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.


For a class I am taking I read the National Resource Defense Council report on Stormwater Strategies: Community Responses to Pollution Runoff.  In that report I happily stumbled upon the following paragraphs (emphasis mine):

Transport imperviousness generally exceeds rooftop imperviousness in urban areas of the United States.5Cumulative figures show that, worldwide, at least one third of all developed urban land is devoted to roads, parking lots, and other motor vehicle infrastructure. In the urban United States, the automobile consumes close to half the land area of cities; in Los Angeles the figure approaches two thirds.”6 The city of Olympia, Washington, also found that transport imperviousness constituted approximately two-thirds of total imperviousness in several residential and commercial areas.7 This distinction is important because rainfall on transportation surfaces drains directly to a stream or stormwater collection system that discharges to a waterbody usually without treatment, whereas some roofs drain into seepage pits or other infiltration devices. Research has also found a strong relationship between curb density and overall imperviousness in residential areas suggesting that roads lead to the creation of other impervious surfaces.8

The creation of additional impervious cover also reduces vegetation, which magnifies the effect of the reduced infiltration. Trees, shrubs, meadows, and wetlands, like most soil, intercept and store significant amounts of precipitation. Vegetation is also important in reducing the erosional forces of rain and runoff. In one study, conversion of forest to impervious cover resulted in an estimated 29 percent increase in runoff during a peak storm event.9

Urban life will always have impervious surfaces, it’s the nature of human settlement.  We cannot possibly achieve runoff totals that mimic life before urban development.  However, that does not mean we cannot plan for the future or current establishments to cut back on the total amount of roads, parking lots, driveways, garages and other automobile related structures.  While railroad tracks exist on firmly packed land and are therefore impervious as well, they also are not the same as asphalt in terms of the type of imperviousness.  Moreover, light rail can exist in green spaces, as in the above picture.

However, the most important part of rail technology is it takes up less space than roads.  The number of people that can travel on a skinny railroad track can mimic the number of people on a busy multi-lane highway.  As I always say, roads are not about to and nor should they disappear.  However, decreasing the number of roads and other auto-dependent land uses would be a boon to the environment.

Runoff is a danger for a number of reason: for the pollutants it carries, for the erosion that occurs, for the way it prevents water from getting back to aquifiers, ground water, and other elements of the watershed.  Decreasing our impervious surface area by relying on rail more and our roads less would be a boon to our cities not just for ecological and economic reasons, but also because it would open up more space for the city to either grow in density or for public space to be available to be used.  Imagine your busy roads now being parks instead!


The National Transportation Safety Board can account to the fact that public transportation is not perfectly safe.  There are occasionally tragic fatalities as the result of accidents on subways, trolleys and buses.  However, when compared to the number of fatalities on America’s roads, public transit appears to wrap passengers in bubble wrap.  For a culture that is obsessed with safety, it is unfortunate that public transportation discussions do not more frequently cover safety.

Our reliance on roads as the primary means of transportation led to 37,261 fatalities in 2008, not to mention however many countless thousands of other injuries were sustained to both person and property.  There have been 419,321 auto-related fatalities over the past decade.  That is like killing off all of Miami, Oakland or Cleveland over the course of a decade.  Keep in mind that people are generally more afraid of flying than driving, but according to the NTSB, ony 706 passengers have died on American flights in this decade.

We all too frequently gloss over the cost of human life when discussing the cost of infrastructure.  If cities and metopolitan areas have the opportunity to devise systems of public transportation that allow more residents to commute to work via train/bus/light rail rather than driving, those opportunities should be taken advantage of.  The cost in human life alone is too much to bear in order to say people should have the freedom to drive.  More importantly, people should have freedom of choice in their means of transportation.  In too many metropolitan areas in this country people are burdened with the necessity of a car.

There are innumerable benefits to public transit, but the human benefit of lives saved or otherwise unaltered by severe injuries, should never be taken lightly.  No transit method is ever free from danger, and that includes the simple act of walking.  However, moving our populaces via mass transit rather than the individually controlled method of the automobile is sure to preserve the sanctity of life going forward.  The more people are on larger systems and the less they must rely on cars the better off both individuals, families, businesses, communities and society will be.


Whether you have lived in a city for years or are visiting one for the first time you probably prefer to take some sort of train when using public transportation.  I believe this is due to the perceived superior reliability, safety and ease of use for trains.  After all, trains are on tracks that only go in two directions and there are defined stops.  Buses are just enormous cars that could go anywhere, even if they supposedly are supposed to go certain places.  However, I think a lot of it has to do with maps.  We are all tube_mapused to the transit maps like that used in London.  It’s a relatively abstract system of lines and colors showing where the various subway trains travel to and where they intersect with each other.

Have you ever seen a bus map like that?  I have not, but that does not mean they do not exist.  Certainly such maps are easier when there is a guaranteed bus line such as bus rapid transit systems, like those in Las Vegas or Hartford.  Systems that have dedicated lanes or demarcated lanes where buses go are much more analagous to light rail.  This is even more true where bus stops have fare gates, such as certain places on Boston’s Silver Line.

The Transportationist (see blogroll) has discussed improving bus signage to make buses more desirable.  I believe this is critical.  Buses are intimidating to the unitiated, becasue unless you’ve ridden one before or are intensely familiar with a neighborhood, where a bus goes and where it stops seem intensely mysterious.  When you enter a subway station on the other hand you usually are shown at least a system map and many times shown a system map overlaid upon a geographic map.  I cannot remember the last time I saw this at a bus stop.

brt_bogotaI recognize the difficulties of producing bus maps; the malleability of bus routes, fluctuation in stops, the lack of permanence of many stops, the challenge of portraying dozens of bus maps on one map.  I agree that to portray every bus route on one map would be beyond chaotic.  However, I believe urban transit systems could begin with their most heavily travelled lines.  Maps should show where buses go, how frequently they travel, how frequently they stop (because if the bus stops every block or two blocks it is not necessary to portary every stop) and where the bus route intersects with other routes and other transit options.  If buses travel on city routes it would also be potentially helpful if lines were painted on the street to show where buses travel.  There is no doubt where trains go, just follow the tracks or the subway stops.  However, it’s not always so clear for buses, especially, if there is no shed or covering at the stop.  Therefore, better signage is required at stops to alert people where they in fact are.  They should be visible from a distance, not small like no parking signs.

Buses have a long history in this country of being portrayed as an undesirable means of transportation.  In the first third of the 20th century General Motors bought out trolley systems across the country and replaced them with bus systems for the twofold reason that they could produce the buses and fewere people want to ride buses than trolleys and would therefore be more likely to drive.  However insidious it was also insightful.  Trains are more desirable than bus lines, but much can be done to improve bus lines such that they are more rider friendly.  Visitors and residents to cities alike should see the bus system as a matter of access, not a burden less worthy of their patronage than rail.


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