Advisory in Canada is a yellow sign the actual speed limit in the area is 40 where the change occurs is not readily apparent due to the nature of the area as a truck inspection station. You leave a highway into a 40 zone and many trucking complice software handle this transition badly because of the way OSM handles off ramps. Trucks traveling by almost always get put on the 40 off ramp and tagged for speeding also moving from highway speed to 40 creates compliance issues. So I made all of the rest area highway speed because I have attempted. Moving lanes slightly but due to close proximity to the highway it still flags in most truck compliance software as speeding. So I used the advised tag so that when you approach this zone only for trucks the software will advise that you go 40 but will not ding you for complice issues in most trucking safety software.