I agree with the three hour show for a number of reasons. I sometimes try to get to a new track as way to break up a scheduled trip where the final destination is not the race (such as visiting family in another state). When getting to the track, I generally only have a few hours before having to get back on the road. There is no way that I want to spend 7 hours at a track with another 3 or 5 hours of driving remaining. This is one of the reasons why I tend to like special shows, as they typically have 2 or 3 divisions on the card.
I do organize trips to racetracks by looking at the number of divisions on card. For this reason I haven’t been able to squeeze a trip to Outlaw Speedway, which runs numerous divisions and is known for going all day and late into the night.
Also, if I bring someone new to the races, it is a lot to ask a first timer to hold attention for anything more than three hours. It’s better for these folks to have quick exposure to local racing and take away a positive experience than to sit all night.