Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Congestion Charging in Urban Networks: Modelling Issues and Simulated Effects
KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics. KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR.ORCID iD: 0000-0002-3738-9318
2011 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

One of the major challenges cities face today, in their development towards sustainable urban areas, is the need for an efficient and environmentally friendly transport system. This transport system should manage to tie together the city without strong adverse impact on urban environment, air-quality and climate change. The specialized labour (and leisure) market, typical of a large urban area, exaggerates the need for efficient travel, as it is increasingly difficult to live and work within short distances.   

The use of demand management tools has become more frequent in transport planning with this development towards more sustainable cities. Whereas investing in new capacity was previously the main response to increased demand for travel, there is a much broader range of policies in use today. One of these demand management tools is congestion charging. Singapore was first to implement congestion charging and during the last decade it was followed by London and Stockholm, with increasing support from the citizens as a consequence. Many other cities have performed feasibility studies for introduction of congestion charging. 

The development of transport models for prediction of demand management tools, such as congestion charging, has however not been able to keep up with this change in kind of policy. Transport models that were developed for prediction and evaluation of infrastructure investments, such as new motorways, are often used to forecast effects of policies aimed at managing demand, which too often results in poor prediction.

This thesis focuses on the needs for modelling of congestion charging. The state-of-practice models used before implementation in Singapore, London and Stockholm are reviewed, as well as more advanced dynamic models developed for prediction of congestion charging and other demand management tools. A number of gaps in the modelling of congestion charging are described and a new model called SILVESTER is developed, which closes some of these gaps. In particular, SILVESTER involves dynamic mesoscopic modelling of traffic flows, flexible departure times and users with heterogeneous preferences.

The thesis describes the implementation of SILVESTER and considers and compares different methods of demand aggregation in order to reduce run-time of the large-scale dynamic model (Paper I). It also describes how preferred departure times of road users can be determined in calibration such that consistency exists between the departure time choice model and dynamic traffic flows which are input to assignment (Paper II). The unique implementation of congestion charging in Stockholm gives the possibility to validate SILVESTER on real-world measurement of reductions in traffic flow and behavioural adjustments to the charges (Paper III). SILVESTER is then used to analyse several modified versions of the Stockholm congestion charging scheme and to compare welfare and equity effects of the different schemes. It is shown that the welfare of the current scheme could be improved if charges were allowed to differ by location and driving direction (Paper IV). It is shown that the benefits of congestion charges calculated using SILVESTER are greater than the benefits calculated with a static model. Finally, the reasons for the greater benefits are investigated (Paper V).

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology , 2011. , x, 59 p.
Series
Trita-TEC-PHD, ISSN 1653-4468 ; 11:003
Keyword [en]
Transport Modelling, Congestion Charging, Departure Time Choice, Dynamic Traffic Simulation, Welfare Effects, Equity
National Category
Transport Systems and Logistics
Identifiers
URN: urn:nbn:se:kth:diva-43732ISBN: 978-91-85539-79-6 (print)OAI: oai:DiVA.org:kth-43732DiVA: diva2:448786
Public defence
2011-11-09, F3, Lindstedsvägen 26, KTH, Stockholm, 10:30 (English)
Opponent
Supervisors
Funder
TrenOp, Transport Research Environment with Novel Perspectives
Note
QC 20111019Available from: 2011-10-19 Created: 2011-10-18 Last updated: 2012-06-12Bibliographically approved
List of papers
1. A Dynamic Transportation Model for the Stockholm Area: Implementation Issues Regarding Departure Time Choice and OD-pair Reduction
Open this publication in new window or tab >>A Dynamic Transportation Model for the Stockholm Area: Implementation Issues Regarding Departure Time Choice and OD-pair Reduction
2009 (English)In: Networks and Spatial Economics, ISSN 1566-113X, E-ISSN 1572-9427, Vol. 9, no 4, 551-573 p.Article in journal (Refereed) Published
Abstract [en]

Road traffic congestion is an increasing problem in urban areas. Building new roads often attracts latent demand and turns parts of the city into building sites for several years. Policy measures that stimulate more effective use of the existing network, such as variable road pricing, are therefore becoming increasingly popular among policy makers and citizens. These measures are often aimed at changing the temporal distribution of traffic. Yet transportation models taking departure time choice into account are rare. This paper describes the implementation of an urban transportation application for Stockholm, which includes departure time choice, mode choice and time dependent network assignment. Through iterations between demand and supply the objective of the transportation model is to forecast effects of congestion charges, intelligent transport systems and infrastructure investments on departure time choice. The complexity of large-scale departure time choice modelling and dynamic traffic assignment is high, which results in very long run times. Therefore, research on how to increase model efficiency is needed. This paper describes choices made in the implementation for a more efficient model.

