Dale Earnhardt's death is a benchmark for the new era of NASCAR. Since February 2001, NASCAR has made many changes in order to improve racing, safety, and image.
Dale's death created a concerted effort to make the series much more safe for the drivers. This includes better helmets, restraints, cars, and facilities. They have all helped to make the racing much safer.
Also, the series has recently changed title sponsors, and the sanctioning body hopes that is will make the series even more popular and interesting to people from all walks of life.
And there has been the latest and most debated change: the new COT. The car is a safety marvel, but it has disillusioned many fans that feel the series is moving too far from its roots.
Overall, we can trace the root of many of the recent changes in NASCAR to the death of the legendary Dale Earnhardt.