The Geography of Transport Systems
Jean-Paul Rodrigue (2017), New York: Routledge, 440 pages.
ISBN 978-1138669574
Transport Planning
Author: Dr. Brian Slack
1. The Traditional Transport Planning Process
"Long-range plans engender the dangerous belief that the future is under control." Max Gunther.
Transport planning focuses upon the public provision and financing of transportation assets, particularly roads and public transit systems. It usually addresses specific problems or broad transport concerns at a local level and has been traditionally a preoccupation of lower tier governments. Because of this fact, transport planning is most developed in the urban sphere, and it is there where most experience has been gathered. The planning process, however, has a number of similarities with the policy process. Identifying a problem, seeking options and implementing the chosen strategy are essential steps in planning too. Because it tends to deal with localized problems, the solutions adopted in transport planning tend to be much more exact and specific than policy directives.
The common perspective is that planning is the realm of the public sector, although the private sector owns and operate substantial transportation assets. For a long time, planning was a field dominated by traffic engineers who gave it a distinctly mechanistic character, in which the planning process was seen as a series of rigorous steps undertaken to measure likely impacts and to propose engineering solutions. There were four major steps; trip generation, trip distribution, modal split, and route selection. They involved the use of mathematical models, including regression analysis, entropy-maximizing models, and critical path analysis.
There are many reasons why the results of these models should be treated with caution:
  • They are only as good as the data they manipulate and many times the data is inaccurate or incomplete.
  • They are based on assumptions that the mathematical relationships between variables remain constant.
  • They can be manipulated to produce the outcome that would be the most preferred by the actors promoting a policy or a project.
  • Because the predictions were rarely subjected to subsequent evaluation, their validity is largely questioned, and the modeler is happy to predict the future since projections rarely question the validity of the methodology.
The predictions of future traffic flows produced by the four stage sequence are then used to identify planning options. Since the most common prediction of the modeling is that present capacities will be unable to cope with traffic growth, the tendency has been to produce planning solutions that call for an expansion of capacity. This has been referred to as predict and accommodate. It is the solution that has typified so much urban transport planning from the 1940s to the 1980s. It has given rise to the enormous expansion of highway construction that reinforces the dominance of the automobile. Rarely are there post mortems of the prediction models, and as has been learned by empirical observation, the issue of induced demand has distorted the actual traffic.
2. Contemporary Transport Planning
In cities traffic problems have increased significantly since the 1970s, despite a great deal of urban transport planning. There is a growing realization that perhaps planning has failed and that the wrong questions have been asked. Rather than estimate traffic increases and then provide capacity to meet the expected growth, it is now accepted that what is required is better management of the transport system, particularly maintenance, through new approaches to planning. Just as urban planning requires the inputs of many specialists, transport planning is beginning to utilize multi-disciplinary teams in order to broaden the scope of the planning process. Planning is still a multi-step process, but it has changed considerably:
  • Goals and objectives. While the goal of traditional transport policy, improving accessibility, is still useful, it has to be considered in the context of other desirable goals. For instance, improving safety and health, reducing emissions from vehicles, improving equity, enhancing economic opportunities, improving community livability, promoting mobility are all valid. But the prioritization of goals results in a very different planning process. Defining goals becomes a much more complicated stage in contemporary planning. Increasingly, goals have turned to consider managing demand, rather than trying to build capacity.
  • Options. Given the possible range of goals that transport planners have to consider, it becomes necessary to provide a set of possible options. Several objectives may be desirable, and thus it is important to consider what they imply. Several scenarios may have to be considered, and they must become important components of the planning process.
  • Identification of actors, institutions, stakeholders. Given that transport planning has the potential to influence so many elements of society, it is important that those affected by the transport problem and its potential resolution should be identified so that they can be engaged. This would be a much wider list of affected parties than simply those involved in transportation activity itself, and requires recognizing a role for citizen participation. Failure to do so runs the risk of a project to meet significant opposition from stakeholders perceiving that they have been left out or that can be negatively impacted.