Place, publisher, year, edition, pages
Springer, 2009
Keyword
Transportation model, Departure time choice, Mixed logit, Dynamic traffic simulation, Peak-spreading, Congestion charges
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:kth:diva-10512 (URN)10.1007/s11067-009-9104-0 (DOI)000273113200004 ()
Projects
silvester
Note
QC 20100823Available from: 2009-05-20 Created: 2009-05-20 Last updated: 2017-12-13Bibliographically approved
2. Estimating preferred departure times of road users in a real-life network
Open this publication in new window or tab >>Estimating preferred departure times of road users in a real-life network
2008 (English)In: Proceedings of the  European Transport Conference 2008, 2008Conference paper, Published paper (Refereed)
Abstract [en]

The demand for travel continues to increase in European cities of today, which results in long car travel times and highly congested road networks, especially during the morning and afternoon peak periods. The congested car system gives rise to high emissions of particles and greenhouse-gases, which is negative for both the local and global environment. Congestion also causes an uncertain travel time, something that in the latest years has been recognised as a major factor in car-users perception of trip disutility. Congestion is time-dependent in nature. Therefore, not only the spatial distribution of trips over the network is important in analysis and prediction, but also the temporal distribution of trips. A traditional congestion-relieving strategy such as a capacity expansion often has an impact on when people travel, since shorter travel times during the peak hour can attract traffic from the peak shoulders. The temporal effects are even more pronounced for the new policy measures gaining ground today, e.g. variable road pricing. Most variable road pricing systems aim at moving traffic from the peak hour to the peak shoulders, so called peak spreading. The means by which this is done is by charge differentiation: it is most expensive to travel at the most congested point in time. However, most large-scale transport planning models in use today are static and changes in the temporal distribution of trips are not considered. It is therefore likely that false conclusions are drawn when using these models to evaluate the ability of different pricing schemes or infrastructure investments to alleviate congestion.SILVESTER – A Dynamic Transport ModelTo better model the temporal distribution of traffic has been the basis in the development of SILVESTER (SImuLation of choice betWEen Sarting TimEs and Routes), which is a dynamic transport model for the Stockholm area. In SILVESTER road network conditions during the extended morning peak period (06:30-09:30) are modelled. The morning is divided into twelve 15-minute time intervals and a departure time choice model allocates trips to each interval depending on their attractiveness. The attractiveness of a time interval is determined by its corresponding travel time, travel time uncertainty, monetary cost and how close it is to the preferred time interval (PDT) of the traveller. The travellers can also choose to start before 06:30 or after 09:30. Mode choice is partially modelled by introducing the possibility for car-users to switch to public transport if it is perceived as a better option than any of the time intervals. It is distinguished between three trip purposes: business trips, trips with fixed schedule and school trips, and trips with flexible schedule and other trips. In SILVESTER iteration towards a general equilibrium between supply and demand is performed. The supply quantities (travel times, uncertainties etc.) are calculated with the mesoscopic dynamic traffic assignment model CONTRAM, whereas the demand for each time interval and public transport alternative is calculated with a mixed logit discrete choice model. A calibrated origin-destination-matrix (OD-matrix) for the Stockholm CONTRAM network exists and is based mainly on traffic counts but also on travel times for some selected OD-pairs. Calibration of Preferred Departure TimesEven though many trip-timing models use the concept of schedule delay, which is defined as the deviation from a preferred departure/arrival time, little work has been done on how to find the PDT-distribution when applying the model. For estimation the survey respondents can be asked to state their preferred time of travel, but for large-scale applications similar studies are expensive and time consuming. Previous work has often assumed a simplified distribution, such as all travellers in a market segment having the same PDT. Without calibration of PDT’s, e.g. using only a simplified exogenous assumption, the predictive capability of the transport model is questionable. Instead of making an exogenous assumption about the PDT-distribution this paper uses a reverse engineering approach to reveal PDT’s from the observed departure times of the reference situation. It is the combination of the estimated departure time choice model, the travel conditions and the observed departure times that can be used to get information about the PDT’s. Once the PDT’s have been calibrated for the reference situation they can be used in the evaluation of a congestion relieving strategy. This paper will present calibration methodology, obstacles overcome on the way and calibration results. It will also discuss future work in which the calibrated departure time choice model will be used to improve the design (charge levels and time periods) of a pricing scheme.

National Category
Civil Engineering
Identifiers
urn:nbn:se:kth:diva-10514 (URN)
Conference
European Transport Conference 2008, 6-8 October 2008, Leeuwenhorst Conference Centre/ The Netherlands
Projects
silvester
Note
QC 20101015.Tidigare titel: "Deriving Preferred Departure Times of Road-Users in a Real-Life Network".Available from: 2009-05-20 Created: 2009-05-20 Last updated: 2011-10-19Bibliographically approved
3. Impacts of time-varying cordon pricing: Validation and application of mesoscopic model for Stockholm
Open this publication in new window or tab >>Impacts of time-varying cordon pricing: Validation and application of mesoscopic model for Stockholm
2013 (English)In: Transport Policy, ISSN 0967-070X, E-ISSN 1879-310X, Vol. 28, no SI, 51-60 p.Article in journal (Refereed) Published
Abstract [en]

