Transportation Systems Simulation - A Tutorial for Multi-Modal Simulation Using VISSIM/Background Image and Map
There are two basic methods of incorporating a background image/map in VISSIM. Either by importing a background image or by using the maps provided by VISSIM.
- Background Map: VISSIM has multiple integrated map services
- Click on the Multicolored Wrench Button (Edit Basic Graphics Parameters) to choose a map provider (see Figure below)
- Consider using “Bing Maps” (Aerial View) or “OpenStreetMap” (Mapnik)
- Click on the Down Arrow to bring a drop-down menu
- First select the “OpenStreetMap” to locate the desired section of highway by using the “Zoom” tools
- Once you have found the exact segment of highway, Click on the Multicolored Wrench Button again to choose the map provider “Bing Maps” for an aerial view
TIP: Look for identifiable cities and freeways to quickly find the desired section of highway. If the map does not appear automatically after its selection it might be toggled off, Click on the globe button (Toggle Background Maps). Consider using a background map provided by VISSIM instead of importing a background image. This will reduce the resources required by VISSIM and increase the accuracy of your image since scaling or stitching is not required.
- Select the "Background Image" option from the Network Objects panel (see Figure below)
- Right Click the mouse anywhere in the Network Editor you wish to place your image, then select "Add New Background Image" (Shortcut: CTRL+ Right Click)
- Select the file(s) you wish to import, then click Open
TIP: Use the smallest file size possible while keeping an adequate amount of detail in the image. Using large files will use more computer resources as you design your network. If the original image is formatted as a PNG image (.png), try reducing the file size by opening the image with Microsoft Paint and saving the image as a JPEG image (.jpg)
Set the Scale
The following section will describe how to scale and connect multiple images together to make on large map. The background image must be scaled to get accurate results
- Find two points where the distance is known, and then use the “scale” function
- In your project, the precise distance can be found when you load the map named “scale” (see Figure below)
- The “scale” map indicates the precise distance of 50 feet
- If a background image does not have a scale, use the width of 4 consecutive lanes (12ft x 4 = 48ft) as your reference points
- To apply the “scale” function, Right Click the mouse on the desired image and select "Set Scale"
- The cursor will turn into a cross (+). Zoom into the map named “scale” and find the portion of the map that indicates the precise distance of 50 feet.
- Find the starting point of 50 feet, Left Click and Drag the mouse to the second point, release the left mouse button
- Enter the distance in feet (50 ft.) and Click OK. As you drag the mouse, a ruler will appear as a yellow line.
Stitching Maps Together
After scaling every image, connect them together according to their sequence in Google Maps.Since there are overlaps between two sequential maps, you need to carefully check Google Maps and combine each image in the perfectly position (see Figure below)
The content above is also available as a video. Click the following YouTube link: VISSIM v7 Tutorial Part 2: Maps