  • Predicting outcomes, identifying benefits, and assessing costs. The stage of predicting the outcomes for each of the options is a critical step in the process. Models continue to play an important role, but whereas the traditional models were based on the number of trips, increasingly modeling is becoming more activity based. Transport is seen in the context of scheduling household decisions in time and space. Demographic and social data are used extensively, and mathematical models have become more sophisticated. Nevertheless, there are roles for other types of analyses, including non-objective forecasts. The predicted outcomes must then be assessed as to their benefits and costs. These may be expressed in monetary terms, but many transport planning situations call for measurement in other terms, such as visual impacts, environmental dislocations, and employment impacts.
  • Choosing course of action. Evaluation of the scenarios has to consider the costs and benefits from the frequently conflicting perspectives of the stakeholders and actors. Extensive public consultation may be required. The information has to be disseminated and explained so that an informed public can participate in the debate. Ultimately it will be the politicians who decide, but they are swayed by the strength of the arguments presented by the transport professionals, and in publicly contentious cases by pressure brought to bear by citizen groups.
Planning is commonly scale specific and multidimensional.
3. Transport Demand Management
In rejecting the former paradigm of building capacity, transport planners have turned increasingly to managing both demand and the transport system. Building roads has produced a car-oriented society in which the other modal alternatives have little opportunity to co-exist. Car ownership is beyond the ability of the transport planner to control directly and the question remains if it should. But car use and ownership is affected by land use and density, both elements that planners can affect. High population densities, in particular, favor walking, bicycling and public transit use. It is for this reason that a great deal of attention in planning is being paid to densification and integration. This includes concentrating development along well served transport corridors (transit oriented development) and increasing densities in areas undergoing rehabilitation.
Managing the demand for transport is made up of a large number of small interventions that cumulatively can impact of car use, but in particular improve the livability of cities. A sample of well-practiced and successful interventions includes:
  • Park and ride. Parking spaces are provided, usually close to an expressway, where drivers can board busses that provide service to the city center. This has become a staple feature in the outer zones of many US and British cities. Its success is variable, however, and there is some evidence from the UK that park and ride may actually increase car use, as people who may have used regular bus services now use their cars to drive to the car parks.
  • Traffic calming. Measures that seek to reduce the speed of vehicles in urban areas, such as speed bumps and street narrowing. For residential streets the goal is to make their use by car drivers unattractive because of the obstacles, for thoroughfares the objective is to reduce the average speeds. The measures indicate the need for much greater attention to street design and layout.
  • Priority lanes for busses and high occupancy vehicles. Lanes on major thoroughfares and expressways that are reserved for busses, taxis and passenger vehicles with several occupants. This has become an important feature of transport planning in North America, where major highway expansion projects offer priority lanes. The goal is to encourage use of busses and high occupancy vehicles that can be seen to travel at higher speeds along the reserved lanes by other drivers who may be stuck in traffic jams.
  • Alternate work schedules. Encouraging work hours other than the dominant 9 to 5 schedule. One of the great problems in transport planning is that demand is concentrated in two main peak periods. In the past, efforts were made to meet this demand by increasing road capacity, which was never sufficient, and resulted in an under use of the capacity the other 20 hours each day. Promoting flexible schedules and encouraging telecommuting are policies that are seeking to spread out the demand for transport over more hours and even reducing the demand altogether.
  • Promoting bicycle use. In some countries, particularly the Netherlands, the bicycle is an important mode of travel. It is a green and healthy mode, but in automobile dependent cities, the bicycle does not share the roads easily with trucks and cars. Encouraging greater use of the bicycle requires significant planning adjustments, such as the provision of bicycle lanes and bike stands.
  • Car sharing. Encouraging drivers to share car use with neighbors or co-workers. Information technologies have enable to extend car sharing schemes to a wider base.
  • Enhancing pedestrian areas. In most cities vehicles dominate the streets. In many areas of high population density, the quality of life (enhanced safety, less pollution etc.) and the visual attractiveness of streetscapes can be enhanced by excluding vehicles from streets altogether, or limiting access to public transport vehicles. In Europe this has become a distinctive feature of the historic cores of many cities.
