# Time-Dependent Matrix

Matrices are often calculated based on an average traffic situation. But, with the following options, it is possible to get more precise values:

• trafficMode
• startTime
• duration

The following usecase are handled, depending on the combination of these options:

• time-independent matrix ; distances and travel times are based on an average traffic situation
• point-in-time matrix ; distances and travel times are calculated based on a traffic situation for a certain date/time
• multiple travel time matrix ; travel time profiles are returned for a period of time, based on the known traffic situation

Limitations

• time-dependent matrix requires asynchronous calculation ; i.e. using the startMatrixCalculation operation
• all locations should be located within a rectangle of 500 kilometers maximum

## Time-independent matrix

• options[trafficModes] = AVERAGE
• options[startTime] is null
• options[duration] = 0

Time-independent matrices are calculated based on the average speed observed on a road, whatever the date.

The calculation is the fastest, and the synchonous operation calculateMatrix can be used.

## Point-in-Time matrix

• options[trafficMode] = REALISTIC or AVERAGE (options[startTime] should be defined)
• options[startTime] is defined or null (options[trafficMode] = REALISTIC means 'now')
• options[duration] = 0

Knowing a specific date, the distances and travel times are calculated using the known traffic situation for this date.

If options[trafficMode] is REALISTIC, then the current traffic situation is also taken into account to calculate the travel time of the routes.

## Multiple TravelTime matrix

• options[trafficMode] = REALISTIC or AVERAGE (options[startTime] should be defined)
• options[startTime] is defined or null (options[trafficMode] = REALISTIC means 'now')
• options[duration] > 0

The options[startTime] and options[duration] define the horizon of the matrix calculation.

The response of this calculation contains the distances (if requested) and the travel time profile. This profile defines the different travel times for the same route, during the whole horizon. This could be useful to get the trend of the travel time on a specific route.

If options[trafficMode] is REALISTIC, then the current traffic situation is also taken into account to calculate the travel time of the routes.

Please note that for Multiple TravelTime matrices, only the encoded response can be requested. The client has to decode the response. The needed information are available in the Results Representation concept page. See also the Time-Dependent Matrix tutorial.

Try it in the Travel Time Profiles code sample.