How to Draw Polygon Road Zones

This guide will show you how to make polygon Zones for road segments in StreetLight InSight via drawing the Zones. Polygon Zones for road segments are Zones that are always designated as Pass-through. They are used for turning ratios, corridor studies, select links, and so much more. Think of this type of Zone as a “gate” or digital sensor line on the roadway that analyzes the trips that pass through it.

This guide describes drawing polygons If preferred, you can use Line Segment Zones to analyze road segments instead of polygon Zones which can also be drawn or uploaded via shapefile. Learn more about drawing line segment Zones. 

Create Polygon Zones Using the “Draw” Tool

In this section we will draw a polygon Zone. Our example is from turning ratio study for a bridge in Louisville, KY.

Step 1:  Navigate to the “Manage Travel Projects” tab section of your StreetLight InSight account, which is located in the upper left hand corner under the menu icon.

Step 2: Navigate to the “Manage Zone Sets” tab and click the “Add Zone Set” button.

Step 3:  Create a name for your Zone Set. Keep “Polygon” as the Zone Set Type.

Step 4: To create a Zone, click “Draw New Zone.”  

Step 5: Create your Polygon Zone. This works best if you draw gates across the road, but be careful not to catch any neighboring roads in your gate.

Pro tip: You can zoom in on the map using an address, latitude/longitude coordinates, or a point of interest.  

Step 5: When drawing any kind of Road Zone, it is important to check the box to “Show OSM Layer.” The OpenStreetMap road layer is what we use to lock our trips to the underlying road network, and the Zone must cover this layer to pick up trips traveling along the road.

Note: If the OSM Layer is not available, zoom the map in further.

Step 6: Zoom to the road you want to analyze. Left-click with your mouse on the map to create a small rectangular “gate” over the road of interest. The “gate” is drawn as though laying a rope across the road.

Note: If you wish to start over on the polygon, click the “trash can” icon to clear the polygon.

Step 7: Since you’re looking to capture activity along a road, you’ll need to make the Zone Pass-through. Pass-through means that any trip that enters and exits the polygon Zone will be included in your Metrics. A non-Pass-through Zone will only count trips that start or end in your Zone.

Making the Zone Pass-through is critical to capturing activity along the road. If you were to update the Pass-through setting to “No,” you would only capture trips that start or stop on this small portion of the road, and would likely return very few trips.

Step 8: After marking the Zone as Pass-through you will have the option to add a direction to your Zone. Learn more about direction.

8a: Click “Draw Direction” before you save your Zone.  

8b: Click once on the map to create a “start” pin, then click again to create an “end” pin. You will see an arrow that designates the direction of travel.

Note: To indicate a different direction for the zone, click the “Clear Direction” button and then start over with Step 8.1.

Note: You can reverse the direction of the zone with the “Reverse Direction” button. This will swap the start and end points for the direction.

8c: You will then have the option to choose if the roadway is Bi-directional. Choose No if you wish to analyze traffic in only the direction indicated. Choose Yes to analyze trips that pass through your Zone in either direction. 

Step 9: You also have the option to add Calibration data to any Zone. Adding Calibration data to your Zone will allow you to use our Calibration Feature, which provides estimated traffic counts for your projects. Learn more about the Calibration feature.

Step 10: Save your Zone.

Note: You can add more Zones to the Zone Set by repeating the steps above. We recommend you save the Zone Set after the creating the first Zone and then editing the Zone Set to add more Zones. This approach will prevent loss of effort in the event of an interruption to the session.

Step 11: Save your Zone Set.

Pro-Tips

  • One way to confirm that your Zone will cover the intended complex traffic patterns is to turn on the OpenStreetMap layer when drawing your Zones. Again, this layer is what StreetLight InSight uses to lock trips to the existing road network. On occasion, the OpenStreetMap road network might differ slightly from what is depicted on Google Maps or Satellite views. For this reason, it’s always a good idea to reference the layer by checking the box “Show OSM Layer.”

  • If you are creating a Zone Set and would like to make sure that you are drawing on the boundaries of another area of interest, use the tool called “View Other Zone Set”. This allows you to draw a Zone while visualizing another Zone Set.

  • If you are working with an account with a boundary region or a study and would like to make sure that you are drawing within the boundary, check “Show Subscription Region” or “Show Study Region”. This will display the region as defined for your account. (Kansas City in the example below).

 

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