  • Improving public transit. For fifty years or more public transit use as declined in most cities. Yet it is the only major alternative to the car in these cities, and thus enhancing the use of transit has become a major planning objective. Improvements include making transit more attractive, by improving bus schedules and improving the appearance and comfort of transit vehicles and stations. At the same time efforts are underway to widen the range of transit alternatives. These include extending commuter rail services, and constructing new systems such as light and heavy rail modes.
  • Parking management. Restricting on-street parking and charging higher rates for parking. This also applies to the parking of delivery vehicles.
4. Pricing
While planning interventions may have a positive cumulative effect in shaping transport demand, some economists suggest that a more direct approach involving imposing more stringent cost measures on car users is necessary. It is widely accepted that car users pay only a small proportion of the actual costs of their vehicle use. Economists argue that the external costs should be borne by the users. As intuitively rational as this argument may be, there are several problems with its application:
  • First, there are difficulties in measuring externalities, with considerable variations in estimates between different studies. Different types of use, speeds, engines, vehicle weight, or driving conditions, make it difficult to produce broadly accepted values. Decision makers have difficulty in agreeing to impose charges when there is a diversity of evidence about external costs.
  • Second, there are practical difficulties in collecting these costs. One of the easiest and most widely used methods is a gasoline tax. It is a crude approach, however, because it imperfectly distinguishes between driving conditions and engine type. A fuel efficient vehicle may have just as high consumption in heavy urban traffic as a less efficient vehicle in a rural setting.
  • Third, is the political difficulty of imposing such additional costs on the public. In North America in particular, free access to roads is regarded as a right, and it is intensely unpopular to propose any new forms of revenue generation that hints at additional taxation.
The effectiveness of economic controls is evident by the experience of Hong Kong, where, despite high incomes, car ownership and use remains at a very low level. This is due in the main to the high cost of parking. An even more drastic example is Singapore, where extreme measures limiting car purchases, high vehicle licenses, electronic tolls on highways, and cordon pricing in the downtown area have restrained car use.
The use of pricing mechanisms may be less in other countries, but the trend towards greater application of some forms of tolling is accelerating. Cordon pricing has been applied in a number of jurisdictions where access to certain areas, usually the CBD, is tolled. The most famous application was the decision to charge private vehicles for entry into Central London in early 2003, a program that has proved to be successful, despite a great deal of opposition.
Another form of charging is the imposition of tolls on new highways and bridges. In North America, the public had become used to the notion that highways are free of access, a legacy of the Interstate Highways Act, funded largely by Congress. In both Canada and the US legislation now permits private companies to build and operate private roads and bridges, and to collect tolls to cover costs. In Canada, Highway 407 outside Toronto and the Confederation Bridge linking Prince Edward Island to the mainland are examples of tolled facilities developed and operated by private corporations. The same trend applies to developing countries such as China where many new roads and bridges are toll based.
Another form of pricing is congestion or "fair" pricing. Here certain lanes of a highway are tolled, but at variable rates. When traffic is moving freely, the charges for the tolled lanes are nil. But as traffic builds up and speeds are reduced, the costs of using the reserved lanes increase. Collection of the tolls is electronic, and drivers are informed of the current charges by large signs. Drivers are given a choice therefore, to stay in the slower lanes for free, or move to the tolled lanes at a cost that is proportionate to the speed on the congested lanes. This system is now in place in several US States, after successful tests in California and Texas.
5. Intelligent Vehicles and Intelligent Highways
Technology is seen by many transport planners as a solution to a wide range of transport problems. This is an approach that has achieved wide acceptance in the US, where there has always been a strong emphasis on seeking engineering solutions to urban transport problems. It involves using information technologies (ITS) to provide better information and control over traffic flow and individual vehicle use. Many of the solutions involve the application of remote sensing techniques along with ITS.
One of the most promising approaches involves Interactive Highways. They are a means of communication between the road and driver that warn of approaching road conditions. Warnings include electronic message boards that suggest alternate routes to approaching motorists, designated radio frequencies that give updated traffic reports. It is based on a closed-circuit TV system (CCTV) that records lane-by-lane occupancy, volume and speed. At the same time ramp meters record in real time the amount of traffic entering the highway. This information is analyzed and processed at a control center that can dispatch emergency equipment to accidents as they happen, and can inform other drivers of road conditions, accidents, construction and delays.
