How to Save 95% of Your Time on Vissim Traffic Model Calibration With GoodVision

Traffic model calibration is a time-consuming task

At GoodVision we are extremely focused on exploring traffic data for the good of the whole transportation industry. By working with experts from TOP-tier transport planning organizations like Jacobs, Atkins and PTV Group, we aim to deliver a better and easier working experience on traffic projects to you all!

One of the most crucial and time-consuming tasks in the traffic analytics process is traffic model creation in the simulation system. Depending on the intersection's complexity, this task takes hours or days of the urban planner’s manual effort. It consists of:

1. Creating a micro-network for each intersection
2. Connecting the micro-networks into a complex traffic network
3. Calibration of each intersection model with traffic volumes, speed, etc.
4. Verification of the model against the real-world situation

GoodVision saves 95% of your time with traffic modelling

One of the major goals of GoodVision Video Insights platform is to save traffic modellers their precious time on repetitive manual tasks. GoodVision is the pioneering solution that is able to do it from the digitally extracted traffic data from the traffic video survey. In the current product version 23, PTV Vissim users are supported.

How do you like the new process below? Just imagine:

1. You describe your traffic scene
2. Auto-generate traffic model for export
3. You get the *.inpx file with the model within seconds
4. You import the model into the PTV Vissim, while the links and routing decisions in your model network are already calibrated by traffic counts and vehicle speed from GoodVision Video Insights

This method not only saves time, but also significantly helps to eliminate the human error when copy-pasting the traffic parameter values from Excel sheets to your model during calibration, or obtaining it elsewhere.

Defining your traffic scene for model generation

Any type of junction is supported. All you need to do is “describe” the traffic movements on your scene, which will be exported to your model. To learn how to describe your scene, read our article here.

Note: When placing your lines to the scene (do not use zones here), make sure to draw only a single line across the road with the multiple lanes. Do not draw lines for individual road lanes if the lanes are going into the same direction.

Finally, you will define the traffic movements to include in the future model. If you are looking to calibrate your future model by vehicle speed, provide a distance measurement to every traffic movement created. Learn more about how to enter movement distances.

Describe Scene page in the GoodVision Video Insights

You can easily get the distances from Google Maps using the “Measure Distance” function, even for the turning movements.

You can easily get the distances from Google Maps using the “Measure Distance” function.

Configure and generate your Vissim model

The generation of the model file is simple. On the ‘Describe scene’ in GoodVision Video Insights click ‘Generate model’ button, which opens the configuration window:

• Choose the vehicle classes to include in the model (Vehicle Types in Vissim)
• Choose which traffic movements will be exported as a part of your model and will become Links in Vissim
• Choose if you want to calibrate links by speed (if you select no, the Vissim Default Speed Distributions will be applied in the model)
• Choose the survey time interval to take calibration parameters from the survey analysis — the peak hour is selected by default, but you can choose a custom time range
• Choose the time unit to distribute volumes and vehicle compositions into the Vissim Vehicle Inputs, Vehicle route decisions and Vehicle compositions of the model, 15-minute intervals are selected by default
• You may want to insert the latitude and longitude of your junction, so your model is placed on the correct map position immediately

This is the Vissim model generation dialogue in GoodVision Video Insights

After you confirm the settings, your model will be generated and you receive the .inpx file within a few seconds.

Your Vissim model *.inpx file will be accessible in the Traffic Exports section in the platform

Import your generated traffic model to Vissim

Once you have the *.inpx file generated in GoodVision Video Insights, you can open it in your PTV Vissim or AIMSUN system. You can import multiple isolated network models from GoodVision and connect them into a more complex network in Vissim. Every model generated by GoodVision is calibrated by default, plus it allows to adjust the values manually as you are used to.

Optional step: After opening the .inpx file, generate the spline for connectors (links), adjust the position of the prolonged links or increase the number of lanes in each link if needed (by default every link has 1 lane)

IMPORTANT NOTE

The camera scene might be rotated or distorted based on the original camera view. When generating a model be aware that perspective and real orientation of the camera might cause distorted links which must be adjusted in Vissim as on the video below.

Adjusting the generated links and connectors is done in a few seconds

Conclusion

GoodVision automatic .inpx file model generation is a time-saver for all traffic modellers that work with the PTV Vissim simulation software on a daily basis. It eliminates possible human error when calibrating the model with many parameters that need to be inserted manually otherwise. It allows the user to create an exact digital twin of the real scene in Vissim.

Vissim model generation is a premium feature available in the Traffic Modeller platform plan. You can try your own video traffic analyses in GoodVision Video Insights right now at my.goodvisionlive.com

In case you have more questions or insights regarding the Vissim model generation contact us on info@goodvisionlive.com 👍