Transit planners and lovers wax romantic about the virtues of transit oriented development as well as the potential of current and future urban areas to support successful public transportation.  However, as Yonah Freemark at the Next American City points out, such development is only successful for cities that have sufficient urban density.  Freemark discussed the early 20th century idea and development of streetcar suburbs and why they no longer have their streetcars and whether we will make the same mistakes again with current light rail developments.  (My partner shared this column with me)

Aaron Renn argued last week on the Urbanophile that metropolitan areas with populations of less than about two million inhabitants don’t necessitate the kind of high densities urbanists often promote. Citing the example of Columbus, Ohio, Renn suggested that because these regions are small enough in area to make commuting from one end to the other by car possible within a short amount of time, creating dense, walkable neighborhoods focused around a “huge, packed, downtown core” is not absolutely necessary.

In some ways, his argument rings true: for those driving private automobiles, neighborhoods like the former streetcar suburbs may be ideal. For businesspeople hopping from one side of the region to the other (“to lunch”), driving in medium-sized cities works fine.

On the other hand, for everyone else—the young, the old, the poor, the sick—such neighborhoods provide no alternatives. You can’t easily walk to school or to the store or to the senior center when you live in a streetcar suburb. Nor can transit operators provide adequate service, since densities are too low to make frequent buses possible.

This discussion plays on something conceptually obvious, that to have successful transit there must be a critical mass of people relying on the service or else it is bound to fail.  No government can afford to run buses or trolleys down thoroughfares on a frequent basis when they will be largely empty most of the time. Moreover, with insufficient density and a lack of commercial destinations for residents transit will be underutilized.

However, that idea may not be as obvious as it seems. I cannot count how many times I have been waiting for the Green Line trolley in Boston when I have heard fellow riders complain and wonder out loud why the MBTA is not more like New York’s MTA.  The simple answer is that New York City subways are large, convenient and frequently running because they service a lot of people in a small area in densely populated Manhattan.  Clearly, boarding a trolley with 12 other people in Brookline is incredibly dissimilar from joining hundreds at Columbus Circle.

Therefore, there are many cities that may have large populations that are insufficiently dense to provide the kind of transit service that gives people reason to give up their cars.  In my mind for these borderline and unqualified urban areas there are at least three solutions if transit is to be developed.

1) Local, state and federal policy can encourage zoning changes to allow for greater density before building transit systems.

2) Communities can simultaneously adopt policies restricting the presence of cars per household and/or parking spaces to emphasize transit usage and car sharing.  In this fashion only households which desire to utilize transit will move into these communities, rendering both density and transit-dependent density.

3) Perhaps the least feasible of the ideas, but I will continue to push for pod transit in the suburbs.  I still believe a linkable pod system that utilizes public thoroughfares but simultaneously allows for the malleability of personal motor transit in suburban locations has a reasonable future.

As oil prices go up and American population continues to escalate we will want to develop successful transit systems.  In order to do so we must develop the housing and parking policies that correspond to make both viable.


I have written about pod transportation here many times in the past.  Therefore, I was pleased to see a feature on pods in the Boston Globe on Sunday.  The article did an effective job of communicating the challenges and promise of pod transportation.  There is no debating the upfront cost of such a system and the fact that such personal rapid transit (PRT) systems are not effective everywhere.  However, no means of transportation is effective everywhere.  Try flying a 747 to the grocery store!

That said, I believe there is enormous hope for pod transportation in places that are currently urban but not quite dense enough to support thorough public transportation by bus or light rail.  There are dozens of neighborhoods in every city that are distinctively urban: multi-family housing, integrated commercial and residential property, little open land beyond parks but are not quite suitable for anything but the ubiquitous car.  Such neighborhoods are plagued by the catch that if they established bus service there is not enough ridership to support a bus frequently and if the bus doesn’t run frequently it no longer is convenient. Regardless of the relative costs of transportation, people will always be willing to pay more for convenience and time.  If public transportation cannot compete with private means it cannot be effective.

While some true believers hope PRT will eventually become a dominant mode of transit, others see it more as a gap-filler. It could serve places like airports, university campuses, and medical centers. As a “distributor,” it could branch out into less dense areas to bring riders to other mass transit hubs. And it could provide a valuable service in “edge cities,” to ferry people from residential areas to shopping areas or office parks – routes that are now taken almost exclusively in automobiles.

“We’re typically looking for niche applications,” says Steve Raney of Advanced Transit Systems, the company that is building the system at Heathrow. Likening PRT to “a shuttle bus on steroids,” he says that although it won’t completely obviate the need for cars, “what previously was a two-car family now becomes a one-car family.”

The Globe article suggested elevated tracks, but that is not necessary, as seen at Heathrow airport for parts of its new pod system.

Pod systems are idea for getting people between places highly traveled like a parking lot and an airport or various parts of a neighborhood and major transit hubs.  It is the latter that I think has the most promise.  In an airport parking lot people will accept the option given to them, but when traveling around a neighborhood and to work people make fundamental decisions that affect the environment socially and physically.

I try to remind the readers that the population of the US is going to expand to over 400 million residents by 2050.  These people are going to have to live somewhere and the extent to which we can continue to create suburban and ex-urban communities is peaking or has peaked.  Our urban neighborhoods are our future and creating transit systems that service them appropriately is key to their success.  Pods may be a great solution for making urban neighborhoods denser, more sustainable and importantly less car dependent.

SkyTran Seattle2 - new head final

My friend Greg Moran, who knows a thing or two about infrastructure,  sent me this fascinating link to SkyTran.  The developers of SkyTran describe the product thus:

SkyTran is the Auto 2.0 or Auto2 – not just auto-mobile but auto-matic. This new-generation vehicle holds two passengers and weighs just 200 pounds empty. It moves on lightweight “guideways” one-foot wide and 20-30 feet above the ground, riding on magnetic levitation (“maglev”) coils inside the guideway instead of wheels. Because vehicles floating on a magnetic field can switch on and off the guideway easily, there will be stations every few blocks – or several per block in busy areas – little platforms 10′ above the sidewalk or attached to the side of buildings.

