December 2024 — Technical note #91
Tessa Hayman
Product Specialist
Aimsun Next has a powerful set of view modes that allow you to visualize your data and understand your model effectively.
The view modes can be customized and combined to provide quick, easy-to-see insights that allow for efficient data analysis, model coding, calibration and validation. They also can be used as part of stakeholder engagement to interrogate transport problems and solutions.
This technical note will focus on a use case of creating a set of view modes to understand the potential impact of a traffic scheme on public transport.
To assess the impact of a scheme on public transport it is vital for all stakeholders to understand where the current public transport demand is highest. This can be visualized in Aimsun Next by importing the number of people boarding at each bus stops as a Real Data Set.
1. Late a real data set (RDS) – The first step is to import the bus stop boarding data. This can be added as an RDS by going to project > new> data analysis > real data set. Double click to open your new RDS in the project window. Click Add to add a new CSV to the real data set and select “Simple File Reader”.
2. In the Simple File Reader window, select the location of your csv. Set the ID type to be the external ID of the objects. Set the Object Type to “Public Transport Stop”. Set the time to the correct format. You will need to select a data aggregation interval; this should be the same as your scenario statistical interval e.g. 1:00:00. Make sure to set the column separator correctly and the number of lines to skip for your header.
Add the columns for your RDS. If it contains data that is not needed by the RDS you can use the “Not used type”. Here ID, Not Used, Boarding, Alighting and Time have been set.
3. Add the RDS to a scenario – In v24, it is necessary to add your RDS to a scenario in order to reference it in a View Style. If you have not yet created a scenario an empty one can be used. To add the RDS to the scenario, open the scenario and in the main tab select your
4. Update the statistical interval in the scenario – Ensure that the statistics interval for the scenario is the same as the interval of your RDS e.g. 1:00:00. The statistics interval is found in the Outputs to Generate Tab.
5. Create the view mode – Go to Project > New > data analysis > New view mode. In this window, click “Add New Style”.
6. Customise the view style – In this window, select the new object type “Public Transport Stop” in the “Objects of Type” dropdown box. Set the Style to “Spot” and the attribute to “Boarding”. Then add rows for each spot style you would like to have using the “New” button. Once you have selected the colour and size of each spot press OK.
7. Add a second view style to add a label with the number of passengers – In the same way that the first view style was created, add a second view style from the view mode menu. Set the style to: “Attribute” and select your preferred colour for the label.
8. View the results – Once you have created both view styles, click okay on the view mode menu. Then select the view mode at the top of the window. It can be easier to see the results on a grey background, to do this go to view > grey mode.
You may want to visualize the locations that people want to visit and the potential demand from these locations. You can import locations as points from a GIS output such as a shape file. Fields from the shape file can be visualized in a similar way to above to then show the number of pupils.
1. Import the schools as points – If you have a shape file which contains your schools with their number of pupils you can import these as a new object type. Go to Import > GIS and select your shape file. In the next window: select import as internal layer; create a New Type and name it “School”. Make sure to tick the box “Copy GIS Attributes in Generated Objects” as this will create our attribute for the view style.
Example of importing extra toll costs in Aimsun Next as new section attributes: “SATURN tolls 1”, “SATURN tolls 2”, “SATURN tolls 3”
2. Make the view mode – Go to Project > New > data analysis > New view mode. In this window, click “Add New Style”.
3. Customise the view style – In this window, select the new object type “school” in the “Objects of Type” dropdown box. Set the Style to “Spot” and the attribute to the column in your shape file containing the demand e.g. “Demand”. Then add rows for each spot style you would like to have using the “New” button. Once you have selected the colour and size of each spot press OK.
You may then wish to visualize which public transport lines have the highest frequency. When PT lines are created inside Aimsun Next, a set of polylines are added to the layers with one polyline for each public transport route. You can use a view mode to colour these by route number and then change the width of the route based on the frequency of this route.
