Notwithstanding I posted the address of a site that deals directly with the easement thing, AND provided details on a jig to employ, I must say:
Do your roads run more smoothly today than years ago, before formulae with two or three variables was introduced!
Even *For Real Roads* squeal and shudder in turns that have been shot, laid out and bent with the most sophisticated powerful machinery known.
The simplest and best solution to a problem that has grown up and is now eating it's young, is to use that horrible flex track for all curves.
Even if you soldered twenty lengths of flex together, you will have to deal with the same length of too long sliding track for any given radius.
It does not matter a whit whether the radius is 24 inch on a 4x8 or 30 feet on a 15,000 square foot club layout, curve must meet straight.
Template drawings are created with precise and accurate CAD, but at some point you gotta nail some track down and at some point your radii must transition to a straight line.
I don't care how many MRR articles have been penned or how much mumbo jumbo is cast about, you're gonna hafta eyeball it and test run, test run and test run.
When a comet is caught by the gravitational pull of a planet or star it is flung into space at a tangent and continues on a course that descibes a hyperbole. The gravitational pull of the star or planet affects the course of the comet which would, if there were no gravitational effect, move away in a straight line.
This easement thing replicates that phenomenon.
For every unit of forward movement of the comet, there is a formula to determine the radius of the arc, the radius' center point in space and the length of the arc the comet has travelled or will travel through. It's a mathematical deck of cards, a real ice breaker at cocktail parties, but that's how the spaced out guys plunk the shuttles down.
In most, if not all derailment and coach or car swing out problems on curves, the culprit is too much car or coach extending beyond the center point of the trucks. The reason logs on the truck in front of you swing into your lane is because the center line of the axles under the logs is 30 feet from the end of the logs, not because the road builders didn't know about easements.
Now we can close this thread and put the dead horse icon on it.