Editing the driving behavior parameter car following model

1.  On the Base Data menu, click > Driving Behaviors.

The Driving Behaviors list opens. Some driving behavior parameter sets can be predefined.

By default, you can edit the list (Using lists).

You can edit all driving behavior parameters for lane change, lateral behavior and following behavior in the list or in tabs with the following steps.

Note: In lists, you can use the  Attribute selection icon to show and hide attribute values (Selecting attributes and subattributes for columns of a list).

2.  Right-click the entry of your choice.

3.  On the shortcut menu, click Edit.

The Driving Behavior window opens.

4.  Select the Car following model tab.

5.  Enter the desired data.

Element Description

List box

Car following model for the car-following behavior. Depending on the selected car following model the Model parameters change.

  • No interaction: The vehicles do not recognize other vehicles. Platooning is not possible. Use this car following model as an easy way to model pedestrian flows with the vehicle types Man, Woman.
  • Wiedemann 74: The desired safety distance increases with the square root of the speed. At low speeds (with default values of the parameters: below 80 km/h) the desired safety distance is larger for Wiedemann 74 than for Wiedemann 99. This is why Wiedemann 74 is particularly suitable for inner-city and out-of-town weaving sections at low speeds. At higher speeds, the desired safety distance is smaller for Wiedemann 74 than for Wiedemann 99.
  • Wiedemann 99: The desired safety distance increases linearly with the speed. It is defined as a speed-independent time gap.

Model parameters

Displays different parameters depending on the car following model selected (Defining the Wiedemann 74 model parameters), (Defining the Wiedemann 99 model parameters). These model parameters also affect the saturation flow.

Defining following behavior based on the vehicle class of the preceding vehicle

You can base the model parameters for the vehicle following model on Wiedemann 74 and Wiedemann 99, depending on the vehicle class of the preceding vehicle. This can be done for every vehicle class defined. The following behavior takes effect from the moment the vehicle enters the vehicle input.

1.  To change the model parameters based on several vehicle classes, carry out the following steps in sequence for each desired vehicle class.

2.  Right-click the section Following based on vehicle class of preceding vehicle.

3.  On the shortcut menu, click Add.

A new row is inserted. The row contains the model parameters for the vehicle class with the lowest number. The latter is not displayed yet. All Wiedemann 74 and Wiedemann 99 model parameters that are relevant for the following behavior are displayed (Defining the Wiedemann 74 model parameters),(Defining the Wiedemann 99 model parameters). In the Increased acceleration column, you can define whether the vehicle falls back or accelerates when the preceding vehicle accelerates (Editing the driving behavior parameter Following behavior).

The model parameters of the vehicle following model that is not selected are marked as hatched, i.e. as not relevant.

4.  Into the boxes that are not hatched, enter the desired attribute values for the following behavior of the vehicle, if they differ from the default values.