Transportation planning is a field involved with the evaluation, assessment, design and siting of transportation facilities (generally streets, highways, footpaths, bike lanes and public transport lines).
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Transportation planning historically has followed the rational planning model of defining goals and objectives, identifying problems, generating alternatives, evaluating alternatives, and developing plans. Other models for planning include rational actor, transit oriented development, satisficing, incremental planning, organizational process, and political bargaining.
However, planners are increasingly expected to adopt a multi-disciplinary approach, especially due to the rising importance of environmentalism. For example, the use of behavioral psychology to persuade drivers to abandon their automobiles and use public transport instead. The role of the transport planner is shifting from technical analysis to promoting sustainability through integrated transport policies.[1]
In the United Kingdom transport planning has traditionally been a branch of civil engineering. In the 1950s and 1960s it was generally believed that the motor car was an important element in the future of transport as economic growth spurred on car ownership figures. The role of the transport planner was to match motorway and rural road capacity against the demands of economic growth. Urban areas would need to be redesigned for the motor vehicle or else impose traffic containment and demand management to mitigate congestion and environmental impacts. These policies were popularised in a 1963 government publication, Traffic in Towns. The contemporary Smeed Report on congestion pricing was initially promoted to manage demand but was deemed politically unacceptable. In more recent times this approach has been caricatured as "predict and provide" – to predict future transport demand and provide the network for it, usually by building more roads.
The publication of Planning Policy Guidance 13 in 1994 (revised in 2001),[2] followed by A New Deal for Transport[3] in 1998 and the white paper Transport Ten Year Plan 2000[4] again indicated an acceptance that unrestrained growth in road traffic was neither desirable nor feasible. The worries were threefold: concerns about congestion, concerns about the effect of road traffic on the environment (both natural and built) and concerns that an emphasis on road transport discriminates against vulnerable groups in society such as the poor, the elderly and the disabled.
These documents reiterated the emphasis on integration:
This attempt to reverse decades of underinvestment in the transport system has resulted in a severe shortage of transport planners. It was estimated in 2003 that 2,000 new planners would be required by 2010 to avoid jeopardising the success of the Transport Ten Year Plan [1].
During 2006 the Transport Planning Society defined the key purpose of transport planning as
The following key roles must be performed by transport planners:
Transportation planning in the United States is in the midst of a shift similar to that taking place in the United Kingdom, away from the singular goal of moving vehicular traffic and towards an approach that takes into consideration the communities and lands which streets, roads, and highways pass through ("the context"). More so, it places a greater emphasis on passenger rail networks which had been neglected until recently. This new approach, known as Context Sensitive Solutions (CSS), seeks to balance the need to move people efficiently and safely with other desirable outcomes, including historic preservation, environmental sustainability, and the creation of vital public spaces.
The initial guiding principles of CSS came out of the 1998 "Thinking Beyond the Pavement" conference[6] as a means to describe and foster transportation projects that preserve and enhance the natural and built environments, as well as the economic and social assets of the neighborhoods they pass through. CSS principles have since been adopted as guidelines for highway design in federal legislation.[7] Also, in 2003, the Federal Highway Administration announced that under one of its three Vital Few Objectives (Environmental Stewardship and Streamlining) they set the target of achieving CSS integration within all state Departments of Transportation by September 2007.[8] The recent pushes for advancing transportation planning has led to the development of a professional certification program, the Professional Transportation Planner, to be launched in 2007.
In recent years, there has been a movement to provide "complete" transportation corridors under the "complete streets" movement. In response to auto-centric design of transportation networks, complete streets encompass all users and modes of transportation in a more equitable manner.[9] The complete streets movement entails many of the CSS principles as well as pedestrian, bicycle and older adult movements to improve transportation in the United States.
