TC-1 must be used to provide advance warning of a work zone for long duration operations and may be used for a short duration work zone. In rural areas, a TC-1A sign must be added at a distance of 1 km in advance of the work zone. For freeways, TC-1A and TC-1B signs must be installed at distances of 1 km and 2 km from the work zone, respectively. TC-101 must be used on roadways with more than two lanes, and posted limits of 70 km/h or higher.