After your video is successfully processed in a Data Source, you can start with the analysis. On the Describe scene page, you’ll see a screenshot of the traffic scene with coloured vehicle trajectories representing the movement flows for each object class on the scene. For videos up to 1 hour long, all trajectories are shown on the preview screenshot. For longer videos, you’ll see an average 1 hour trajectory sample.
On the first sight, you can already gain some first insights about the traffic scene. To get various kinds of metrics and visual maps for your further traffic analysis, the necessary step is to define the conditions on the scene - set entries and exits, desired movements and areas which you are interested in. The whole process is simple and it’s enough to do it just once per camera.
After you're done, you can create various analytical widgets or reports based on your interest (traffic volumes, travel and occupancy times and more) or upload more videos with the same view to the same Data Source. With settings and filters already in place, you can get the traffic data easily via a few clicks to your widgets' dashboard.
STEP 1 - Place the virtual zones and lines
On the Describe scene page you can draw virtual lines or zones on the scene to cover movements or events that you want to include into your traffic analysis. Describe scene page displays exact traffic trajectories which will help you to draw lines or zones to the right places of interest. Lines are usually good for defining entries, exits and movements between them whereas zones are used for stay or stop events, occupancy time and else.
The image below shows an example of how the lines and zones can be placed for a basic traffic analysis of an intersection using the line and zone creation icons on the upper left corner of the Describe scene page.
Picture 1: A possible scene description of an intersection
Check out some tips and recommendations regarding filter placement here.
STEP 2 - Define Traffic Movements, Events, Scenarios
The most common way to describe traffic behavior on the scene is by defining the traffic movements. Movements allow you to filter traffic objects that are driving the selected path. That is a necessary baseline for all kinds of analyses, from traffic volume counting to advanced analyses of travel time, saturation flows and more.
A movement can be created for a single line or zone or for a path consisting of multiple line or zone crossings, depending on your needs. One line or one zone crossings will give counts for all objects regardless of their direction, whereas by multi line/zone movements only objects going the specific direction are filtered.
Example below filters traffic objects (trajectories) that were crossing the line North, then the Approach zone and then the line West in that specific order. For more information, click below and read the full article describing traffic movements in detail.
Picture 2: Example of a movement crossing 2 lines and a zone
The second option for defining specific traffic behavior conditions is using Events. Events allow you to create advanced conditions to your filters and scenarios (e.g. filter traffic objects by occupancy time in a zone, filter only the vehicles that stopped in the area).
Example below filters traffic objects that were staying in the middle of the intersection (zone5) for 5 to 35 seconds. For more information, click below and read the full article describing events in detail.
The third option for defining the traffic behavior is to create a traffic scenario that allows for combining various movements and events into complex conditions. Scenarios use simple logic operators AND, OR, THEN, and NOT. With this tool you can easily filter the traffic trajectories for the most complex traffic situations you can think of.
Example below filters traffic objects that followed one of the defined traffic movements AND were occupying the middle of the intersection for more than 15 seconds. For more information, click below and read the full article describing traffic scenarios in detail.
STEP 3: Getting the traffic data reports
Finally to analyze the traffic data defined by your movements, events or scenarios, you can create appropriate widgets on the Analyze page or reports for desired movements using the Report Builder.
See our guide on How to create widgets for the traffic volume, travel time, peak periods or various visual maps to get the most of the Video Insights platform.