In this 1945 Mechanix Illustrated article, Harold S. Kahm sets out the facts for any would-be ride-designers looking to hit the jackpot with a new high-speed thrill. Starting with the origin story of the bumper car (a WWI munitions plant worker built a miniature truck for hauling parts, the plant workers went crazy riding it, so he covered it with bumpers and turned it into a carny ride), he moves onto the holy grail of 1945 amusement parks: a portable ride. The best thing about this article are the diagrams on the second and third pages. Woah. Charlie at the Modern Mechanix blog has them up at a generous 1800px wide, perfect for clip-art harvesting.
As a matter of fact, hundreds of new ideas for rides flow into the offices of ride manufacturers in a steady stream, but not one in a hundred is even worth consideration, simply because the average inventor has no understanding of the technical requirements of the industry; he doesn't, in fact, seem to know anything about anything—if you can believe the expert ride men. So if you think you'd like to try your luck in this fabulously successful field, which is certainly one of the best in the world for the amateur inventor, here are the facts you should know: The average successful ride is easily portable; it can be set up or dismantled in a few hours, and conveniently loaded into one or two trucks. If it is not portable, in this manner, it will be of no use to the richest and biggest ride market—the travelling carnival. A portable ride, on the other hand, is just as saleable to permanent amusement parks. In other words, you can sell a portable ride to any ride operator, but if it isn't portable your market is limited to parks alone.
If you can figure out a way to make permanent park rides portable—such as the roller coaster—you've got yourself a million dollars; every big carnival company in existence would buy one, and wouldn't hesitate to pay $50,000.00 for it. A coaster in a good location can make that much in a season. But on the other hand, just design a new and better type of coaster for parks and you'll do all right, too; $5,000.00 royalty per coaster is considered a reasonable payment, and there might be 200 park owners scrambling for the new design.