This is one of those issues that keep coming up every few years. Since it keeps coming up, either old solutions aren't working or management didn't pay attention to what used to work and let it lapse.
Pretty obvious that when you see families leaving carrying sleepy kids, and the top class feature race hasn't been lined up yet, those people will never be back. And they will caution their friends about it.
Some track operators are afraid of enforcing rules because that might make racers mad and they'll lose cars. They don't realize that they are probably already losing other cars and multiple fans because of those racers who need to be disciplined.
I've seen a few things work over the years:
Three strikes and you're out. Cause three cautions over the course of the program and you're black flagged. Includes heat races as well as features, and also includes driving in multiple classes.
Cars for the next race are expected to be staged by the white flag of the previous race. At that point, the cars that are staged are moved up in line and stragglers tag onto the back in the order they show up.
Once the field enters the track for its race, there are three caution laps to get everybody together and lined up correctly. (This does not include warm-up laps taken by top classes like Super Late Models.) There is no coming onto the track late and moving up to take a starting position within or at the head of the pack - you tag onto the rear. Refusing to do so results in a black flag.
If a class keeps going long due to too many cautions and restarts, it is moved to be the last race of the night next week.
Time limits (that don't include time for wreck cleanup).
Requiring working racing radios (such as RACEceiver), and drivers respecting and following track operator's instructions issued over it. "Couldn't hear" is no excuse - you are responsible for how well your radio works.
I like the article's rule that states each race will have one final attempt to finish under green flag conditions once the time limit is reached.
Of course, long drawn-out shows can be the fault of track management too. It can't expect to be successful if:
It is still prepping the track within half an hour (or later) of the scheduled drivers' meeting time - especially if the weather had been good before race day.
It waits on teams to show up, or to get their cars prepared and on the track. Not only creates dead time, but also suggests favoritism.
It has to have the announcer come on the PA system to beg cars to get staged.
It has dead gaps between races, and long intermissions, where it appears to fans that nothing is going on.
It has trouble getting its tow trucks to work.
It has track workers - especially the flagman - just disappear for a while.
It allows teams to work on their cars out on the track. Even worse, track workers working on cars while out on the track.
Keep drawing out shows past midnight and you'll see your fan count fall off. Even hardcore fans have limits. Sponsors will notice, and you'll have trouble getting them to sign up again.
But what do I know? I'm only a customer...