Human Transit

How Clearer Thinking about Public Transit Can Enrich Our Communities and Our Lives

Jarrett Walker

• Éditeur: Island Press
• Année: 2012
• ISBN:
  9781610911740
• Sujet: Tecnologia e ingegneria
• Sous-sujet: Trasporto e navigazione

Public transit is a powerful tool for addressing a huge range of urban problems, including traffic congestion and economic development as well as climate change. But while many people support transit in the abstract, it's often hard to channel that support into good transit investments. Part of the problem is that transit debates attract many kinds of experts, who often talk past each other. Ordinary people listen to a little of this and decide that transit is impossible to figure out.Jarrett Walker believes that transit can be simple, if we focus first on the underlying geometry that all transit technologies share. In Human Transit, Walker supplies the basic tools, the critical questions, and the means to make smarter decisions about designing and implementing transit services. Human Transit explains the fundamental geometry of transit that shapes successful systems; the process for fitting technology to a particular community; and the local choices that lead to transit-friendly development. Whether you are in the field or simply a concerned citizen, here is an accessible guide to achieving successful public transit that will enrich any community.

1

WHAT TRANSIT IS AND DOES

There are several ways to define public transit,^a so it is important to clarify how I’ll be using the term. Public transit consists of regularly scheduled vehicle trips, open to all paying passengers, with the capacity to carry multiple passengers whose trips may have different origins, destinations, and purposes.

Let’s take this definition apart:

• “regularly scheduled vehicle trips”: Transit is provided by a vehicle running on a regular schedule or pattern. There is room for variation in routes and schedules. Demand-responsive services, for example, may vary their routing according to customer requests, within set limits. But at its core, transit service must be predictable so that different people can plan around it without coordinating directly with one another. This feature is the crucial difference between transit and other ways of sharing a ride.
• “open to all paying passengers”: The word public in public transit means “open to the entire public.” This word can be confusing in debates about whether transit should be operated by the government or by the private sector. In the developed world, where wage costs are high, transit is usually subsidized by government, but it may still be operated either by government or by private companies. In those conversations, public transit can be misunderstood as meaning “transit operated by the public sector—that is, government—rather than by private companies.” That is not the meaning in this book or the prevalent meaning in the developed world. Even privately operated transport services are expected to welcome all paying customers; in fact, the failure to do so can become a civil rights issue.^b
• “that can carry multiple passengers”: The ability to carry many people with a single vehicle is the defining virtue of transit, and the most basic measure of its efficiency.
• “whose trips may have different origins, destinations, and purposes”: Transit, in the sense used in this book, does not include:
  • ° carpools and vanpools, where several people with the same destination share a ride;
  • ° school buses, where school is the only origin or destination served;
  • ° a family in their minivan, or any other group that’s intentionally traveling together;
  • ° taxis, which carry a small number of riders at the time, typically all with the same origin and destination.^c

There are many forms of multi-occupant vehicles, all of which are better for the environment than the same individuals each driving alone. Carpools, school buses, and shared taxis are all useful parts of a city’s transportation mix, and sometimes demand can be shifted between these services and the formal public transit system. But they are not public transit as this book, and most of the industry, uses the term.

At its core, transit is about multiple people riding in one vehicle even though they are not intentionally traveling together or even going to the same places. The core challenge of transit design, then, is how to run vehicles so that people with different origins, destinations, and purposes can make their trip at the same time and will be motivated to choose transit to do so. This book is all about that challenge.

TRANSIT’S ROLE IN A COLLABORATION OF MODES

While this book is about transit, I never imply that transit is or should be the dominant alternative to the private car. Many ways of sharing vehicles have important roles to play in the larger project of reducing car dependence. These include many forms of carpooling and vanpooling, which typically carry people from a similar area of origin to a common destination, as well as “carshare” programs, which provide members with hourly self-service car rental, thus reducing a household’s need to own cars. These programs, commonly supported by transit agencies,^d are important complements to transit, though they are not this book’s focus.

In focusing on transit, I am also not denying the role of the “active modes,” such as cycling and walking. Quite the opposite. Virtually every transit rider is also a pedestrian, so transit ridership depends heavily on the quality of the pedestrian environment where transit stops.^e The ability and willingness of people to walk a short distance to a stop or station is what makes it possible to gather many people with many intentions on a single vehicle, which is the essence of transit’s project.

Cycling, meanwhile, is growing rapidly in many New World cities, at least those that have made some effort to accommodate it. But even in the most bicycle-dominated countries, such as the Netherlands, transit has a crucial market. Local bus service has a somewhat smaller role there because bicycles take so much of the short-distance market, but in the longer-distance market, trips over 3 miles (5 km)^f or so, cycling and transit reinforce each other. Longer-distance “rapid transit” services (rail and bus) run fast by not stopping often, but their stations feature masses of bicycle parking. The bicycle becomes an ideal tool for extending the reach of a rapid transit station, reducing (but not eliminating) the need for slower local bus and streetcar services.

