I was doing the "Whole Day of Cane Creek" scenario, "Thompson to Potash" Stopped at Seven Mile to check out some small green pyramid things at the side of the track. Walked up to one of them & was instantly transported into "Canyon Explorer" scenario. What is the story with them ?
A glowing mark coming out the ground? These are markers for tutorials and scenarios that can be started from within the game. They're located close to where those activities start. The same style marker is used to show stopping points and objective markers en-route. They can all be turned off. The scenario markers won't activate unless you press the button associated with them. It comes up at the bottom of the screen telling you which scenario you can jump to.
"Instantly transported?" I'm pretty sure that it's necessary to click on one of these "pylons" (DTG terminology) in order to switch to it's activity and that a written description of the activity appears. This isn't Alice in Wonderland, after all.