Just a little add-on to Gary's post--These facilities are being placed at EVERY mainline turnout. We just finished a new spur track to the east of the Spokane Industrial Park with a direct mainline turnout. Since this was not "grandfathered" by prior existance, the industry was charged an additional $20,000 for the installation. At least in the Spokane-Eastport test area, each and every turnout has its own--even if there are 2 turnouts in very close proximity. This being "dark" territory, it appears that this equipment positively relays information about the switch point position to the "system", since there is a direct link from a connecting rod to an underground box.