Notes for Figure 6H-35—Typical Application 35 Mobile Operation on a Multi-Lane Road
- Arrow boards shall, as a minimum, be Type B, with a size of 60 x 30 inches. For State highways, the arrow boards shall, as a minimum, be type II, with a size of 72 x 36 inch. Refer to Department of Transportation’s Standard Specifications Section 12-3.03 for minimum size and type of arrow panels cited above. See Section 1A.11 for information regarding this publication.
- Vehicle-mounted signs shall be mounted in a manner such that they are not obscured by equipment or supplies. Sign legends on vehicle-mounted signs shall be covered or turned from view when work is not in progress.
- Shadow and work vehicles shall display high-intensity rotating, flashing, oscillating, or strobe lights.
- An arrow board shall be used when a freeway lane is closed. When more than one freeway lane is closed, a separate arrow board shall be used for each closed lane.
- Vehicles used for these operations should be made highly visible with appropriate equipment, such as flags, signs, or arrow boards.
- Shadow Vehicle 1 should be equipped with an arrow board and truck-mounted attenuator.
- Shadow Vehicle 2 should be equipped with an arrow board. An appropriate lane closure sign should be placed on Shadow Vehicle 2 so as not to obscure the arrow board.
- Shadow Vehicle 2 should travel at a varying distance from the work operation so as to provide adequate sight distance for vehicular traffic approaching from the rear.
- The spacing between the work vehicles and the shadow vehicles, and between each shadow vehicle should be minimized to deter road users from driving in between.
- Work should normally be accomplished during off-peak hours.
- When the work vehicle occupies an interior lane (a lane other than the far right or far left) of a directional roadway having a right-hand shoulder 10 feet or more in width, Shadow Vehicle 2 should drive the right-hand shoulder with a sign indicating that work is taking place in the interior lane.
- A truck-mounted attenuator may be used on Shadow Vehicle 2.
- In high-speed roadways, a third shadow vehicle (not shown) may be used with Shadow Vehicle 1 in the closed lane, Shadow Vehicle 2 straddling the edge line, and Shadow Vehicle 3 on the shoulder.
- Where adequate shoulder width is not available, Shadow Vehicle 3 may also straddle the edge line.
- For state highways, see Department of Transportation’s Standard Plan T15 and T16. See Section 1A.11 for information regarding this publication.