1. Run the model – Run a meso or micro simulation with the Public transport plan active. This will give each PT line an output that represents the number of vehicles per hour that serve that line during the simulation period.
2. Make a new view mode and within it two new styles will be created. One to colour the PT lines and the other to set the bar width.
3. Make view style 1 – Set the object type to “Public Transport line”, the style to “colour” and the attribute to “ID”. By clicking the button calculate ranges, and selecting unique values you can generate all your rows for each individual line. Then use the colour ramp at the bottom to quickly assign a colour to each PT line.
4. Make view style 2 – Set the object type to “Public Transport line”, the style to “width” and the attribute to “Input Flow”. Add a new row – set the width as 1-20 and tick proportional. This will then set the width of the public transport line proportionally to the frequency of the service measured in veh/h.
Once you have created a set of options on how to improve the public transport network, you may wish to compare the outcomes visually. For instance, you may wish to understand how the delay time per section along a corridor is impacted by a scheme for all vehicles as well as for just public transport vehicles.
Stakeholders can then use this thematic map to understand which schemes may perform best. You can create a view mode that colours sections based on the change in delay time between two scenarios.
1. Compare two scenarios – You can compare two scenarios using the data comparison tool. Go to data analysis > data comparison. Select the two scenarios and set the object to section. Select delay/travel time in the reference data and click compare. This will then create a new attribute in the sections with the relative and absolute difference for the delay/travel time.
2. Create a new view mode and view style – In the view style select the object type “Section” and style “Colour”. Create rows for each colour band required.
3. Create a second view style – A second view style can be added which will make the sections grey if the two compared values are the same and change the width of the output where the compared values differ. To do this set the object type to section and style “Stacked Bands”. Create four rows as shown below. Set the Bar width for the non infinite rows to 40-4 and 4-40, making sure to tick the “Proportional” box. This will give sections with a higher delay/travel time a larger width.
Then move the attributes common value and absolute difference to the selected columns using the green arrow. Set the colour to grey and black. For common value, tick the box “Use colour” this will colour the stacked band based on the previous view style.
To understand the impacts of the delay time on public transport we may want to know what proportion of general traffic is made up of public transport. This could help you to design new options such as rerouting public transport to avoid queued buses at stops or to understand whether an increase in delay time may be preferable to achieve the vision of the road operator. You can create a view mode that creates a pie chart for each road section if the delay/travel time is greater than 10%.
1. Make a new view mode and view style – set the object type to “Section” and style to “Diagram: Pie”. Set the diagram size and size units – here 150m has been used. In the selected columns window, select flow – adding a row for each vehicle type. Set a colour for the public and private vehicle types.
2. Add a filter – to add a filter go to the Conditions tab and set the condition delay/travel time for all vehicle types in all lanes to be greater than 10.
2. Add a filter – to add a filter go to the Conditions tab and set the condition delay/travel time for all vehicle types in all lanes to be greater than 10.
SHARE
Aimsun Next 24
Aimsun (2024). Aimsun Next 24 User’s Manual, Aimsun Next Version 24.0.0, Barcelona, Spain. Accessed on: April. 16, 2024. [Online].
Available: https://docs.aimsun.com/next/24.0.0/
Aimsun Next 24
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title = {Aimsun Next 24 User’s Manual},
author = {Aimsun},
edition = {Aimsun Next 24.0.0},
address = {Barcelona, Spain},
year = {2024. [Online]},
month = {Accessed on: Month, Day, Year},
url = {https://docs.aimsun.com/next/24.0.0},
}
Aimsun Next 24
TY – COMP
T1 – Aimsun Next 24 User’s Manual
A1 – Aimsun
ET – Aimsun Next Version 24.0.0
Y1 – 2024
Y2 – Accessed on: Month, Day, Year
CY – Barcelona, Spain
PB – Aimsun
UR – [In software]. Available:
https://docs.aimsun.com/next/24.0.0/
