Stockholm Congestion Charging Research Articles

Efficiency vs equity: Conflicting objectives of congestion charges

This paper analyses the trade-off between equity and efficiency in the design of the Stockholm congestion charging systems. Comparing different designs for Stockholm, the paper shows that the most efficient system is the least equitable. Indeed, we show that moving towards a more efficient system design favours high-income-users most. The reason is the uneven distribution of workplaces and residential areas, combined with richer socio-economic groups living in areas with more workplaces. Hence, the conflict between efficiency and equity of this policy arises from the spatial mismatch of residential areas and locations of employment, and the spatial separation between low-income and high-income groups that characterise most cities. This paper shows that these spatial patterns have a large effect on the distribution effects of the congestion charges and that the system design can have a major impact on equity.

Stockholm congestion charging: an assessment with METROPOLIS and SILVESTER

ABSTRACTThis paper reviews and compares the performance of two dynamic transportation models – METROPOLIS and SILVESTER – which are used to predict the impacts of congestion charging for Stockholm. Both are mesoscopic dynamic models treating accumulation and dissipation of traffic queues, route choice, modal split and departure time choice. The models are calibrated independently for the baseline situation without charges and applied to forecast the effects of congestion charging. The results obtained from the two models are mutually compared and validated against the actual outcome of the Stockholm congestion charging scheme. Both models successfully predict the outcomes of the congestion charging trial at both aggregate and disaggregate levels. Results of welfare analysis, however, differ substantially due to differences in model specification.

The Role of Decision Support in the Implementation of “Sustainable Transport” Plans

Improved decision support is deemed essential for the planning and implementation of sustainable transport solutions, but limited evidence exists that decision-relevant information is effectively used for these purposes. This paper applies a framework inspired by research in “knowledge utilization” to examine to what extent various kinds of decision support are used and have become influential in three different planning situations—a local cycle plan in Copenhagen, the Stockholm congestion charging trial and the UK national transport strategy. The results reveal the extensive use of decision support but also the difficulty of unpicking its exact role in each case. Stockholm presented the most successful case, with a mix of academic and experience-based knowledge inputs facilitating understanding and acceptance. The cycle plan example revealed very limited influence of cycling design guidance. The UK national transport strategy fell somewhere in between with evidence of assessment and monitoring of the plans being well bedded in the culture of the organizations involved, but less supportive of sustainability objectives. While decision support and monitoring are clearly relevant, they provide no guarantee for the implementation of sustainable transport solutions.

Revisiting the cost of the Stockholm congestion charging system

In January 2006, a system for congestion charging was introduced in the city of Stockholm, Sweden. The charging scheme was run in the form of a full-scale trial for seven months, after which it was deactivated, awaiting its evaluation and an advisory public referendum. Several parties, including representatives of the scientific community as well as media and special interest groups, have analysed and evaluated the system. A recurring theme in several of these analyses is that the cost to build and operate the system was excessive, compared to costs for other road charging installations. This study revisits some of the key project participants and archive data, to provide a deeper understanding of what were the major cost drivers and whether lower cost can be achieved in future installations. The approach taken is to emphasise understanding of the particular circumstances rather than comparing aggregates with other seemingly similar systems. The main conclusions include the identification of a rational actor paying an insurance against unacceptable risk, the importance of the election cycle, and the interplay between risk, acceptance, performance, and cost. A conceptual model for this interaction is suggested.

Reliability of congestion measures: Stockholm's case

The Stockholm congestion charging trial was implemented with the aim of satisfying a number of transport policy objectives related to reducing car use in the central area of Stockholm. However, the multifaceted nature of congestion that the charges aimed to alleviate was not technically defined. The traffic impact evaluation efforts were based on survey results for chosen links without any scientific review of the dynamic character of congestion or any investigation of the statistical characteristics of the chosen congestion indicator. Neither was there any analysis of area networks nor any calculation of an overall indicator. Based on a literature review, approaches for defining congestion and a number of alternative congestion performance measures were selected. Data from the trial ‘before' and ‘after' surveys were used to estimate congestion levels and the accuracy of the performance measures. Specific issues and lessons regarding the quality of the data collection are discussed. Accuracy rankings are presented for different cases, concluding that some performance measures showed better reliability in all situations whereas others proved to always be less reliable. These findings are used as a basis for recommendations regarding the implementations of the congestion indicators studied.

