Editing the driving behavior parameter Signal Control

For the driving behavior at signal controls, specify the following:

  • how vehicles respond to amber signal
  • how vehicles respond to red-amber signal
  • a reduced safety distance before stop lines
  • a time distribution for the response time

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

The list of defined network objects for the network object type opens.

The list shows driving behavior parameter sets. 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 Signal Control tab.

5.  Make the desired changes:

In the section Reaction after end of green:

Element Description
Amber behavior

Defines the behavior of vehicles when they approach an amber light.

  • Continuous check: Driver of vehicle continuously decides whether to continue driving or whether to stop. Vehicles assume that the amber light will only be visible for another two seconds. They then decide continuously, with each time step, whether they will continue to drive or stop.
  • A vehicle will not brake, if its maximum deceleration does not allow it to stop at the stop line, or if it would have to brake for longer than 4.6 m/s².
  • The vehicle will brake, if at its current speed, it cannot drive past the signal head within two seconds.
  • Both braking and stopping are possible for cases that lie in between these two scenarios. Using a normally distributed random variable, Vissim decides whether or not the driver will brake.
  • One decision: The decision made is maintained until the vehicle crosses the stop line. To calculate the probability p, i.e. whether a driver stops at an amber light or not, the program uses a logistic regression function, with the following probability factors: Alpha, Beta1, Beta2, vehicle speed v (m/s) and distance to stop line dx (m):

 

Probability factors

Only active if One decision is selected. The default values of the Probability factors Alpha, Beta 1, Beta 2 are based on empirical data:

  • Alpha: default 1.59
  • Beta 1: default -0.26
  • Beta 2: default value 0.27
  • The decision made is maintained until the vehicle crosses the stop line.
  • To produce the most accurate results, select the One decision option. To do so, for the look ahead distance, change the attributes Number of interaction vehicles and Number of interaction objects (Editing the driving behavior parameter Following behavior). As signal heads (as well as some other network objects) are modeled internally as vehicles, they are only recognized if the number of vehicles or network objects between the vehicle in question and the signal head does not exceed the number specified in the attributes Number of interaction vehicles and Number of interaction objects minus 1.
  • When the One decision option is selected, higher values set for the probability factors increase the probability that a vehicle will stop at an amber light. This means that the higher these values are, the less likely the vehicle is to run an amber or a red light:
  • Alpha is greater than the default value 1.59
  • Beta 1 is greater than the default value -0.26 but less than 0.00.
  • Beta 2 is greater than the default value 0.27

In the section Reaction after end of red:

Element Description
Red-amber behavior

Modeling country-specific or regional behavior at red/amber signal.

  • Go (same as green)
  • Stop (same as red)
Reaction time distribution

Reaction time of a vehicle to the Go signal. It causes a time delay between the time step when the signal switches to Go and the time step when the first vehicle upstream of the corresponding stop line starts to move. The Go signal is defined by the Behavior at red/amber signal attribute:

  • Stop (same as red): The Go signal is green. The response time is effective from the time step the signal changes to green.
  • Go (same as green): The Go signal is red-amber. The response time is effective from the time step the signal changes to red-amber.

If no time distribution is selected, the default time is 0 s.

In the section Reduced safety distance close to a stop line:

Element Description
 

The attributes define the behavior of the vehicles near the stop line.

Factor

If a vehicle is located in an area between Start upstream of stop line and End downstream of stop line, the factor is multiplied by the safety distance of the vehicle. Default value 0.6 The safety distance used is based on the car following model. The safety distance may be reduced via the Safety distance reduction factor attribute (Editing the driving behavior parameter Lane change behavior). For lane changes in front of a stop line, the two values calculated are compared. Vissim will use the shorter of the two distances.

Start upstream of stop line

Distance upstream from the signal head. Default 100 m

End downstream of the stop line

Distance downstream from the signal head. Default 100 m