Multi-objective road pricing: a cooperative and competitive bilevel optimization approach

Costs associated with traffic externalities such as congestion, air pollution, noise, safety, etcetera are becoming unbearable. The Braess paradox shows that combating congestion by adding infrastructure may not improve traffic conditions, and geographical and/or financial constraints may not allow infrastructure expansion. Road pricing presents an alternative to combat traffic externalities. The traditional way of road pricing, namely congestion charging, may create negative benefits for society. In this effect, we develop a flexible pricing scheme internalizing costs arising from all externalities. Using a game theoretical approach, we extend the single authority road pricing scheme to a pricing scheme with multiple authorities/regions (with likely contradicting objectives)

Modelling traffic hindrance caused by road construction as part of a multi-criteria assessment framework

One of the consequences of the increased utilization of road infrastructure is more frequent maintenance work. Since generally road works result in less available road capacity, we can witness an increase in traffic hindrance, which involves delays and externalities as noise, air quality, safety and the emission of GHG. Hindrance is generally not restricted to the location where the maintenance works take place, but can occur in a wider area as a result of altered flow patterns in the whole network. The type of reconstruction, and the way the work is executed determines not only the cost and service life but also the amount of hindrance. We present a multi-objective framework where for a longer period of time, cost and hindrance of specific road maintenance works can be determined, as part of a decision support tool for the optimal planning of maintenance works. For this we developed an alternative traffic assignment method that is able to predict traffic flow in a network in the presence of road works

Multi-objective optimization of multimodal transportation networks: Interpretation of the Pareto set from a case study in Amsterdam. (online)

We define the optimization of infrastructure planning in a multimodal network context as a multi-objective network design problem, rather than evaluating a pre-defined set of network scenarios. This provides insight into the extent to which facilitating better transfers between modes can contribute to various aspects of sustainability, namely accessibility, operation subsidies, use of urban space and climate impact. For a real life case study the Pareto set is estimated by a genetic algorithm, showing that minimizing the use of urban space clearly competes with minimizing operations subsidies. Furthermore, travel time and climate impact are rather in line with each other. Finally it is shown that the Pareto set is strongly influenced by the frequency of one specific train line, indicating that increasing line frequency more effective than opening new park and ride facilities or new train stations

Handling multiple objectives in optimization of externalities as objectives for dynamic traffic management.

Dynamic traffic management (DTM) is acknowledged in various policy documents as an important instrument to improve network performance. This network performance is not only a matter of accessibility, since the externalities of traffic are becoming more and more important objectives as well. Optimization of network performance using DTM measures is a specific example of a network design problem (NDP) and incorporation of externality objectives results in a multi objective network design problem (MO NDP)). Solving this problem resorts in a Pareto optimal set of solutions. A framework is presented with the non-dominated sorting algorithm (NSGAII), the Streamline dynamic traffic assignment model and several externality models, that is used to solve this MO NDP. With a numerical experiment it is shown that the Pareto optimal set provides important information for the decision making process, which would not have been available if the optimization problem was simplified by incorporation of a compensation principle in advance. However, in the end a solution has to be chosen as the best compromise. Since the Pareto optimal set can be difficult to comprehend, ranking it may be necessary to assist the decision makers. Cost benefit analysis which uses the economic compensation principle is a method that is often used for ranking the alternatives. This research shows, that travel time costs are by far the most dominant objective. Therefore other ranking methods should be considered. Differences between these methods are explained and it is illustrated that the outcomes and therefore the eventual decisions taken can be different

Raamwerk voor het inzichtelijk maken van verkeershinder bij wegonderhoud

Door een toenemende verkeersintensiteit op de Nederlandse wegen neemt de slijtage van de weg en daarmee de noodzaak tot het plegen van wegonderhoud toe. Tegelijkertijd wordt om dezelfde reden de tijd en ruimte om zonder verkeershinder werkzaamheden uit te voeren steeds minder. Dit is de reden dat het beperken van verkeershinder op dit moment een belangrijke rol speelt in de \ud uitvoering van wegwerkzaamheden. In deze paper wordt een raamwerk gepresenteerd waarmee het proces van wegonderhoud tot verkeershinder inzichtelijk wordt gemaakt. Aandacht wordt besteed aan wegbouwkundige aspecten zoals de kwaliteit van de verharding en de te nemen onderhoudsmaatregelen, de verkeerskundige effecten als gevolg van de genomen (verkeers)maatregelen en de resulterende \ud verkeershinder. Beslisvariabelen in het raamwerk komen overeen met de middelen en maatregelen die op dit moment ten dienste staan van wegbeheerders en opdrachtnemers. Tenslotte wordt kort ingegaan op de afweging van de gewenste kwaliteit van de verharding, de kosten van de te nemen maatregelen en de hoeveelheid verkeershinder.\u

Optimising Differentiated Tolls on Large Scale Networks, by using an Intellegent Search Algorithm

The design of an optimal road pricing scheme is not a trivial problem. Following the Dutch government’s kilometre charge plans, this paper focuses on the optimisation of link based toll levels differentiated in space and time. The optimal toll level design problem is formulated as a bi-level mathematical program. In the upper level we minimise an object function, e.g. the average travel time in the network, using a fixed number of price categories. At the lower level a dynamic traffic assignment model is used to determine the effects of differentiated road pricing schemes on the traffic system. Focus of the paper is on the upper-level where optimal toll levels are approximated. In the optimisation procedure different variants of a pattern search algorithm are tested in a case study. Inspection of the solution space shows that many local minima exist, so the selection of the initial solution becomes important. In the case study however it appears that in all local minima the value of the objective function is almost the same, indicating the fact that many different toll schemes result in the same average travel time. The case study is also used to test the performance of the different variants of the pattern search algorithm. It appears that it is beneficial to change more variables at a time and to use a memory to remember where improvement of the objective function has been made. First tests on a medium scale network showed that it is possible to apply the framework on this network, though further computational improvements are needed to apply the framework to large scale networks, for example by parallel processing