PATA 009
Trailer-Mounted Equipment Placement

  1. Clear Zone width is shown on the table below. See Publication 13M, Design Manual Part 2, Chapter 12, for more information about Clear Zones.
  2. Delineation is required for trailer-mounted equipment located within the clear zone, except when protected by barrier. Cones may be used if the trailer will remain in place for less than 24 hours. Drums, vertical panels or other devices authorized for long term operations shall be used when the trailer will be in place for more than 24 hours. Drums are preferred because they are highly visible, have good target value, give the appearance of being formidable obstacles and, therefore, command the respect of road users. Also, drums are generally used in situations where they will remain in place for a prolonged period of time.
  3. Place trailers in the safest location that will provide maximum performance. The trailer hitch shall be on the opposite side of traffic approaching in the nearest lane as shown on the drawings.
  4. Placement and delineation requirements apply to all trailer-mounted equipment such as Portable Changeable Message Signs (PCMS), Speed Display Trailers, Portable Cameras, etc.
  5. PCMS shown on drawings; applicable to all trailer-mounted equipment.
Clear Zone Width
(In feet from edge of through traveled way)
Design Speed Design ADT Foreslope Backslope
    1V:6H or Flatter 1V:5H or Steeper 1V:3H 1V:5H to 1V:4H 1V:6H or Flatter
40 MPH or less <750

150-1500

1500-6000

>6000
7 7 7 7 7
10 12 10 10 10
12 14 12 12 12
14 16 14 14 14
45-50 MPH <750

150-1500

1500-6000

>6000
10 12 8 8 10
14 16 10 12 14
16 20 12 14 16
20 24 14 18 20
55MPH <750

150-1500

1500-6000

>6000
12 14 8 10 10
16 20 10 14 16
20 24 14 16 20
22 26 16 20 22
60MPH <750

150-1500

1500-6000

>6000
16 20 10 12 14
20 26 12 16 20
26 30 14 18 24
30 30 20 24 26
65-70 MPH <750

150-1500

1500-6000

>6000
18 20 10 14 14
24 28 12 18 20
28 30 16 22 26
30 30 22 26 28
Most Preferred
Trailer Placed Behind Existing Barrier or Outside Clear Zone
Where Existing Barrier Is Not Available
Delineation Not Required
Where Barrier Is Not Available
Trailer Placed off Shoulder, But Within Clear Zone
Delineation Is Required
Least Prefered
Trailer Placed on Shoulder
Delineation Is Required
Delineation Layout Detail for Trailer Placed Within The Clear Zone