Let's face the facts---the Amherst Show is so popular that the crowds come, buy their ticket, and come in. It's not just for rail enthusiasts, but for potential enthusiasts including those in baby strollers who keep the marketing cycle going and manufacturers providing. I don't know why anyone is debating the crowding issue or quoting a Chapter 140 law that says nothing about building capacity, a relative factor considering a formula based on square footage the show organizers have little to do with. That's just the way it is. We can't have it all.
Every one of 20,000+ attendees there paid the admission to see and enjoy. Bear in mind all weren't ALL there at the same time! Every attendee also deserved the right to stand close to displays and then move on for the next person to see and enjoy. Everyone patiently takes their turn. In over 20+ years of my own attendance, I've gotten used to it and found numerous opportunities to find the times where I can look, browse, and buy at my leisure.
The organizers have gone above and beyond by increasing aisle space and through that limiting some vendors who are on a VERY long waiting list. Forget about having a fourth building unless A--you are willing to help staff it and be "paid" with a free admission you "might" take advantage of to actually see the show, or B--put up with a walk of about a quarter of a mile to the next available building. I can hear those complaints now! I seriously doubt if any exhibitor would want to, or could endure staffing or conducting a 3-day show. Most exhibitors rarely get to enjoy a good walk around. For an $8 admission price plus the $5 charged by the BigE for parking, this show is a bargain compared to other shows held there, and it's the biggest two-day show that happens only once each year. Just be glad it happens. Better yet, get the opinions of all the people who might finally get all their displays packed and on the road home about 9 PM on Sunday, long after you went home and the show closed.