In South Carolina, arrow panels supplementing TMAs in lane closures are required to operate in the “Four Corners” caution mode when advanced farther than 250 feet beyond the end of the taper.
When a TMA is placed deep into a lane closure, the “Four Corners” mode is required to avoid any confusion on the motorist’s part that they should change lanes as usually perceived by the “Flashing Arrow” mode.State/Agency: South Carolina
Where Documented: "Standard Drawings for Highway Construction" Drawing No. 605-4, 5, 6, & 7 and Drawing No. 605-9,10,11, & 12
Topics: Arrow Panels; Lane Closure