Many cities and transit agencies are looking at how to expand the potential for these “cycle + transit” trips. These efforts include enhancing bicycle storage opportunities at stations as well as allowing cyclists to bring their bikes onboard, at least during low-demand times when there’s room to spare. These strategies have the potential to build the market for both cycling and public transit.

So transit has the potential for a mutually beneficial relationship with most of the other alternatives to the private car.

• Walking is an intrinsic feature of almost all transit trips, so all transit advocates must be pedestrian advocates. Transit outcomes depend heavily on the nature of the walking required, including both how long the walk is and how pleasant it is.
• Cycling can compete with local transit but tends to complement longer-distance rapid transit, especially when investments are made in secure bicycle storage at stations.
• Carpooling is a crucial tool for regularly scheduled commutes, especially to lower-density employment centers, such as business and industrial parks, that are not dense enough to attract high-quality transit.
• Carsharing, a form of short-term car rental, is essential in cities that want to encourage lower levels of car ownership, at least in their denser neighborhoods where the space requirements of private cars are hardest to meet. Carsharing eliminates the temptation to own a car that you only need once or twice a week, by providing the cheaper option of shared cars for these purposes.

So even as these other sustainable transport modes grow, we will need public transit. Among the sustainable transportation alternatives, public transit is unique in two crucial respects. First, only public transit can carry large numbers of people in a single vehicle with a single driver,^g even as these people travel from different origins to different destinations for different purposes. At the intense levels of demand found in high-density cities, public transit is an efficient use of both energy and scarce urban space and is often the most attractive option for trips that are too long to walk or cycle.

Second, public transit delivers people from one part of the city to another as pedestrians, eliminating all the challenges of storing a personal vehicle. The pedestrian is the foundation of contemporary urban design, because walking is the only form of transportation that doesn’t feel like transportation at all. Walking is also an ideal mode for both health and sustainability. If you want to encourage pedestrian life, you need to connect pedestrian-intensive places to one another in a way that the pedestrian can use. Transit can be ideal for this purpose.

FIXED OR FLEXIBLE?

To make a vehicle trip useful to many people who are not coordinating with one another, the vehicle trip has to be predictable. That’s why, in the developed world, transit is dominated by fixed services; on these, transit vehicles follow the same path, at the same time, day after day, so that customers can plan around the pattern. Fixed services are the most efficient form of transit in terms of the ability to carry many passengers for each hour of the driver’s time, so they have come to represent well over 99 percent of transit ridership in the United States.

The rest, accounting for less than 1 percent of ridership, are various kinds of flexible or demand-responsive services, where the routing followed by a transit bus or van can change based on customer requests. Although flexible route services are an area of great innovation, they remain limited because they’re intrinsically less efficient. Taking a different route depending on customer requests, as flexible routes do, takes more of the driver’s time for each passenger’s needs. So flexible routes tend to be useful where the overall demand is low, or for specific populations whose needs aren’t met by fixed services, such as some disabled persons. I’ll return to this issue in chapter 10, but for now let’s focus on the services that the other 99 percent ride: the fixed services.

Figure 1-1 Walkscore.com online travel time map showing the area reachable by transit from a user-specified location in a user-specified period of time. Bands represent 15-minute intervals. Source: Walkscore.com

PERSONAL MOBILITY: THE FREEDOM TO MOVE

In 2009, we began to see web-based tools that allow you to enter an address and see where you can get to from there on transit in a fixed amount of time. Figure 1-1, for example, is the output from WalkScore.com when queried by someone near the San Francisco Civic Center at 9:00 am.¹

These tools aren’t for planning a trip; rather, they’re for visualizing your freedom. That freedom is transit’s product. The core product that arises from transit is personal mobility, by which I mean the freedom to move beyond your walking range. Mobility is a controversial concept, so it’s worth taking a moment to clarify how I’ll use the term and why. Readers who are less interested in theory may skip the rest of this chapter, but anyone who thinks theoretically about transportation or urbanism will find this section crucial.

More on Personal Mobility

For more thorough discussion of the concept of personal mobility and how it relates to prevailing concepts of mobility and access in urban planning theory, see http://www.humantransit.org/01box.html.

A quick survey of definitions of mobility turns up a range of slightly different ones, indicating some ambiguity in the word. Here are a few:

The condition of moving freely.²

Ease of moving about.³

Movement of people or goods within the transportation system.⁴

By defining the term personal mobility as a freedom, I mean something close to “ease of moving about,” but this is not at all the same as movement. The first describes a degree of freedom, while the second is a result of some people choosing to exercise that freedom.

If you think of person movement as transit’s product, as many conventional measures do, the output of transit that matters is passenger-miles or passenger-kilometers. A passenger-mil...