Driver us not observing ongoing the road conditions and adjusting behavior accordingly. Examples of road conditions include:

• Traffic 
• Pedestrians
• Construction

Example 1 

• Inside the red circle the driver can be seen looking to the side, he is not scanning the roadway.
• The truck is moving at 25mph as seen in the green box on the left.
• In the blue box to the left, you can see the time is 01:28:48 PM.
  
• In front of the truck in the red circle there is a bus with flashing lights indicating it is about to stop.
• The time in the blue box on the left is 01:28:47 PM.
  1. This is one second before example 1 above where the driver is not looking at the road in front of him.
     
• Due to the driver not paying attention to the changing conditions on the roadway he could not stop in time to leave a safe distance between himself and the stopped bus in front of him as seen in the red circle.
• Therefore, this video event is marked Not Scanning Roadway in the blue box on the right.