t TNO Inro Chania, 14 March 2002Paul van Koningsbruggen & Rick van der Arend 1 Distributed Control from policy statements to local traffic control Presentation at the OMNI-workshop

t Chania, 14 March 2002Towards a Concept for Distributed Control2 Content The Idea behind Traffic Management in The Netherlands Linking Network Policy and Local Practice A concept for Distributed Control

t Chania, 14 March 2002Towards a Concept for Distributed Control3 The objective is a common traffic management approach Elst Arnhem A12 A15 A12 A50 A348 N325 N225 N224 N785 N348 Urban Road Inter-urban Road Motorway River Velp Trajectory speed 60 km/h Less traffic in the city Regional traffic only Less traffic regarding construction works

t Chania, 14 March 2002Towards a Concept for Distributed Control4 Three Optima for Traffic Management Network OptimumUser Optimum Policy Optimum Social & Economical Context Utilisation of the InfrastructureIndividual Preferences Road Users Traffic Management Strategy

t Chania, 14 March 2002Towards a Concept for Distributed Control5 When the infrastructure capacity is insufficient to meet traffic demand ……. Today’s reality: choices have to be made in the allocation of the scarcity in infrastructure capacity Traffic Management Strategy Three Main Research Questions: How can we balance the three optima and translate them into operational goals for traffic control systems? How can we balance the optimum on a network level and the local, situational optimum? How can we get the traffic control strategy to focus on the actual traffic flows Positioning services (measures) Guide operations

t Chania, 14 March 2002Towards a Concept for Distributed Control6 The Idea is to link Network Policy and Local Practice Network  Traffic Management Strategy ‘What we aim at’ Balancing the three optima in a control strategy Traffic Management Tactics Balancing the operation of traffic control systems ‘What we gain’ Local Goals & Best Practices Practice Policy

t Chania, 14 March 2002Towards a Concept for Distributed Control7 The Blueprint for the Traffic Management Concept Momentary Network Policy: priorities and quality levels Operational Traffic Control a.o. Traffic Management Tactics Traffic Traffic State Monitoring Data & Local, situational restrictions Momentary ‘Reference Scheme’ Signals = ‘translation’ TNTN TLTL

t Chania, 14 March 2002Towards a Concept for Distributed Control8 Network Policy: assigning priorities and defining quality levels to strive for

t Chania, 14 March 2002Towards a Concept for Distributed Control9 Two possibilities for the Traffic Management Tactics Traffic Management Tactics: IF …A… THEN …B… Option 1: A = State of the Network B = set of traffic management measures Direct activation of the traffic management measures Option 2: A = State of the Network B = Set of priorities and Quality Levels Autonomous activation of the traffic management measures, within the context of (B)  Distributed Control

t Chania, 14 March 2002Towards a Concept for Distributed Control10 Linking Network Policy and Local Practice by using ‘Gerdien’ Tower Model Network Trajectory Segment Link Point Intersection Trajectory Node Segment Node Link Node Priorities & Quality Levels (Situational) Constraints

t Chania, 14 March 2002Towards a Concept for Distributed Control11 The Quintessence of the proposed ‘Distributed Control’ Approach Plausible Approach Proposed Approach RM 1RM 2RM n Ramp Metering Management System TL 1TL 2TL n Traffic Light Management System VMS 1VMS 2VMS n VMS Management System Traffic Manager DN1DN2DNn Partial Networks T1T2Tn Trajectories S1S2Sn Segments L1L2Ln Links Traffic Manager

t Chania, 14 March 2002Towards a Concept for Distributed Control12 The idea is to co-ordinate local goals within the context of the network policy Three (or more?) paradigms: Industrialisation hierarchical order; command and control structure from network level to link level Arbitration: conflicts on lower level will be referred to arbitration on a higher (network) level Utilitarianism negotiation on lower level, while adhering to a mutual, higher network goal Distributed Control based on the Multi-Agent Principles

t Chania, 14 March 2002Towards a Concept for Distributed Control13 DECISION EVALUATIONOBSERVATION ACTION 'TRAFFIC' Cycle of Information Processing in the Kernel of an Agent

t Chania, 14 March 2002Towards a Concept for Distributed Control14 Link-Agent 2 Link 1 Service-Agent Constraints Link 2 Link-Agent 1 Traffic Data Impact on Link 1 Impact on Link 2 Local, Network Goal Two Type of Logical Agents: infrastructure Agents and Service Agents

t Zuidpolder, 4 Maart 2002 Agents in Verkeersbeheersing15 Link Agents observe en evaluate the local traffic situation and decide the required improvements in terms of ‘basic controls’ (e.g. I - V - C) and ask the relevant Service Agents for these improvements. In case the local services are not sufficient anymore, the Link Agents start to negotiate, to gain the improvements together. Operation of the Link Agents

t Zuidpolder, 4 Maart 2002 Agents in Verkeersbeheersing16 Service Agents observe and evaluate incoming claims of Link Agents within their sphere of influence. Then, the Service Agents decide how to activate the actuators (traffic management systems) in order to meet with as many claims as possible. On a network level, the Service Agents negotiate, in order to co-ordinate the actuators. Operation of the Service Agents

t Chania, 14 March 2002Towards a Concept for Distributed Control17 Link Claims Activating Actuators Distributed Controller Infrastructure Network Communication Resulting in a Concept for Distributed Control

t Zuidpolder, 4 Maart 2002 Agents in Verkeersbeheersing18 State of Research: implementation of the distributed concept for a Motorway Stretch with Ramp Metering Scenario 1: no ramp metering Scenario 2: individual ramp metering (‘Alinea’ algorithm) Scenario 3: distributed control, node as sphere of influence Scenario 4: distributed control, complete motorway stretch as sphere of influence

t Chania, 14 March 2002Towards a Concept for Distributed Control19 Resume The Idea behind Traffic Management in The Netherlands Linking Network Policy and Local Practice A concept for Distributed Control

t Chania, 14 March 2002Towards a Concept for Distributed Control20 Thank you for your attention !