Impact of preconfigured traffic behavior
|
|
Note: You must have an automotive license. |
Preconfigured traffic behavior defines specific settings for driving behavior of surrounding traffic that take the selected driving style and the selected weather conditions into consideration. Your ego vehicles, which enter your Vissim network via the interface to an external driving simulator or by using a DriverModel.dll file, move within this surrounding traffic.
Applying the preconfigured traffic behavior affects your base data and attributes (Applying preconfigured traffic behaviors).
- Changed driving styles affect vehicle accelerations and decelerations, time gaps, and speeds for all road users in the Vissim network. The driving style can be adjusted from very comfort-oriented to very aggressive. You can adjust the preset speed of the vehicles proportionally.
- Changed weather conditions affect delays, time gaps, and speeds for all road users within the Vissim network. This leads to driving behavior that is adapted to the weather conditions, with realistic individual interactions between road users. However, it is not suitable for determining the capacity of traffic infrastructure. You can change the weather conditions to bad weather or very bad weather. You can also adjust the preset deceleration of the vehicles as well as the preset maximum speed proportionally.
Impact of selected traffic behavior on base data and attributes
The chosen traffic behavior affects accelerations, decelerations, gap times, and speeds of the surrounding traffic during a simulation run, influencing the driving behavior of all road users within the Vissim network. This results in realistic simulations of individual interactions between traffic participants, though it does not capture the overall behavior of all participants. Depending on the driving style you select, Vissim adjusts the following base data applied during the simulation runs.
Impact of selected driving style
Desired acceleration and deceleration
The values for vehicle types such as cars, HGVs, and buses are set by Vissim based on the selected driving style. The functions for desired acceleration and desired deceleration are set to values that correspond to those in the provided file defaults.inpx and are scaled by the following factors: 0.75; 0.875; 1.0; 1.25; 1.5. Maximum accelerations are set to match the desired accelerations. The maximum deceleration is set to-10m/s2 for aggressive driving styles.
Conflict areas
Vissim sets the following attribute values:
|
Attribute |
Very comfort oriented |
Comfort oriented |
Neutral |
Aggressive |
Very aggressive |
|
Front gap (default) |
0.75 |
0.6 |
0.5 (Vissim default value) |
0.4 |
0.35 |
|
Rear gap (default) |
0.75 |
0.6 |
0.5 (Vissim default value) |
0.4 |
0.35 |
|
Safety distance factor (default) |
1.95 |
1.7 |
1.5 (Vissim default value) |
1.2 |
1.05 |
Speed limitation in curves
If Speed limitation in curves is selected under Network Settings, Vissim adjusts the function values for vehicle types, such as cars, HGVs, and buses, based on the selected driving style. The functions for Speed limitation in curves are set to values matching those in the default file defaults.inpx, scaled by the following factors: 0´.8; 0.9; 1.0; 1.1; 1.2.
