How to Draw Line Segment Zones

This guide will show you how to make line segment Zones in StreetLight InSight via drawing the Zones. Line segment Zones represent portions of the road network. They can be used to capture traffic traveling along roads of all types, including highways, freeway ramps, and city streets. Once line segment Zones are added to StreetLight InSight as a Zone Set--either by drawing or uploading a line shapefile--they can be used in various Project Types, including O-D Analysis, Zone Activity Analysis, Segment Analysis, and Traffic Diagnostics.

When a line segment Zone is added to StreetLight InSight, a number of items are stored with the Zone:

  • The original line shape.
  • The start point
  • The end point
  • A start gate: a polygon Zone created at the start point drawn perpendicular to the line. This gate along with the end gate is used in Segment Analyses and Traffic Diagnostics projects.
  • A middle gate: a polygon Zone created at the midpoint of the line drawn perpendicular to the line. This gate is used in O-D type analyses.
  • An end gate: a polygon Zone created at the end point drawn perpendicular to the line. This gate along with the end gate is used in Segment Analyses and Traffic Diagnostics projects.
  • Direction information.

Note: You can also create Zones by uploading or drawing polygons. Learn more [LINK] about drawing Polygon Zones.

Create Line Segment Zones Using the “Draw” Tool

In this section, we will draw a Line Segment Zone on a bridge in Richmond, VA.

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: Name your Zone Set.

Step 4: Select Line as the Zone Set Type.

Step 5: Click the “Draw New Zone” button.

Step 6: Zoom in on the map using an address, latitude/longitude coordinates, or a point of interest.

Step 7: Turn on the OSM Layer. When drawing any kind of Road Zone, it is important to check the box to “Show OSM Layer.” The OSM (which stands for OpenStreetMap) road layer is what StreetLight InSight uses to lock trips to the underlying road network. Zones must cover the road segments that they represent in the OSM layer in order for StreetLight InSight to analyze the trips that use the road.

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

Step 8: Left-click once on the map to establish the beginning of your line, and left-click as many times as necessary to follow the road. Double-click to mark the end of the line segment Zone.

Step 9:  Name the Zone and optionally give it a Zone ID.

Step 10:  Line segment Zones are always marked as Pass-through.

Step 11:  Choose if the Zone will be bi-directional or uni-directional. A bi-directional Zone will analyze trips in both directions represented by the road. A uni-directional Zone will analyze trips only in the direction of the start to end of the line. Learn more [LINK TO ALL ABOUT DIRECTION]

Step 12:  Select the Road Type. When the line segment Zone is saved, StreetLight InSight creates a series of small polygon Pass-through Zones (or “gates”) at three specific points on the segment: at the beginning, middle, and end. The Road Type determines the widths of the gates that are automatically drawn. Choose from the following Road Types:

  • Primary = Freeway / Highway
  • Secondary = Arterial (takes traffic into / out of a freeway)
  • Ramp = ramp to / from a highway.
  • Local = street roads, and all other roads.

Note: You can later edit the Zone to modify or redraw any or all gates. Learn more. [LINK TO EDITING LINE SEGMENT ZONES]

Step 13:  You also have the option to add Calibration Data to any Zone. This allows you to use our Calibration Feature to get estimated traffic counts for your Project. Learn more. [LINK CALIBRATION GUIDE FOR DRAWING]

Step 14: Click Save on the Zone.

Step 15: Click Save on the Zone Set.

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 14: Review all the Zones before using in a Project. In order to accurately capture traffic, line segment Zones require a high level of spatial accuracy. Before using your line segment Zone Sets in a project, you’ll want to confirm that your gates correctly overlap the underlying road network. Learn more on reviewing and editing Line Segment Zones. 

Pro Tips 

  • When drawing your line segment, click the “Show OSM Layer” button in the upper right-hand corner of your map. This will display the OpenStreetMap layer, which is used to lock vehicle trips to the underlying road network. The OSM lines, displayed in pink on your map, will help you confirm whether your line will accurately capture traffic.
  • If you are creating a Zone Set and would like to make sure that you are drawing the Zones on the boundaries of another area of interest, use the tool called “View Other Zone Set”. This allows you to draw a new Zone while visualizing another Zone Set.

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

 

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