There is really no need for the show to run pass 3 hours except for weather and a few other issues. The top class that most fans are there to watch should be run during a 2 and a half to 3 hour window after the show starts. Most people attention drops after that.
If they run more than 3 divisions make sure the top class is on the track by a certain time of night. It gets frustrating to watch divisions will poor car counts or support division crash fests keep fans waiting till some late hour of the night. Less than 10 cars for a feature should be run last or be cut out of the program for good. Also the crate, sportsman or other classes that wreck 4-5 times at the start of the race or take 60 minutes should be parked till the end of the night.
Lets face most of the die hards or die off and racing may die out shortly. When the tracks are gone either someone is going to find a new hobby, watch video of old races or talk about the past. When the tracks are all gone their is little we can do ! But a bunch of tracks could last longer if they provided better value for the fans.
For the most part Jersey tracks seem to get this right most of the time.