A further technology is Emergency Signal Priority. This is a means of providing emergency vehicles and public transport busses priority at traffic lights in congested areas. The system allows a vehicle equipped with a system emitter to send a coded infrared message to the system detector, installed at the traffic intersection. When activated, the detector receives the coded message and then either holds the existing green light until the vehicle passes through or changes the existing red light to a green light.
ITS is being applied in many further innovative ways to improve the efficiency of emergency vehicles. For example, in Montreal mathematical models are being used to predict where road accidents are likely to occur given the time of day, traffic volumes and weather conditions. Ambulances can be assigned to these zones. Once deployed and assigned to a specific event, optimal routing is determined and relayed to drivers. When the first responders have identified the extent and type of injuries, the information is relayed to a control center which determines availability of doctors and nurses at which hospital emergency room, and suggests a routing for the ambulance using a least-time model estimation.
ITS is providing many solutions to the problems of road pricing. Toll collection is increasingly using electronic means to collect tolls without requiring vehicles to stop at toll booths. In its simplest form, vehicles equipped with a transponder that emits details of the vehicle are allowed to pass through toll lanes without stopping to pay. Receptors at the booth record the passage and debit the account. This is at the heart of the cordon pricing and of most new toll systems in place.
This technology, however, is being wedded to global positioning systems (GPS), which is likely to produce radical changes in the way vehicular traffic is priced. This combination of technologies will permit a more effective means of applying road pricing than the road tax. Vehicles will be required to have an on-board unit that includes a GPS receiver, a set of digital maps showing jurisdictional boundaries, an odometer feed, a set of distance rate charges, and a wireless communication system to report billing data. During each trip the GPS determines the jurisdictional zones, the odometer calculates the distance traveled in each zone, and the computer tabulates the running total of fees, and periodically signals the data to the billing agency. These systems are presently being evaluated in several states in the US. A comparable system is already in place in Germany, where since late 2004 all truck movements are charged an environmental tax based on distance traveled and vehicle characteristics.
6. Freight Planning
The vast preponderance of transport planning, certainly at the urban level, has been devoted to passengers. The automobile and public transit issues have pre-occupied planners since individual mobility can be a highly political issue (drivers are also voters). Yet, freight traffic represents a significant part of many problems that planning seeks to address. The models and data inputs used in transportation planning are of little relevance when applied to freight movements. For example, demographic data, such as household size, the backbone of passenger analysis, are irrelevant for freight. The bi-polar daily peak of traffic movements applies only to passengers, freight movements being distributed in a different profile over a 24 hour period.
While trucks account for approximately 10% of vehicles on the road, their size, low maneuverability, noisiness, and high pollution output make their presence particularly objectionable. Truck pick-up and delivery in city centers is particularly problematic because of limited parking. At the same time trucks are vital to the economy since they provide critical supplies. Commerce is dominated by trucking, and the logistics industry in particular is dependent on road transport for pick up and delivery. Garbage pick up, snow removal, and fire protection are among many essential services that are truck oriented.
Planning for freight movements, such as city logistics, is still in its infancy. As a largely private sector activity it is difficult to control, and many of the decisions that affect trucking are made by the industry itself. The emergence of large distribution centers on the outer fringes of metropolitan areas is taking place without much public control or oversight. In Europe, some attempts to manage such development by establishing publicly-promoted freight villages had only limited success.
Several cities are seeking to limit trucking as pressures keep mounting up. In many jurisdictions limits on heavy trucks in urban areas are in place, and there are restrictions on the times of delivery and pickup, which in some European cities extend to the exclusion of all trucks in the urban core during daytime hours. The question remains about to what extent constraining urban freight circulation impairs the economy.
All these steps are the beginning of the emergence of a more comprehensive freight planning process. In many cities there is limited data on freight traffic, so that planning takes place on an ad hoc basis. A much greater focus on freight planning is required, since freight distribution is an important component of urban mobility and activities.