Most regional transportation planners today employ what is called the rational model of planning. The model views planning as a logical and technical process that uses the analysis of quantitative data to decide how to best invest resources in new and existing transportation infrastructure.[10]
Since World War II, this attitude in planning has resulted in the widespread use of travel modeling as a key component of regional transportation planning. The models’ rise in popularity can also be attributed to a rapid increase in the number of automobiles on the road, widespread suburbanization and a large increase in federal transportation spending in urban areas. All of these phenomena dominated the planning culture in the late 1940s, 1950s and 1960s. Regional transportation planning was needed because increasingly cities weren’t just cities anymore, but parts of a complex regional system.[11]
The process, according to Johnston (2004) and the FHWA and FTA (2007), generally follows a pattern that can be divided into three different stages. Over the course of each of three phases, the metropolitan planning organization (MPO) is also supposed to consider air quality and environmental issues, look at planning questions in fiscally constrained way and involve the public. In the first stage, called preanalysis, the MPO considers what problems and issues the region faces and what goals and objectives it can set to help address those issues. During this phase the MPO also collects data on wide variety of regional characteristics, develops a set of different alternatives that will be explored as part of the planning process and creates a list of measurable outcomes that will be used to see whether goals and objectives have been achieved. Johnston notes that many MPOs perform weekly in this area, and though many of these activities seem like the “soft” aspects of planning that aren’t really necessary, they’re absolutely essential to ensuring that the models used in second phase are accurate and complete .[11]
The second phase is what’s called the technical analysis phase. The process is pretty involved and there is lot of technical maneuvering going on, but basically the development of the models can be broken down as follows. Before beginning, the MPO collects enormous amounts of data. This data can be thought of as falling into two categories: that which concerns the transportation system and that which concerns the adjacent land use. The best MPOs are constantly collecting this data.[11]
The actual analysis used is called the Urban Transportation Modeling System (UTMS), though it is often referred to as the four-step process. As its nickname suggestions, UTMS has four steps: trip generation, trip distribution, mode choice and trip/route assignment. In trip generation, the region is subdivided into a large number of smaller units of analysis called traffic analysis zones (TAZs). Based on the number and characteristics of the households in each zone, a certain number of trips is generated. In the second step, trip distribution, trips are separated out into categories based on their origin and purpose: generally, these categories are home-based work, home-based other and non-home based. In each of three categories, trips are matched to origin and destination zones using the data that has been collected. In mode choice, trips are assigned to a mode (usually auto or transit) based on what’s available in a particular zone, the characteristics of the household within that zone and the cost of the mode for each mode in terms of money and time. Since most trips by bicycle or walking are generally shorter, they are assumed to have stayed within one zone and are not included in the analysis. Finally, in route assignment, trips are assigned to the network. As particular parts of the network are assigned trips, the vehicle speed slows down, so some trips are assigned to alternate routes in such a way that all trip times are equal. This is important because the ultimate goal is system-wide optimization, not optimization for any one individual. The finished product is traffic flows and speeds for each link in the network.[11]
Ideally, these models would include all the different behaviors that are associated with transportation, including the complex policy questions that are more qualitative in nature. Obviously, because of the nature of transportation this can’t be the case. The result is models that may estimate future traffic conditions well, but are ultimately based on assumptions made on the part of the planner. Some MPOs do some additional submodeling on things like automobile ownership, time of travel, location of land development, location and firms and location of households to help fill in these holes, but regardless what is created are models, and models always include some level of uncertainty.[11]
The postanalysis phase involves plan evaluation, program implementation and monitoring of the results. Johnston notes that for evaluation to be meaningful it should be as comprehensive as possible. For example, rather than just looking at decreases in congestion, MPOs should consider economic, equity and environmental issues.[11]
A large part of planning for transportation involves the technical four-step process that is designed to predict where future investments need to be made. It’s important to understand the public involvement implications of this. The discussion above was just a brief overview of the process, so it’s difficult for members of the public to delve into the issues and confront the models that planners use. This a cause for concern especially as study by Flyvbjerg, Skamris Holm and Buhl (2005) found that many of the models that planners use to sell big-ticket highway and rail projects are fundamentally flawed and often grossly inaccurate.[12]
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