Notes for Figure 6H-37—Typical Application 37 Double Lane Closure on a Freeway
- 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.
- Ordinarily, the preferred position for the second arrow board is in the closed exterior lane at the upstream end of the second merging taper. However, the second arrow board should be placed in the closed interior lane at the downstream end of the second merging taper in the following situations:
- When a shadow vehicle is used in the interior closed lane, and the second arrow board is mounted on the shadow vehicle;
- If alignment or other conditions create any confusion as to which lane is closed by the second arrow board; and
- When the first arrow board is placed in the closed exterior lane at the downstream end of the first merging taper (the alternative position when the shoulder is narrow).
- All advance warning signs mounted on portable supports shall be equipped with at least two flags or a flashing warning beacon. Each flag shall be at least 16 X16 inches in size and shall be orange or red in color. Flashing warning beacons (Section 6F.83) shall be used to call attention to the initial warning signs during hours of darkness. Flashing warning beacons is optional during daytime operations.
- A truck-mounted attenuator may be used on the shadow vehicle.
- If a paved shoulder having a minimum width of 10 feet and sufficient strength is available, the left and adjacent interior lanes may be closed and vehicular traffic carried around the work space on the right-hand lane and a right-hand shoulder.
- When a shoulder lane is used that cannot adequately accommodate trucks, trucks should be directed to use the normal travel lanes.
- 3 cones or 2 Type II barricades shall be placed transversely across each closed lane at end of each merging taper and every 2000 feet throughout the lane closure.
- On freeways, maximum spacing of channelizing devices shall be 50 feet in advance warning and transition areas, 100 feet in activity and termination areas (see figure 6C1).
- LANE CLOSED C30(CA) sign should be placed every 2000 feet throughout the lane closure adjacent to the open lane within the closed lane.
- For State highways, see Department of Transportation’s Standard Plan T10. See Section 1A.11 for information regarding this publication.