GreenTech Media provides a great illustration of what such a system might look like as well:

For a mental picture, think of a magnetic levitation (maglev) trains cross-bred with that thing that shuffles around shirts in a dry cleaner.

The first lines would be along heavy-duty transportation corridors, i.e., delivering passengers from central downtown stations to the airport, or inside the redesigned city of the future. Over time, the lines could be extended to individual homes with parallel tracks for exits. The cable required to propel the vehicle and hold them in the air is only about 18 inches wide and two feet wide, said John Cole, Unimodal’s COO.

“You could install it on standard utility poles. It would require the same gauge [of pole] that would hold up a traffic light,” he said.


Can you imagine an America without cars?

An America that thrives solely on public transportation?  A nation where rails criss-cross the land and the asphalt is ripped up?  Truthfully, I cannot either.  The American landscape is too vast for us to ever believe the population will be solely concentrated in urban centers or could ever depend solely on parallel steel lines.  However, the tide is shifting back toward the cities, but the suburbs close to the urban core will always survive.  Americans love having options for their domestic lifestyle, and many will always choose to have sprawling lawns, lower population density, and the ability to have property that they can care for.  We should not deride people for that decision with LeCorbusierian disdain.  Rather, we must plan our transportation infrastructure to include these people as well, even if the challenge is greater than simply creating subway lines and bike lanes.  What if we could do away with the car without subtracting the freedom of movement the automobile has allowed?

I would like to suggest that we can accomplish this by creating a pod system for our less dense urban and suburban areas.  In order to transport individuals to and from our urban cores we currently expect most people to drive.  Yet many use a largely inefficient system of buses and rail lines with various stations that people walk or drive to.  What if we did away with the transfer of transportation modes at the bus stop?  What if rather than getting out of your car and waiting for the train your car became the train?  I imagine a system designed where pods would be independently operated as well as modules to be linked in a larger train.  In this system individuals would have the ability to traverse the meandering streets outside the urban core and the ability to get toward the center of commerce with one vehicle.

The pods could be much like today’s rail service cars with rubber street tires and a set of rail wheels that can be set down.  Or the system could run much like some of Paris’s subways which all have rubberized wheels to begin with.  The pods would link to each other and be operated along a set of tracks and pulled by an independently operated engine.  Or maybe the modules can link up to an electro-magnetic system or have pantographs to ride along like most city trolleys.  The advantage to this system is of course the energy efficiency provided by mass transit juxtaposed with a vehicle that still provides individuals freedom of movement in areas that are not amenable to larger vehicles.  Individuals or commuter groups could fill in to a pod at the city center and ride it out to their varied stops and disconnect from the greater chain.  At this point the train would condense and proceed to do so until it got to the end of the line.

There would be two modes of pod transit, those who drive the pods, and those who merely want a ride.  There may be individuals who want to ride the pods but feel they do not need the mobility of driving them.  Therefore they may just catch a ride in a pod with an empty seat.  More people or neighbors are likely to subscribe to a pod lease of some sort such that they will have access to one at all times.  However, at no time would a person just keep one pod.  The passengers would drive their pods to the train station, link up, and get off at their destination in the city.  However, it is counter-intuitive to have all these pods buzzing around densely populated urban streets—if anything we should seek to eliminate cars from the urban scene.  Rather those going the other direction would have access to the pods that had been brought in and those that were not needed would wait in a holding dock until rush hour for the commute back out of the center.

Yet I also acknowledge the need for multiple types of pods.  A pod that only has three seats will not suffice for a family of five.  Therefore pods will either have to come in different arrangements of seats or the empty seats in a pod will have to be filled by commuters who walk to the linking stops.  Another solution is for pods to be used like car pools currently are such that they are used most efficiently, for empty seats in pods creates far more energy demand on both the number of pods driving and the number that must be pulled.  However, this system also allows for pods to be kept in driveways while not being used for mass transit purposes.  Therefore the state would need to finance enough pods potentially for each household or proportional to car use in suburban areas.  Pods are not the solution to the car, for to use them effectively they will inherently lack storage space and distance capabilities.  However, the pods could act much like today’s Smart Cars, effective for small trips in cities, easy to park, capable of carrying small goods and a number of people, and energy efficient.

The optimal design for the pods is up to our imagination (perhaps the air car is the pod of the future).  I’ve debated having them round, but I believe they should be designed much like cars, all the seats facing one direction, so that they do not encounter any problems when utilized as cars are today.  However, shape and arrangement of seats, engine, and storage space is definitely up for grabs.  How the pods link and detach at various stops is also to be determined.  Clearly the process should be as efficient as possible.  I imagine local stops having asphalt level rails such that the pods can detach and merely roll away without having to be removed from rails.  Perhaps at the station in the city the pods will have an LCD sign inside or a label on the station platform stating where the pod will detach.  This way even if the pod isn’t full it will detach at the station of destination and be available for use in that town.

The public transportation system for our suburbs is not intractable, it just requires some innovative thinking and large investments.  This would be a great investment for a city that is already used to a car sharing project such as Zipcar given that pods would not be personally owned.  The goal would  be to keep pods in service for long periods of time and make them incredibly efficient, relying on alternative energy sources.  This would be a boon to American industry, construction of new lines, investment in alternative energy, the design and production of pods, and of course new jobs for upkeep and improvements to a new system of transportation.  While the lights in Detroit may be flickering the future of American transportation could be bright!

To any followers of the Transit Pass, welcome back!