This paper uses a simulation model to compare traffic and welfare effects of changes to the charging schedule currently in use in Stockholm. In particular, a step toll is compared to its flat counterpart at two charging levels. The increments between steps are also increased in a peaked step toll scenario. Furthermore, results from simulation of the current toll ring are compared to real-world measurements in a first attempt to validate model predictions regarding impacts of a time-varying congestion charging scheme. In the model, car users have the possibility to respond to congestion charging by changing departure time, route or switch to public transport and travel times are calculated using mesoscopic traffic simulation. Validation shows that departure time choice adjustments because of congestion charging are overestimated by the model that is based on stated preference data. This warrants further research on discrepancies between stated and revealed adjustments to congestion charging. The current step toll reaches the highest social benefit estimate in model predictions, but differences in traffic effects between the current step toll and its flat counterpart are rather small. Furthermore, results show that demand changes occur in the model to a considerably greater extent for trips with low value of time. The differences in welfare effects is for that reason large for different trip purposes, indicating the importance of accounting for heterogeneous trips when modelling effects of congestion charges.

Place, publisher, year, edition, pages
Pergamon Press, 2013
Keyword
Congestion charging, Departure time choice, Time-varying charges, Schedule flexibility, Traffic simulation
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:kth:diva-43718 (URN)10.1016/j.tranpol.2011.06.006 (DOI)000321405400006 ()2-s2.0-84878636686 (Scopus ID)
Projects
Avenir
Funder
TrenOp, Transport Research Environment with Novel Perspectives
Note

QC 20130812

Available from: 2011-10-17 Created: 2011-10-17 Last updated: 2017-12-08Bibliographically approved
4. Alternative road pricing schemes and their equity effects: Results of simulations for Stockholm
Open this publication in new window or tab >>Alternative road pricing schemes and their equity effects: Results of simulations for Stockholm
2011 (English)In: Proceedings of the TRB 90th Annual Meeting, Washington, D.C., 2011Conference paper, Published paper (Refereed)
Abstract [en]

This paper uses a newly developed transport model to analyze effects of alternative road pricing schemes. The responses to road pricing included in the model are departure time, mode and route choice. Traffic analysis is performed on a large urban network of Stockholm using mesoscopic simulation. The compared pricing schemes differ in toll location and charged amount. Through calculation of consumer surplus per geographical zone, effects of the road pricing schemes are analyzed per income group and geographical area in order to study equity effects. Simulation results suggest that road pricing can be both regressive and progressive depending on the design of the pricing scheme, this even before the use of revenues to compensate users. Results also indicate that there can be a disagreement between which pricing scheme is preferable from a congestion mitigating point of view and which is preferable when looking at equity effects.

Place, publisher, year, edition, pages
Washington, D.C.: , 2011
Keyword
Road pricing, Traffic simulation, Equity effects, Departure time choice
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:kth:diva-43730 (URN)
Projects
Avenir
Funder
TrenOp, Transport Research Environment with Novel Perspectives
Note
QC 20111019Available from: 2011-10-18 Created: 2011-10-18 Last updated: 2011-11-21Bibliographically approved
5. Welfare effects of Stockholm congestion charges using dynamic network assignment
Open this publication in new window or tab >>Welfare effects of Stockholm congestion charges using dynamic network assignment
2011 (English)In: Proceedings of the European Transport Conference, Glasgow, UK, 2011Conference paper, Published paper (Refereed)
Abstract [en]

According to the standard textbook analysis, drivers as a group will be worse off with congestion charging if not compensated by revenues. This result is confirmed by an analysis of the Stockholm congestion charging scheme using a static model with homogenous users. However, both this static model and the standard textbook analysis omit three important factors: taste heterogeneity, effects of charges on the larger network arising from less blocking back of upstream links and behavioural adjustments in the temporal dimensions. Taking account of these factors, using a dynamic model with heterogeneous users in a large-scale network, we find that drivers as a group benefit directly from the charging scheme in Stockholm. This paper investigates the importance of the three factors omitted in the standard textbook and the static model analysis in the Stockholm case, finding that all three add significantly to the benefit of the charges.

Place, publisher, year, edition, pages
Glasgow, UK: , 2011
Keyword
Congestion charges, Congestion pricing, Road pricing, Acceptability, Evaluation, Urban transport policy, Mobility management, Transport externalities, Policy implementation
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:kth:diva-43731 (URN)
Conference
European Transport Conference
Funder
TrenOp, Transport Research Environment with Novel Perspectives
Note

QC 20111019

Available from: 2011-10-18 Created: 2011-10-18 Last updated: 2016-06-08Bibliographically approved

Open Access in DiVA

No full text

Authority records BETA

Kristoffersson, Ida

Search in DiVA

By author/editor
Kristoffersson, Ida
By organisation
Traffic and LogisticsCentre for Traffic Research, CTR
Transport Systems and Logistics

Search outside of DiVA

GoogleGoogle Scholar

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 899 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf