This article goes through the process of using an existing strategic transport model in CUBE Voyager to create a mesoscopic transport model in CUBE Avenue, thereby moving from a macro to meso scale.
Mesoscopic Models are generally used for congestion corridor analysis at regional subareas or at a corridor level. Among the outputs of a Mesoscopic Model with CUBE Avenue we have:
The procedure we will take in this article consists of four main steps:
Let's get started.
Open from the tutorial model download (A very simple 25-zone Model created for this demonstration) the Macro2Meso(.cat) Catalog File
If we select the Hide unused files for Program the Path File should continue to be visible.
(remember the comma if going on a separate line)
If your Polygon needs to be edited, click on Restore this will allow you to drag around the points to its new location.
Once you have the polygon ready
A ‘Sub-Area Extraction Node Renumbering’ window will pop-up. (You can keep the default numbers for the ‘Renumber Option’ or change them).
You will need a corresponding matrix to be the input of the sub-area. To do this:
If we look in our ‘Base’ folder we will now find a network (.net) and a matrix (.mat) for our sub-area.
If we open the Network file we can see what our sub-area looks like. You can play around with the Post Node tools to change the display of the sub-area (e.g. Show number of zones)
Once the Module is launched, we need to select the inputs and create 2 output files.
The output files will be a Network file and a Packet Log (*.LOG) file.
A good practice is to always create a Print File too, therefore repeat the same procedure for the (*.PRN) file as well
After ‘Hiding Unused Files’ the model will look like this:
To create the Mesoscopic Model:
We will then have to do a few changes to the new script:
Parameters:
TIP: CTRL+ALT+SPACE to auto-create keyboard
LINKREAD phase will remain the same.
ILOOP Phase:
For each link we will have 4 volume sets for each time segment. This means that VS1_1 in the table shows I will have 11.55 vehicle units for the first 15 minute time segment and so on for the rest of the volume sets.
In the table you will also find queue information as well as block information for each link.
Avenue allows us to perform an animation:
The animation will allow you to understand how congestion happens according to the different time segments.
If you need to make changes:
If for example you only want to see the packets leaving from Origin 1-7 and Destinations 8-11 you can make those changes in the ‘Packet Animation Options’ window.
In this case red packets are originated from zone 1-7 and are going to 8-11.
You can also increase the speed to better visualize and understand bottlenecks in the corridor.
You can also play around with dynamic bandwidth plots and view volumes at junctions. Go play and have fun!