Neïla Bhouri

Managing Highways for Better Reliability: Assessing Reliability Benefits of Ramp Metering

Despite the importance of reliability, few countries monitor it or explicitly incorporate it into transport policy making. Nevertheless, a number of policy options are available to improve this aspect of transport management. Active management of the network through ramp metering is recognized as an efficient way to control motorway traffic and improve average travel time. Far less is said about the reliability benefits of ramp metering. This paper assesses reliability benefits of ramp metering on the basis of a before-and-after study on the A6W, a French motorway near Paris. Several indicators for travel time variability are applied before and after the introduction of ramp metering. For purposes of taking reliability into account in policy impact evaluation, cost–benefit assessment provides a consistent framework within which to assess the monetized benefits. The monetary value of the reliability benefits of ramp metering is therefore calculated, and the policy implications of the results are discussed. The results suggest that in addition to providing gains in average travel time, ramp metering significantly improves reliability of travel times. It is also proposed that indices such as buffer time or planning time are useful for communicating the results, both for network operators and for users. Failing to unbundle the time-savings benefits of a project between average travel time and the variability in travel time is likely to lead to suboptimal policy solutions. Managing existing capacity better can be a cost-effective way to improve both average travel time and the variability in travel time.

A multi-agent system to regulate urban traffic: Private vehicles and public transport

This paper proposes a strategy of urban bimodal traffic regulation based on multi-agent modelization. The objective of this strategy is to work on the duration of the traffic lights to regulate traffic for transport modes that include private and public transport vehicles, principally the bus. The model respects the method of bus regulation with a route agent, who supervises all the vehicles on the route while ensuring that they respect the regular time intervals between them. Bus priority is granted by reserving a green stage for buses as soon as they enter the route in question. This stage is prioritised for those buses running late, and whose priority does not lead to deterioration in the regularity of the time intervals between them and the preceding vehicle; an interval they must respect at bus stops. Regulation is obtained thanks to communication, collaboration and negotiation between the agents; the programming is developed under the JADE (Java Agent Development Framework) platform.

Towards Urban Traffic Regulation Using a Multi-Agent System

This paper proposes a bimodal urban traffic control strategy based on a multi-agent model. We call bimodal traffic a traffic which takes into account private vehicles and public transport vehicles such as buses. The objective of this research is to improve global traffic and reduce the time spent by buses in traffic jams so that buses cope with their schedule. Reducing bus delays is done by studying time length of traffic lights and giving priority to buses, more precisely to buses running late. Regulation is obtained thanks to communication, collaboration and negotiation between the agents of the system. The implementation was done using the JADE platform. We tested our strategy on a small network of six junctions. The first results of the simulation are presented. They show that our MAS control strategy improves both bus traffic and private vehicle traffic, decreases bus delays and improves its regularity compared to a classical strategy called fixed-time control.

Collaborative Agents for Modeling Traffic Regulation Systems

The development of surface public transportation networks is a major issue in terms of ecology, economy and society. Their quality in term of punctuality and passengers services(regularity between buses) should be improved. To do so, cities often use regulation systems at junctions that grant priority to buses. However, most of them hardly take into account both public transport vehicles such as buses and private vehicle traffic. This paper proposes a bimodal urban traffic control strategy based on a multi-agent model. The objective is to improve global traffic, to reduce bus delays and to improve bus regularity in congested areas of the network. In our approach, traffic regulation is obtained thanks to communication, collaboration and negotiation between heterogeneous agents. We tested our strategy on a complex network of nine junctions. The results of the simulation are presented.

Automated negotiation for traffic regulation

Urban congestion is a major problem in our society for quality of life and for productivity. The increasing communication abilities of vehicles and recent advances in artificial intelligence allow new solutions to be considered for traffic regulation, based on real-time information and distributed cooperative decision-making models. The paper presents a mechanism allowing a distributed regulation of the right-of-way of the vehicles at an intersection. The decision-making relies on an automatic negotiation between vehicles equipped with communication devices, taking into account the travel context and the constraints of each vehicle. During this negotiation, the vehicles exchange arguments, in order to take into account various types of information, on individual and network scales. Our mechanism deals with the continuous aspect of the traffic flow and performs a real-time regulation.

Public Transport Priority for Multimodal Urban Traffic Control

Abstract In order to improve the travel time of surface public transport vehicles (bus, tramway, etc.), several cities use Urban Traffic Control (UTC) systems enabling to give priority to public transport. This paper reviews these systems. Further on after a debate on their insufficiencies in the global regulation of the urban traffic on a whole network, the paper proposes intermodal regulation strategies, operating on intersection traffic lights to regulate the traffic, favouring the public transport. All these strategies are based on the Linear Quadratic (LQ) optimal control theory, but they are different in their ways of taking into account the public transport in the optimization problem. The simulation tests are carried out in a network of eight intersections and two public transport lines.

Constraint-Based Negotiation Model for Traffic Regulation

The increasing communication abilities of vehicles and recent advances in artificial intelligence allow new solutions to be considered for traffic regulation, based on real-time information and distributed cooperative decision-making models. However, current techniques do not consider all the travel history and information of the vehicules. In this paper, we propose an automated negotiation mechanism with policies (along with specialized variants), which enables a distributed regulation of the right-of-way of the vehicles at an intersection, based on the travel context and the constraints of each vehicle. To account for the regulation needs, the technique employs a novel and generic negotiation model. Our simulations show that the proposed mechanism can increase the efficiency of the regulation.

Bimodal traffic regulation system: A multi-agent approach

The development of surface public transportation networks is a major issue in terms of ecology, economy and society. Their quality in terms of punctuality and passengers services (regularity between buses) should be improved in order to improve their attractiveness. To do so, cities often use regulation systems at intersections that grant priority to buses. The problem is that each transportation mode has its own characteristics and a dedicated decision support system. Therefore, most of them hardly take into account both public transport vehicles such as buses and private vehicle traffic. This paper proposes a multi-agent model that supports bimodal regulation and preserves monomodal regulation. The objective is to improve global traffic, to reduce bus delays and to improve bus regularity in congested areas of the network. In our approach, traffic regulation is obtained thanks to communication, collaboration and negotiation between heterogeneous agents. We tested our strategy on a complex network of nine junctions. The results of the simulation are presented.