Imagine you're riding in a train, when you see another train hurtling toward you on the same track. No problem. You're on the "anti-collision train," designed by P.K. Stern of New York. It was a bold idea for improving travel safety, but it never caught on. The Strand magazine (1904) explained the concept:
A single track is used, on which railway-cars are caused to travel. Two cars are rushing towards each other at a speed of twenty-five miles an hour, so that a collision would, under ordinary conditions, be inevitable, when suddenly one of the cars runs, not into, but over the top of the other and lands on the track on the other side, where it continues in perfect safety to its destination. The underneath car has proceeded as if nothing had happened.
The cars, although they run upon wheels, are really travelling bridges, with overhanging compartments for the accommodation of passengers. Over the framed structure of the cars thus constituted an arched track is carried, securely fastened to the car and serving the purpose of providing a road-bed for the colliding car. This superimposed track is built in accordance with well-understood principles of bridge construction.
When I was very little, growing up in a small suburb of Charleston, South Carolina, one of the most exciting things to do was to sit outside the barber shop and wait for the train to roll through town. Some people might say that would be as boring as watching grass grow, but they are not "railfans". So what's a railfan? The people who camp out for hours, and even days, to watch a train go by. According to Train Magazine, there are over 175,000 railfans in the United States and more than 24,000 railfan videos on YouTube. Bill Taylor, from Montana, sums it up the best by saying "It's an orchestra of motion." Learn more about railfans here.