Simulation

 

Vissim is a great tool to visualize and analyze highway traffic data. Before running a simulation, assure that each previous section has been implemented. The following section is the most basic method of extracting simulation data from Vissim. I encourage each team to explore the “Evaluation” function/attributes if time permits.

 

Identify where the simulation data will be saved…

  1. On the top toolbar, Select Evaluation > Configuration (see Figure below)

  2. Click the “…” button and select the location/folder as your desired output directory

  3. Click OK

  4. Click OK

To set the Simulation Parameters …

  1. On the top toolbar, Select Simulation > Parameters (see Figure below)

    • Period:                                10800 for 3 hours or 7200 for 2 hours

    • Simulation resolution:     10                    

      • TIP: Higher values = smoother simulations while requiring more resources

    • Random Seed:                  Random #        

      • TIP: Consider changing the seed number every to avoid similar results

    • Number of runs:               1

    • Simulation speed:            maximum

    • Number of cores:             use all cores

  2. Click OK

 
 
TIP: To manually save simulation data, Click the “Save to file” button located left of the “Autosave” button.

  • Select the “Data Collection Measurement” tab below the Network Editor

  • Click the “Autosave after simulation” button

  1. On the top toolbar, Select Simulation > Continuous …sit back and watch the simulation run (see Figure below)

    • If Vissim prompts the user to “Save changes?” Click Yes 

  2. While the simulation is running, make a note of the following vehicular characteristics:

    • Vehicles are entering and exiting through the appropriate locations

    • HGV are generated by the simulation

    • Look for unusual behavior (stuck vehicles, merging issues, disappearing vehicles, unused lanes, connector issues …)

  3. Watch the entire simulation carefully, zoom in and out to locate trouble areas

  4. Let the entire simulation finish to automatically save the results

  5. Values will being to generate in the “Data Collection Measurement” window as the simulation runs

TIP: The "Adjusting Driving Behavior" Section will cover how to adjust certain variables in Vissim to achieve a more representative simulation. Do not stop the simulation midway unless it is necessary. Even incomplete simulation data will be exported automatically.
 

YouTube

The content in the section above has been summarized in the video below.