Editing driving behavior parameters autonomous driving

For the simulation of autonomously driving vehicles, in particular for those electronically coupled as part of a convoy (platooning), you can define attributes for driving behavior that differ from the attributes of human driving behavior.

When dealing with platoons and vehicles in platoons, Vissim accounts for specific properties and behavior (Platoon properties and properties of platooning vehicles).

Note: The simulation of platooning in Vissim is suitable for evaluating the effects of platooning as a whole on the network. However, it is not suitable for obtaining specific data on vehicles within the platoon, for example to calculate emissions of vehicles driving in the platoon.

Examples of simulation of typical traffic situations

Vehicles form a platoon on a lane of a defined section of a highway and continue their journey within the platoon. The platoon dissolves downstream of the link section.
A vehicle drives up to the platoon and becomes part of it.
The platoon's lead vehicle drives up to a vehicle and the vehicle becomes part of the platoon.
A vehicle leaves the platoon by taking a highway exit to follow its route or path.

Using simulation results

Evaluating the simulation results of platooning can help answer the following questions, for example:

To what extent does platooning change the standstill times on highway approaches?
How does it impact the number of vehicles within the platoon?
To what extent does platooning change the capacity on a link section?

Tip: You can find examples of autonomous vehicles in the directory ..\Examples Training\Autonomous Vehicles (AV).

Example video: Platooning in your simulation

Vehicles approach preceding vehicles and form a platoon. Vissim visualizes this with the help of the graphic parameter DrawingMode > Use color scheme > Index in platoon of Vehicles In Network:

Select attributes for the driving behavior autonomous driving

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 Autonomous Driving tab.

5. Enter the desired data.

Element	Description
Maintain absolute braking distance	EnforcAbsBrakDist: For braking, the vehicle accounts for the distance necessary to stop without causing a collision should the vehicle in front it stop immediately without a braking distance. The absolute braking distance applies to vehicles in the following cases: Following behavior: The desired safety distance corresponds to at least the absolute braking distance. Lane change: When deciding to change the lane, the vehicle takes into account the absolute braking distance to both the new vehicle preceding it and to the new vehicle following it. If the absolute braking distance is not sufficient, the vehicle does not change the lane. For following behavior and lane changes the following applies: If for the vehicle the car following model Wiedemann 74 is selected, the standstill distance ax is added to calculate the absolute braking distance for other vehicles. If the car following model Wiedemann 99 is selected, instead the standstill distance CC0 is added. In a crossing conflict, the vehicle travels the conflict area in the subordinate flow, if the vehicle in the main flow can maintain the absolute braking distance. Vehicle inputs: The vehicle is inserted into the Vissim network with at least the absolute braking distance. Conflict areas:The absolute braking distance applies to vehicles that are involved in the conflict and have priority: The vehicle is inserted into the Vissim network with at least the absolute braking distance. The gap time the vehicle with the right of way needs to come to a stop before the conflict, is calculated by Vissim from the current speed of the vehicle and the maximum deceleration possible at this speed. The time it takes the other vehicle to cover a distance of 1 m, driving at its current speed, is added to the gap time. The absolute braking distance is not effective where priority rules are used.
Use implicit stochastics	UseImplicStoch: If this option is selected, Vissimuses a variable stochastic value for the following attributes and for the estimation uncertainty, which takes into account variations in human perception. This variable stochastic value is based on a) the time distribution CC1 (for the speed-dependent part of the desired safety distance) and b) on internal distributions that apply to the desired acceleration and deceleration: Safety distance Desired Acceleration Desired Deceleration Minimum lateral distance If the option is deselected, Vissim uses non-variable deterministic values that are based on the meridian of the time distribution CC1 (for the speed-dependent part of the desired safety distance) and of internal distributions that apply to the desired acceleration and deceleration.
Platooning section
Platooning possible	PlatoonPoss: Activates platooning, vehicles can drive within the platoon
Max. number of vehicles	Maximum number of platoon vehicles (MaxNumPlatoonVeh): Maximum number of vehicles allowed to drive in the platoon. This includes vehicles that want to leave the platoon. Default 7
Max. desired speed	Maximum platooning desired speed (MaxPlatoonDesSpeed): Maximum speed at which all vehicles in the platoon can drive, default value 80.00 km/h. The lead vehicle and the following vehicles use the Maximum platooning desired speed, even if it differs from the desired speed. The desired speed is the default speed for each vehicle when driving outside of the platoon. In a reduced speed area, the maximum platooning desired speed is no higher than the speed of the reduced speed area.
Max. distance for catching up to a platoon:	Maximum platoon approach distance (MaxPlatoonApprDist): Maximum distance [m] to the last vehicle of a platoon up to which a vehicle tries to join the platoon. Default 250.00 m.
Gap time	Platooning - follow-up gap time (PlatoonFollowUpGapTm): Follow up gap time between a vehicle and its preceding vehicle within the platoon (Desired speed and safety distance within the platoon). Default 0.60 s
Minimum clearance:	Platooning - minimum clearance (PlatoonMinClear): Minimum clearance [m] of vehicle to preceding vehicle within the platoon (Desired speed and safety distance within the platoon). Default 2.00 m

For a vehicle within the platoon, you can display its driving state, interaction state, and its position within the platoon (index in platoon) during simulation in the Vehicles in network list (Displaying vehicles in the network in a list).

Superordinate topic:

Defining driving behavior parameter sets