Eighty-five percent of all journeys in the EU are made on the road network. Demand has more than doubled over the last 25 years, and further growth is expected. This will lead to greater congestion, with huge economic and environmental costs. Therefore, calls are increasingly heard for the introduction of policies and targets for traffic reduction. For this, policy-makers need to know what measures are most effective, based on the limited experience to date.
DANTE aimed to evaluate the effectiveness of measures that can reduce the amount of travel, including:
- mode switching (from cars);
- time switching (from peak periods);
- destination switching (to closer places);
- trip substitution and avoidance.
The purpose was to inform policy-makers on good practice.
The project has produced guidance for selecting and implementing strategies to reduce the need for travel, particularly aimed at car use in cities. Some 30 measures were assessed on case study evidence gathered in different European cities. The results are summarised in the DANTE Best Practice Guide, aimed at urban decision-makers. The information is presented in a structured way, leaving the user the freedom to choose between different options.
The main finding is that travel reduction is most likely where several policy measures work together. For example, restraint on car use has proved successful when combined with promotion of alternative modes of transport, while pure reduction measures seem to have been relatively unsuccessful. The scale of reduction is often difficult to quantify, which will make policies difficult to justify. Also, it has been seen that restraint in one area of a city can lead to increased use of cars elsewhere (e.g. outside the city centre), unless policies are well co-ordinated.
Resource barriers (whether financial, human or physical) have been the most common problems, particularly for alternative modes. These have hindered implementation in almost 20% of the cases studied. Restrictions on car travel more commonly meet social barriers. Land-use planning measures aimed at traffic reduction generally seem to encounter serious barriers.
The project concluded that push measures are essential – the perceived advantages of car use are so great that there will only be a minimal transfer from car driving, while car use remains unrestricted.
The most effective strategies for traffic reduction seem to involve the promotion of alternative modes. It remains to be seen whether trip substitution/avoidance and time/destination switching hold greater potential in the future, starting from a baseline of limited experience and success, or whether further investment in mode switching is the most cost-effective approach.
Public awareness messages are needed to encourage a change in travel behaviour, as well as providing information on the available alternatives. Authorities themselves, as employers, are in a good position to lead by example. This can be done through parking policies, provision of bicycle facilities and the use of teleworking methods.
It is important to co-ordinate policies (e.g. within a local transport plan) to reinforce the objective of traffic reduction. For example, measures to promote the efficiency of the traffic system need to consider the travel-encouraging consequences, and the creation of out-of-town centres (which encourage longer, car-based trips) requires careful control.