We have a new website, and this page has moved!

You will be redirected to the new website in 5 seconds, or click here.
Please update your bookmarks.

  Methods for Urban Traffic Reduction


Finding solutions for problems that require drastic change require new ways of thinking and working. Urban tranportation is a field onto its own and many engineers and scholars are investigating its possibilities with great results. However there are a great many fields that interact with the patterns and problems of

  transportation that hardly make use of this, and for which there are very few tools to start thinking in new ways about tranportation systems, not least of all Urban Planning, Community Design and Architecture. During a seminar with the Yale School of Forestry & Environmental Design it surfaced that ready to use methods to structurally think about traffic problems hardly exist and are not used in practice. A method for structuring thought around this issue was then developed, and is presented here in short. This article only discusses a few ways of organizing thought for

development, and in no way aims to be complete. Instead it offers methods and tools that hope to inspire new ways of thinking that may eventually lead to other more comprehensive frameworks and methods for particular problems, or spark innovative solutions for complex transport problems.

Tom Bosschaert, MSc, MArch


p.1: Intro & Categorical Approach
p.2: Diagrammatic Approach
p.3: Application of Methods


Transportation uses one third of the energy of the western world, and reducing its footprint is one of the major areas of interest in urban design. Energy reduction is one of the largest potential gains in energy, and one of the most cost effective ways to engage rising energy costs, pollution problems and congestion. In this context this results in a focus on the reduction of energy usage through a diminution of motorized transport and an encouragement of non motorized ways of moving about. This article is about analyzing the problem of inner city traffic reduction, a set of frameworks to organize development in this area and the exploration of tools to achieve this, resulting from a study of various cities including Stockholm, Delft, Copenhagen and Antwerp.

How do we address the problem of inner city transportation in a coherent and communicable manner? How do we split up tasks to different agencies and how do we define a frame work within which we can work to tackle these tightly intertwined and complex issues?

One method of looking at it is to investigate the core need of transportation, and just focus on that. For this purpose transportation is a problem that can be captured in a single sentence or diagram: an individual's need or desire to go from one geographical point to the other. To organize our thinking regarding inner city transportation we need to find a framework to do so. I offer two ways of thinking about this, one by categorical type (method 1) and one by diagram (method 2). Both offer ways to develop plans for traffic reduction and give insight into the various components of travel.

The analysis of a tranportation system or an urban plan regarding thse matters is not complete just looking at these two methods. The choices involved in moving about are different for each individual, and psychological factors come into play, as well as more qualitative issues concerning status, comfort and safety. These should be investigated separately. The methods offered here deal with the reduction fo traffic in a permanent, sustainable manner, on large scales within the city.

Method 1: Categorical approach  
The categorical approach offers a simple categorization of travel types organized by their necessity (required/desired) and their dependence (destination/mode). Using these categories allows one to discuss and communicate clearly about different types of travel and apply different methods for each. These mostly apply to people transportation, but a similar categorization could be made for cargo. The categories are listed next, and explained below:
  • RM - Required travel by mode: Emergency vehicles, Remote locations
    • Undesirable to be reduced in current urban contexts

  • RD - Required travel by destination: work, administrative, goods
    • 1 - Apply Alternative Destination
      • 2 - Change Mode of Transport

  • DD - Desired travel by destination: leisure, family, sport
    • 1 - Remove Desire
      • 2 - Apply Alternative Destination
        • 3- Change Mode of Transport

  • DM - Desire travel by mode: road trip, cruising, etc
    • 1 - Remove Desire
      • 2 - Apply Alternative Destination
        • 3 - Capture Externalized Costs

RM , required transportation by mode. These journeys consist of travel for which no viable alternative exists. Required means there is no choice involved in the journey, as opposed to travel by desire. Examples are emergency services, goods deliveries, land surveyors etc. Perhaps in time things like the postal service could be entirely replaced by electronic media, but it is unlikely that the transportation of goods and emergency services will be replaced by non-motorized individual transport soon. Thus, this is a category which is usually unwise to restrict. This poses certain interesting challenges for the pedestrianized city areas since they will always, at any time, require access by these RM types of travel, since it is the mode, not the destination or origin, that defines its nature. Attention to these types of travel are highly important for urban planning contexts where pedestrianization is a large component. One can accommodate for some RM travel by, for instance, providing dedicated ambulance and fire engine routes.

RD, required transportation by destination, are journeys that are required but for which the mode is not predefined. Travel such as work and school commute, gathering required goods for living, and administrative tasks fall into this category. The majority of travel takes place in this category, and it should be the focus of intervention. The profiles of the different types of RD travel change per country, as for instance New Zealand’s education travel is almost non existent but makes up a significant amount of the total travel in Great Britain (fig 1 & 2). RD type travel can be reduced significantly in the first order by applying an alternative destination or point of origin. This could mean work at home for commuting, moving closer to work, using a local school, setting up online administration centers instead of physical offices, and so on. Secondary, this type of travel can almost always be converted in mode. One can take public transportation in many cases for this type of travel instead of the car. Where the first, alternative destination, can be hard to execute, it is something we as a society can work towards, and in the meantime we can execute efforts to implement the second intervention. The diagrammatic method offers more possibilities to deal with this category.

DD travel is a desire travel, one which is not necessary for normal life, and is therefore mostly irregular in nature. Think vacations, visiting friends, any voluntary travel to reach a certain destination. It is not so that this type of travel should be discouraged. Visiting friends, going to the park or other leisurely travel is vital to a vibrant city life and should be accommodated for as much as possible. Nonetheless, some type of DD travel could be discouraged in favor of others. Flying to remote corners of the world each year for recreational purposes is problematic from an energy stand point, for instance, and could easily be replaced by more modest travel needs. Also, one could provide for more decentralized services such as more, smaller education and sports facilities instead of just a few large ones to reduce travel times an thus allow for more flexible mode switching. Of course for DD the switching of mode is also the easiest to accomplish and those kinds of interventions can be readily implemented.

DM, desired travel by mode, is a more problematic kind. It's a voluntary type of travel chosen for its mode, notfor its destination. Think road trip. It’s a small contender in this framework but one which has roots that affect RD and DD as well. The main problem with DM when the mode is the car is that it is the car itself which provides the reason for travel, often there not being a destination. It is something present and thoroughly embedded in many western cultures, from cruising down the strip to transcontinental car explorations. It is very difficult to provide a replacement for these kind of travel, since the personal space a car offers, the feeling of freedom and the cultural associations that have sprung up around the car, mainly in the United States, are hard to overcome. Still, one should consider that less that one century ago culture and humanity was very able to do without the car, and it should not be hard to envision that the future does not necessarily include personalized motorized transport either. Ways of reducing DM type of travel is by providing quality alternatives, such as sufficient parks so one can be alone in a beautiful environment, and discouraging the use of the car as a form of entertainment, such as for instance with economical incentives (congestion charging), protecting natural areas by only allowing residents with passes, such as happens in the Netherlands, and so on.

fig 1. 1998-1999 New Zealand Ministry of Transport survey

fig 2. National Travel Survey, 1999-2001, Department for Transport; Road Casualties Great Britain 2002, Department for Transport

DM: Desire travel by Mode

Go to the next page to read about Method 2: the Diagrammatic approach >>


all contents of this website are © 2008 except