The construction zone assist system keeps the car within a narrower lane by way of steering corrections.
To do this, the system takes data from video and ultrasonic sensors and calculates a safe distance on either side to vehicles in the next lane as well as to any crash barrier.
This system may also over-ride traffic control data in the map or navigation system, such as speed limits, and use the forward facing camera to additionally detect temporary speed limits and other non-permanent infrastructure changes, such as cones, etc.
The video sensor also measures clear spaces ahead of the vehicle. This enables the system to provide a timely warning in case the lane in a construction zone is too narrow for the vehicle.