The Propolis Approach to Urban Sustainability - Theory and Results From Seven European Case Cities
K Lautso, LT Consultants, FI
PROPOLIS is a research project within the Fifth Framework Programme of the EC. It belongs to the "Energy, Environment and Sustainable Development" Thematic Programme?s Key Action "City of Tomorrow and Cultural Heritage". DG Research and national organizations from Finland, Germany, UK, Belgium, Italy and Spain have funded it.
The objective of PROPOLIS was to research, develop and test integrated land use and transport policies, tools and comprehensive assessment methodologies in order to find sustainable long-term urban strategies and to demonstrate their effects in European cities.
A set of indicators was developed for measuring the environmental, social and economic dimensions of urban sustainability. Values for these indicators were calculated using advanced urban land use and transport models and new GIS and Internet based modules developed during the project. A decision support tool was used to evaluate the sets of indicator values in order to arrive at single aggregate environmental, social and economic indices describing the alternative policy options. To include the long-term land use effects, a time horizon of 20 years was used. In close contact with Client-Partners and international networks the system was used to systematically test and analyse policy options in 7 European cities using three different types of land use and transport models.
The main innovation of the project is the integrated and comprehensive but still transparent approach undertaken. Secondly, the approach applied has also produced innovative policy recommendations based on the system?s ability to forecast the indicator values into the future and to take into account the long-term land use effects.
The results show that, with growing traffic, the environmental sustainability deteriorates in all case cities compared with the current situation if no actions are taken. The trend is unlikely to change even if city specific reference scenarios, including local investment programmes, are adopted. Also, the social sustainability tends to deteriorate.
The aim of PROPOLIS was to find policies that could simultaneously improve all three dimensions of sustainability compared with the reference solution and, if possible, even improve the current level of sustainability. This goal was reached in most of the case cities using the same type of package approach combining pricing, investment and land use policies. This indicates that the approach could be transferable and similar strategies could work also in other European cities.
The local investment plans, normally consisting of an investment programme for both public transport and road investments, performed in the right direction but could not maintain the current level of sustainability. The various elements of the programmes were often found to encourage development towards opposing goals. Investment programmes should be designed to be consistent with the general goals set for the transport-land use system.
Different car pricing methods were able to produce positive results. However, their effects on land use have to be separately assessed as the balance of services and vitality of different areas may change too much.
Also public transport policies, increasing speed and service and reducing fares, worked well. However, also here special attention has to be paid to the land use effects and to their possible contribution to city sprawl. Although intended to decrease travel demand they could in the long-term lead to increases in private car use. Regulating car speeds had positive effects on traffic accidents, as intended, but the policy was not enough to compensate for the effects of the worsening opportunity, accessibility and air pollution related indicators. Thus, speed policies should be adopted on a case-by-case basis.
Different types of individual land use policies did not have significant positive effects on the overall sustainability indices. However, land use policies could successfully be used locally and to support the changes in demand caused by the car pricing and public transport policies.
Best results were achieved by using policy combinations, i.e. push and pull measures consisting of car pricing policies and simultaneous improvements of public transport through reduced fares and better speed and service. The combination produced cumulative positive results and the negative land use effects of the individual policies could be avoided.
Adopting the above policy packages lead to a 15-20% reduction in CO2 emissions, a 8-17% reduction in traffic accidents and often to at least small reductions in exposure to noise and pollutants and in the total time spent in traffic. In addition, the accessibility to the city centre and services was improved. The socio-economic benefits varied but were typically 1000 ? 3000 euro/inhabitant for the assessment period. Searching and defining more optimal local levels for the actions could further improve the results, as demonstrated in some case cities.
The PROPOLIS research has demonstrated that a complete urban policy programme should be evaluated both policy by policy and as a whole. A good urban policy programme consists of co-ordinated elements that work together to produce cumulative long-term effects that attain a balanced set of environmental, social and economic goals.
These elements may include:
* Combination of car and public transport pricing policies reflecting the external costs caused and with differentiation between peak and off-peak hours as well as congested and non-congested areas
* Targeted transport investment programmes meeting the changes in demand caused by the above policies and especially responding to the increased demand for better public transport speed and service
* A land use plan supporting the new need for people to live near central areas, in satellite cities or along well served public transport corridors, and the people?s increased need and opportunity to use public transport PROPOLIS has demonstrated that in typical European cities this type of strategy is likely to improve all dimensions of urban sustainability compared with the continuation of existing policies and, in best cases, increase the current level of sustainability ? improve our cities of tomorrow.
Association for European Transport