A cost–benefit analysis of the Stockholm congestion charging system

This paper presents a cost–benefit analysis of the Stockholm congestion charging system, based on the observed rather than on the model-forecasted data. The most important data sources are travel time and traffic flow measurements made in the year before the charges were introduced (during April 2005) and during the first spring with the charges (during April 2006, 4 months after the charges were introduced). Using matrix calibration, effects on the non-observed link flows and travel times are extrapolated, enabling us to calculate the social value of changes in travel times and travel costs. Impacts on traffic safety and emissions are calculated using standard Swedish CBA relationships. The system is shown to yield a significant social surplus, well enough to cover both investment and operating costs, provided that it is kept for a reasonable lifetime: investment and startup costs are “recovered” in terms of social benefits in around 4 years.

Framing the role of Decision Support in the case of Stockholm Congestion Charging Trial

Congestion charging was – as a trial – introduced in Stockholm from January 3rd to July 31st 2006. After the referendum in September 2006, the charging system was finally introduced as permanent from August 2007 with some adjustments to the Trial design. The idea of congestion charging is unique in a Swedish context, and the introduction of the Stockholm system has been highly controversial. Considerable efforts have therefore been undertaken to provide information that could serve as ‘Decision Support’ along the way. This has included e.g. modelling and forecasts before the Trial, a comprehensive evaluation programme during the Trial, extensive stakeholder consultations throughout, and various information and communication strategies. But what difference did this information input make, and what was its role in the process from initiating the system, to its final adoption? In this paper we pave the way for investigating the use and role of ‘Decision Support’ in the Stockholm Congestion Charging experiment. We adopt a definition of Decision Support as the systematic application of externally produced knowledge in transport planning and policy making processes. We then derive an analytical framework from the research literature on ‘knowledge utilization’ in policy making. This research has generally found that both ‘technical’, ‘communicative’, and ‘institutional’ aspects of the Decision Support matter for its influence on actual policy making processes and results. In our analysis we find a similar pattern. This high technical quality of the monitoring and evaluation programmes provided for solid verified results, while the institutional arrangements and the communication strategies helped to ensure the credibility and legitimacy of the information for the decision makers. The availability of rich contents coupled with strategies for the timely and targeted information delivery suggest that direct ‘instrumental’ use could have taken place. At a more general level the Trial represents an advanced form of ‘Decision Support’ that goes beyond the mere application of calculated results to encompass a process where the decision parameters themselves become part of the change process.

The Stockholm congestion – charging trial 2006: Overview of effects

The Stockholm congestion charging trial in 2006 demonstrated the effects of a full-scale time-differentiated urban road toll scheme. Improvements in travel times were large enough to be perceived by the general public. This was pivotal to the radical change of public attitudes that occurred during the trial and that resulted in a positive outcome of a subsequent referendum on a proposal for making the system permanent. This paper summarises the effects of the trial and analyses to what extent targets were met. Effects on congestion reduction were larger than anticipated, which also resulted in favourable economic and environmental effects. The trial showed that a single-cordon toll could affect traffic within a large area, i.e., not just close to the zone limits.

Lessons from the Stockholm congestion charging trial

The Stockholm congestion charging trial in 2006 resulted in large effects on traffic volumes and congestion. During the trial, public opinion gradually changed from a large majority opposed to the charges to a small majority in favour of them, and a referendum resulted in the charges being reintroduced in 2007. This paper summarises effects on traffic, travel times, travel patterns etc., and discusses what lessons can be learnt from the trial and the development after the reintroduction of the charges.

Building legitimacy for risky policies: The cost of avoiding conflict in Stockholm

The controversial nature of urban congestion charging policies makes them politically risky. Urban planners, policy makers and politicians are forced to consider how they can legitimately introduce a policy that the public may not want. Implementation in London, and failure in Edinburgh, raise questions about whether they should seek full citizen support, or work strategically towards implementation in the face of public opposition.This paper reports on an investigation of the Stockholm congestion charging trial (SCCT). It analyses the strategy developed by the city authorities to create legitimacy for the implementation of the SCCT. The SCCT is examined in two steps, firstly how the ‘trial+referendum’ approach was successful in securing public acceptance, and secondly how key aspects of the design of the trial and the subsequent referendum were adjusted in response to emerging risks, demonstrating the pragmatic approach of the city leaders managing the policy process. The study suggests that the city leaders chose a clearly pragmatic approach, grounded in compromise, yet subtly designed to avoid openly confronting the status quo. The strategy was continuously adapted and adjusted, in the face of emerging risks, and clearly served to create consensus while avoiding difficult questions of urban mobility.