Modelling study

A visual DONALD representation of multiple car agents moving along a road agent will be created. An ‘emergency vehicle’ agent will also be designed and visually represented to which the car agents will respond. The road and vehicles will be displayed in a Scout Window. Scout windows will also be created to house buttons to make the environment interactive, allowing users to start and stop the clock, and introduce an emergency vehicle into the road system.

The road agent will be defined in terms of its width and length, with left and right edges. More than one lane of traffic may be introduced. The length of the road will not be considered relevant to the aim of this model and so will be defined as repetitive, i.e. with cars travelling beyond the end of the road appearing again at the beginning. However the visually represented road will by necessity have a length, so that the location of vehicles can be defined in terms of their horizontal and vertical position on the road. As the model progresses the road may allow some traffic to flow in both directions if this is thought beneficial to aid the modelling study, and time permitting.

Car agents will have observables such as their location with respect to other cars and their speed. Their dependencies will include their position on the road, the observables of other cars (for example the speed of a car may depend on the speed of the vehicle in front, and its distance ahead), and the observables of emergency vehicles.

An ‘emergency vehicle’ agent will be designed which will have observables to which the car agents will respond. This vehicle will be sent on to the road by the user or perhaps instead at a set time. It will inherit the observables of other cars and may inherit similar dependencies to them. It will also have several different states (set by the user) to which cars will respond differently. These states might include: no emergency warning, flashing lights on, siren on, flashing lights and siren on.