Why aren’t more roller coasters plus-size friendly? Here’s why and what can be done.

Pamela Denman knows, “The world is not made for me,” so she tries to make it more inclusive for others.

Over the years, the self-described “Plus Size Fairy Godmother” has racked up hundreds of theme park visits and built a wealth of firsthand knowledge, which she shares online as Pammie Plus Parks. One of the questions she addresses regularly is which rides are ”fat friendly.”

While minimum heights and other types of requirements can be readily found on park websites, she said, “There is no tab that you can click on that's going to give you information that's helpful to a person of size. That's something you need to find through other resources, usually from other people of size who have experienced the parks themselves.”

Many theme parks offer test seats for thrill rides, so guests can determine if they fit before waiting in line and risking the “walk of shame” if they’re turned away, but even then it’s not cut and dry.

“I’ve gone on a ride and I fit in the seat, the restraint comes down, but there's something about the ride itself, where the movement of the car and maybe the restraint, the way it’s positioned, where it's just really uncomfortable, and it’s scary,” Denman explained. “You know you're safe. You know you're not going to fall out of the vehicle, but it's scary because you're worried about, ‘Is my body going to be injured when I get out of this? Am I going to have bruises? Am I going to be able to walk around for the rest of the day?’ ”

The bigger question is perhaps why more attractions aren’t made to accommodate larger guests when the majority of U.S. adults are considered overweight or obese. To find out, USA TODAY spoke with several leading attraction manufacturers and industry experts:

Safety first

“Our goal is to include everybody, as much as we can,” said Jacob Kilcup, director of Design and Engineering at Rocky Mountain Construction, which created ArieForce One at Fun Spot America Atlanta and Iron Gwazi at Busch Gardens Tampa Bay. “Obviously, though, safety's paramount. These are large, aggressive machines so we have to make sure that these are designed in a way that the rider has the capability to ride and ride safely.”

Passenger size is one of many elements to consider.

“You’re designing the seat to be comfortable, but also to withstand (G) forces and how the forces act on the body,” said Har Kupers, CEO of Vekoma, whose rides include Walt Disney World’s TRON Lightcycle / Run and Dollywood’s Big Bear Mountain.

Kupers, who started off as an engineer, said restraints need to be both strong enough to withstand those G forces and capable of containing passengers amid them because “when the restraint is gone, when there’s a gap or whatever, you’re done.”

He said calculating the strength is easy. “If you have a guy from 100 pounds (to) 300 pounds, doesn't matter.” He said what’s challenging is containment for passengers of different sizes. “Even if the restraint is strong enough, how could people escape from that seat?”

Are theme park rides safe? What you should know if you're worried about accidents.

One size doesn’t fit all

Most attractions are designed to accommodate the widest range of guests in each seat.

“The harness system you design has to work for that youngest, the smallest size that is allowed to go on that ride, but you also have to look at the largest person that you're going to have,” said

Jim Seay, president and owner of Premier Rides, which designs and manufactures attractions for the likes of SeaWorld, Universal Studios and Six Flags.

Seay, whose background is engineering, chaired the International Association of Amusement Parks and Attractions Global Safety Committee and ASTM's Committee F24 on Amusement Rides and Devices, a global committee that sets industry standards for attraction safety.

“You could make it bigger and then restrict the younger people or smaller people from riding the ride,” but he said that could take away some opportunities for intergenerational families to experience rides together.

But Denman said, “That family-friendly ride isn't really so family friendly if everyone in the family can't go on it.”

“I'm used to it in the body that I'm in,” she added. “But my family and friends don't really get that … and it can be very disappointing for your family or your travel group when you can't enjoy things with them.”

'Not my fault there's not enough space': Plus-size travelers share struggles, show strength

Why not offer different sizes?

It is possible to design different types of seats for the same ride, as Vekoma did for TRON, primarily for people with disabilities.

“I would like to see that continue with rides going forward, that there's an adaptable vehicle that's more accommodating for people who have disabilities, people who use prosthetics, people who are very tall, people who are very short, people who are very large,” said Denman, who also educates and advocates on behalf of people with disabilities. “Those kinds of vehicles work for lots of different people and are much more accommodating and make a park much more family friendly and inclusive because more people can ride and enjoy the ride together.”

“That, of course, is always possible,” Kupers said. However, he noted that many park clients prefer one size that fits most. “The challenge is to have one seat suitable and restraint suitable for a maximum of people.”

Industry changes

“The industry is pushing more and more toward trying to include more people,” Rocky Mountain Construction's Kilcup said. “That creates engineering challenges, but I think it's moving in a good direction.”

“It can't be in our interest to limit people (from) riding the rides when they could,” said Jakob Wahl, president and CEO of the International Association of Amusement Parks and Attractions.

Wahl noted that making rides inclusive is important for both ethical and business reasons. “I can guarantee you that this is an ongoing discussion within our group on how we can actually allow for a maximum of fun.”

Denman agrees, “Most theme parks do their best to be as inclusive as possible.” But she knows more can be done.

She encourages travelers to reach out to parks, “reply to their tweets, send them request letters, advocate for ourselves and ask for the things we need to be able to enjoy all the rides.”

This article originally appeared on USA TODAY: Most US adults are overweight. So why aren’t theme park rides bigger?