Augmented Reality application for drivers

Here is an iPhone augmented reality application for car drivers. This application was made by a company called imaGinyze. This application detects the lane in which you are driving and the vehicle that is ahead of your car. This application mainly uses spoken notifications to provide the driver with warnings of any potential hazards. My concern is how this application might work in a traffic jam, on narrow roads, or on a road that does not have clearly-marked lanes.

Here is the video clip.