota? They emphasize that the concept of mobility - the ability to move around - is distinct from that of accessibility, and it is really this 'access to destinations' which is the important measure which we should be considering.

You can find more information about their study here:

Mobility Versus Access

Agreed, mobility is not the same as access to destinations. Access is more important than mobility.

In the United States, per capita VMT doubles every few decades. That means the mobility of the society as a whole is increasing dramatically. But we all know that people are not necessarily better off because of this greater mobility. Suburbs sprawl at such low densities that people have to drive twice as far to get where they need to go.

Here is an obvious example that we are all familiar with. Low-density zoning drives up the price of housing near the center of a metropolitan area. As a result, people can only afford to buy houses far out on the suburban fringe, and the state highway dept. builds freeways to these new suburbs. The suburbanites have to commute twice as far as they would with zoning that let them live closer to the center. In other words, they are much more mobile than they would be with different zoning, but they are not better off.

I think we should go further than Michael's redefinition of mobility, which says we must increase mobility for pedestrians as well as for drivers. Instead, we should say that increased mobility is not necessarily a good thing. If people have to be mobile because they do not have convenient access, then that mobility is a burden rather than a benefit.

Charles Siegel

Mobility as transport evolution

Thank you for addressing this concept in a public forum.

My definition of mobility: transport system evolution that enhances the quality of life, not the progress of disjointed parts (automobiles, trains, bicycles, shoes).

A linguistic problem?

It would be fascinating to dissect all transportation sections from Wikipedia, to analyze the language and map it.

For example, in the Santa Barbara transportation section:
Before: "Santa Barbara is bisected by U.S. Route 101, a PRIMARY transportation corridor that links the city to the rest of the Central Coast region."
After: "Santa Barbara is bisected by U.S. Route 101, an AUTOMOTIVE transportation corridor that links the city to the rest of the Central Coast region."

Note also that automotive transport is placed first in the paragraph, a sign of bias towards automobiles.

I want to use this concept for an art project. Any ideas of who could sponsor?

SoCal vs. NorCal transport

Another example from Wikipedia - compare southern and northern California pages. Great insight on the regional transportation values.

Southern California: http://en.wikipedia.org/wiki/Southern_California#Transport
Northern California: http://en.wikipedia.org/wiki/Northern_California#Transportation

Level of Service

The concept of "Level of Service" also ties into this. We have to start thinking of Level of Service in terms of people throughput, instead of automobile throughput.

Re-Framing the debate

This thought is not mine originally, but I can't remember where I read it; often we hear of road "improvements" that always mean more lanes, higher travel speeds, etc. Then there are road "hazards" which is, here in central LA, often the way pedestrians and children are referred to.

When I was helping with the SundayStreets projects in San Francsico, we made a strong point of describing the event not as a street closure but as a street opening, and I can remember having to discipline myself when telling people about the project; "the streets are open, OPEN, not closed," I would say in my head.

Because we are all working against an ubiquitous monoculture, one that has affected all levels of even how we think about moving ourselves, we need to employ that same discipline I learned that summer, constantly making the point to ourselves and others that streets are FOR PEOPLE, that they are our most abundant PUBLIC SPACES and that mobility is a nearly useless metric in urban environments without equal consideration for access.

See Growing Power

"Accessibility is mobility." Conceptually, that helps me think of the equity, access and land use questions as much as the transportation questions. we should frame mobility solutions by addressing physical infrastructure needs in line with social and economic needs. For example, the fact that healthy food options do not avail themselves readily in concentrated areas of poverty (at affordable prices and at distances that would allow the easy transport of groceries) is an issue of mobility. Those kind of problems may be addressed in any number ways. Note that exploitative industries take advantage of the gaps in accessibility and as such would have a vested interests in preserving the gaps. Organizations such as Will Allen's Growing Power are offering mobility solutions by removing such gaps.

Public space

One way to make the underlying assumptions of car-culture clear to people: measure how much of a town or city's area is devoted to car travel. My small city's 318 miles of roadway account for close to 10% of the total land area, and a much higher percentage of public space. (I haven't included parking lots in my calculations because many of those aren't public space.) If you have people estimate how much public land in their town is potentially lethal to people walking, they might be surprised at proportions like 50%. We need to re-think how we use public space. Roads are part of public, shared space: it's just that the use of them is highly specific to motorized vehicle travel. I don't think there's any other major public space that has such a narrow spectrum of use.

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