Availability Heuristic

In this clip about estimating risk (the availability heuristic) ABC News describes how road rage is running rampant. Bob Lichter explains that the media over-dramatizes reckless driving.

According to an AAA study, road rage is up 51%; however, these reports were based on media reports. The AAA representative explains that we are more likely to pay attention to salacious reports. Define availability heuristic. How do the media use the availability heuristic in this example?