1. 4th International Conference on High Performance Scientific Computing 4th International Conference on High Performance Scientific Computing A Framework for Rule-Based Traffic Simulation Using Cellular Automata V. H. Thanh, T. V. Hoai

2. 2 Outline Introduction Cellular Automata Framework Architecture Rule Implementation

3. 3 Introduction In the big cities, especial in Viet Nam, Traffic jam is continuously and intensively occurring –Traffic simulation can be of great help Traffic simulation models can roughly be divided into macroscopic and microscopic –Macroscopic models examine the dependencies between traffic flow, traffic volume, and average velocities –Microscopic models investigate the movements of individual vehicles Cellular automata (CA) models belong to the group of microscopic models

4. 4 Cellular Automata In 1948, Johann Louis von Neumann introduced concepts of cellular automata (CA) Ingredients of a cellular automaton –The universe on which the CA is computed A discrete lattice of cells –The cells’ states –The cells’ neighbors –A local transition rules

5. 5 Traffic Cellular Automata TCA models are also called particle- hopping models

6. 6 Vehicle Movement Vehicle movement is defined by a rule set –Single lane moving –Lane changing behavior –Driver behavior The rules are consecutively applied to all vehicles –The usual way to update the cells in a lattice is parallel (synchronous, simultaneous) –In some cases also other updating methods are used (e.g. random sequential)

7. 7 Framework Architecture Vehicle Data CA Engine Monitor Physical rules Law / Regulations Signal Control Scheme Conflict Resolve Transition Rules …

8. 8 Rule Implementation Using declarative language, for example prolog –Easy to describe the rule –Easy to use implement This approach is appropriate with the rule can be described in if … then … form

9. 9 Example I: Unsignalized Intersection Each road has 500 cells x 8 lanes View Clip

10. 10 Example II: Signalized Intersection Each road has 500 cells x 8 lanes Pre-Timed Signal Scheme View Clip

11. 11 Thanks for your listening!