Driving Behaviors
Vissim sets the following attribute values for driving behavior with the car following model types Wiedemann 74 or Wiedemann 99:
|
Attribute |
Very comfort oriented |
Comfort oriented |
Neutral |
Aggressive |
Very aggressive |
|
Average standstill distance (w74ax) |
3 |
2.5 |
2 (Vissim default value) |
1.75 |
1.5 |
|
Additive part of safety distance (w74bxAdd) |
0.3 |
2.5 |
2 (Vissim default value) |
1.75 |
1.5 |
|
Multiplicative part of safety distance (w74bxMult) |
4.5 |
3.75 |
3 (Vissim default value) |
2.625 |
2.25 |
|
Wiedemann 99 – cc0 |
2.25 |
1.875 |
1.5 (Vissim default value) |
1.3125 |
1.125 |
|
Wiedemann 99 – cc1 |
Vissim generates new time distributions. These contain a descriptive suffix in their names. |
||||
|
Empirical Distribution |
Empirical Distribution |
normally distributed |
Empirical Distribution |
Empirical Distribution |
|
|
x = [0.0 0.9 1.8] Fx = [0.0 0.0 1.0] |
x = [0.0 0.9 1.4] Fx = [0.0 0.0 1.0] |
MV = 0.9 Std = 0.0(standard value Vissim) |
x = [0.0 0.75 1.0] Fx = [0.0 0.0 1.0] |
x = [0.0 0.5 1.0] Fx = [0.0 0.0 1.0]) |
|
Driving behavior parameters for driver errors
|
Attribute |
Lack of attention and driver errors (Driving style preconfigured - driver error) |
||
|
Attentive |
Inattentive |
Very inattentive |
|
|
Temporary lack of attention during following - probability |
0% |
2.5% |
5% |
|
Loss of attention during following - duration |
- |
0.5 s |
1 s |
|
Distraction - probability |
0% |
2.5% |
5% |
|
Distraction duration distribution |
Vissim generates new distributions These contain a descriptive suffix in their names. |
||
|
- |
normally distributed Mean 1.0; Default value 0.25 |
normally distributed Mean 1.0; Default value 0.25 |
|
|
Distraction lane angle distribution |
Vissim generates a new distribution. These contain a descriptive suffix in their names. |
||
|
- |
Empirical Distribution x = [0 0.005] Fx = [0.0 1.0] |
Empirical Distribution x = [0 0.010] Fx = [0.0 1.0] |
|
|
Lateral: Observe lateral behavior |
Not selected |
Selected |
Selected |
|
Speed misestimate distribution |
Vissim generates a new distribution. These contain a descriptive suffix in their names. |
||
|
- |
normally distributed Mean 1.0; Default value 0.025 |
normally distributed Mean 1.0; Default value 0.05 |
|
|
Conflict area are considered interaction objects |
Not selected |
Selected |
Selected |
Lane change behavior
|
Attribute |
Very comfort oriented |
Comfort oriented |
Neutral |
Aggressive |
Very aggressive |
|
Safety distance reduction factor: |
1.0 | 0.8 | 0.6 (Vissim default value) | 0.45 | 0.3 |
|
Lane change - duration |
5.0 s | 4.0 s | - | 2.5 s | 2.0 s |
|
Lane change: accepted deceleration - own |
-0.5 m/s2 |
-0.75 m/s2 |
-1 m/s2 (Vissim default value) |
-3 m/s2 |
-5 m/s2 |
|
Lane change: accepted deceleration - trailing vehicle |
-0.5 m/s2 |
-0.75 m/s2 |
-1 m/s2 (Vissim default value) |
-3 m/s2 |
-5 m/s2 |
|
Lane change: maximum deceleration - own |
-4 m/s2 |
-4 m/s2 |
-5 m/s2 (Vissim default value) |
-4.5 m/s2 |
-5 m/s2 |
|
Lane change: maximum deceleration - trailing vehicle |
-3 m/s2 |
-3 m/s^2 |
-3 m/s2 (Vissim default value) |
-4.5 m/s^2 |
-5 m/s^2 |
|
Lane change: To slower lane if collision time is at least |
11 s (Vissim default value) |
11 s (Vissim default value) |
11 s (Vissim default value) |
9.25 s |
7.5 s |
Impact of changed weather conditions
|
Attribute |
Bad |
Very bad |
|
Look ahead distance (maximum) |
200 |
50 |
|
Look ahead distance (minimum) |
150 |
50 |
|
Additive part of safety distance (w74bxAdd) Wiedemann 74 model parameters |
+25% |
+50% |
|
Multiplicative part of safety distance (w74bxMult) Wiedemann 74 model parameters |
+25% |
+50% |
|
Wiedemann 99 – cc1 |
Normal: Hr+25% Normal: MV+25% |
Normal: Hr+50% Normal: MV+50% |
Variation of driving styles in consecutive simulation runs
When you change the driving style in consecutive simulation runs, it will affect the surrounding traffic and the simulation results accordingly. Evaluating and comparing these simulation runs and their different results helps in demonstrating and assessing the impacts of various driving styles.
If no vehicle inputs are defined for your Vissim network, you can create a simple surrounding traffic scenario where your ego vehicle will operate during the simulation run (Generating basic surrounding traffic).
