With a background image as a reference, we demark the portions where vehicles (or pedestrians) move. An example of how to create Ways on a map is given here. It is the same way-creation process explained in earlier sections, but instead of randomly clicking over space, we Ctrl-Click on spots that match the road or path seen in the map.
Consider a case of the image shown below, a junction (or intersection) in Purdue University Campus (Purdue, USA). It is a straightforward case where two roads cross and form a junction. Remember, MSV does not use links and nodes but Ways and Streams. We create Ways and set up Streams over those Way objects.
Sample junction used to show how (or where) the Ways are created.
To begin with, we assume that the image is scaled properly using the procedure described earlier. It is also assumed that you know how to create a Way and modify the control points of it, as described in earlier sections.
The road portion of one approach leg of the intersection is marked in the following picture. Way is created with a Ctrl-Click on the starting point of that portion. A blue blob appears where we clicked.
First Way being created on an approach leg of the junction
A series of Ctrl-Clicks were made (usually four or five points are sufficient for a small section; more points may be required if the stretch is longer). Points should be spaced realistically to match the road or path. Avoid too closely spaced points unless in truly straight portions. More points are needed in curves. The program will alert you if points are too close for curve creation.
In this case, the approach to the intersection from the left edge of the map to the two cars near the stop line is divided into two Ways. Note that the width changes (just above the word Stadium in the map). Whenever such changes occur, create more than one Way. Streams will connect them later. There is no need to physically connect the Ways.
A Way created for the starting portion of the approach road to the junction.
If the image is too bright, the lines forming the Way may not be visible, as shown below. The question mark in the picture highlights the issue.
Often, images are too bright, hiding the Ways.
Adjust the Glare value in the BGM Editor to reduce brightness. Save and reload the model first. Then, open the BGM Editor. The Glare value can be set from 0 to 1 (e.g., 0.5 or 0.6 for Google images). Avoid modifying the Scale field unintentionally. The result after adjusting the Glare is shown below:
The Way is visible now after reducing the brightness of the background map/image.
Once a Way is created, fine-tune its position or orientation by adjusting its control points as required.
Fine-tuning control point positions.
The second portion of the approach road is marked below. A new Way is created approximately along the centerline of the approaching direction (not the road's centerline, which includes a lane for the opposite flow). Create separate Ways for each direction of flow.
Way being created for the second portion of the approach leg
The number of lanes is set to 2 to match the map:
This Way portion has two lanes.
Another Way is created for the opposite side of the junction. The same procedure is repeated for all roads in the modeled area.
One more Way, this one on the East side of the junction
Once all Ways are created, this is how they appear on the map:
Ways on the Map
If the BGM is hidden, the Ways will appear as shown below. Initially, it may seem incomplete, but Ways are only one of the three essential entities in MSV for mobility simulation. The other two components, Streams and Flows, are described in other sections.
Ways shown without the BGM image
A pavement base can also be created to fill road areas using polygon objects (explained in subsequent sections of the manual):
Pavement base for the Ways