CHAPTER1. INTRODUCTION
tested.
The traffic light controllers of Carlos Gershenson have decision variables which
influence the performance of these controllers. Simulations are very useful for op-
timizing decision variables of a system, when it is evaluated on its performance
[OK02].
Simulations are done for many purposes and a common approach consists of
formulating the problem, analyzing, modeling and experimenting. In this way
simulation results can be obtained successfully [Bal98].
New traffic light controllers can be checked in different scenarios on a realistic
traffic simulator. The simulation model has to be as realistic as possible to obtain
convincing results. Testing traffic light controllers in the real world would not
only be expensive in time and money, but it could also disturb the traffic flow or
even cause physical damage to vehicles and drivers.
Some have used probabilistic cellular automata for simulating traffic [FSS04b,
FSS04a].
Drivers, traffic light controllers and others make their own decisions which
results in an emergent behaviour. Agent technology can be used for construct-
ing detailed behaviours for individual entities. It is possible to run simulations
on multiple computers for a given road map. When the map is divided into
smaller pieces, one for each computer, the computational performance will in-
crease [KEW]. Also others have used agent technology for simulating traffic
[Sot, DS04, Nag04, WS02]
A description of an agent-based traffic simulator by Levi and WenthWorth [KEW]:
The main entities in the traffic network are road segments, inter-
sections, vehicles, traffic lights, signs and sensors, which are mod-
eled as agents. The traffic network can be partitioned into regions,
along geographical boundaries. Agents corresponding to entities in
the same region are hosted together in the same agent community, so
that they have a high-bandwidth, low latency communication among
them. Vehicle agents are mobile: as they enter a new region, they will
physically migrate to the agent community hosting that region.