CONTRAM > Advanced features

ITS modelling in CONTRAM has been developed over many years by TRL and, most recently, with the support of the Swedish National Road Administration which is using it in the development of driver information systems in Stockholm and other large cities. In the UK, CONTRAM is being used in the real time control system of the motorway network in Kent.

A standard assignment run represents an 'average' day. However, in the event of an incident, for example an accident that reduces network capacity for a period of time, drivers' behaviour may change in response to information by Variable Message Signs or unexpected queues on their intended route.

Scenarios can be easily set up using CONTRAM's graphical user interface. Incidents, VMS signs and diversion routes may be defined and displayed on screen.

CONTRAM allows simple junctions to be coded in seconds, while complicated ones can be coded to a high level of detail and accuracy.

The time-dependent queuing relationships used are consistent with those in the TRL junction design programs ARCADY (roundabouts), PICADY (priority intersections) and OSCADY (signals).

• multiple plans
• part time signals
• optimised cycle time
• optimised stage lengths
• opposed turns
• approach flares
• phase delays

A successful assignment model needs an accurate trip matrix. Matrix estimation is a technique for modifying a trip matrix so that, when assigned to a network, the modelled link flows are a closer match to observed link counts. Typically it is used to update an old trip matrix using a recent set of traffic counts.

Time-dependency is at the heart of the way CONTRAM works so of course there is a facility to define counts by time slice or combinations of time slices. Weights can be applied to counts, reflecting that some counts may be less accurate or more variable than others.

Formulae built into CONTRAM provide detailed statistics on fuel consumption and emissions. These use results of European research as the basis for the calculations. Default pollutants include CO, HC, CO2, NOx and particulates.

Cost benefit appraisal of new infrastructure or traffic control measures may be undertaken using TUBA with which CONTRAM interfaces.