Types of Object Markers (Texas MUTCD, Section
2C.63
)

There are
four
 types of object markers as described below and illustrated in Figure 8-1.
  • Type 1 Object Marker:
     A yellow diamond-shaped panel consisting of all retroreflective sheeting (OM1-3).
    • The minimum size of the OM-1 is 18 x 18 inches.
    • The bottom of a Type 1 object marker
      should be 4 ft above the edge of the travel lane and is mounted on thin-walled tubing
      .
  • Type 2 Object Marker:
     A yellow rectangle or series of three yellow reflectors.
    • OM2-X: A series of three yellow retroreflectors.
      The minimum size of each retroreflector is 4 x 4 inches. OM-2X is mounted on wing channel post.
    • OM2-Y: A yellow rectangular panel consisting of all retroreflective sheeting. The minimum size of the panel is 6 x 12 inches.
      OM-2Y is mounted on wing channel post.
    • OM2-Z: A series of three yellow retroreflectors or a single larger yellow retroreflector. The minimum size of each retroreflector is 3 x 4 inches when used in a series of three. For a single retroreflector, the minimum size is 3 x 12 inches. OM2-Z is mounted on a flexible post.
    • The Type 2 object marker is
      usually
       mounted with a vertical orientation.
    • The bottom of a Type 2 object marker is mounted at a height of
      approximately
       4 ft. If the object marker is within 8 ft of the edge of pavement, the mounting height is above the edge of the travel lane. When the object marker is more than 8 ft from the edge of pavement, the mounting height is above the ground. Higher or lower mounting heights can be used according to need.
  • Type 3 Object Marker:
    A vertical rectangle with black and yellow diagonal stripes.
    • OM-3L: An object marker with diagonal stripes oriented from the top left to lower right. The OM-3L is located on the left side of the road.
    • OM-3C: An object marker with diagonal stripes oriented from the center downward to the left and right. The OM-3C is located in the roadway when vehicles can pass on both sides of the object marker.
    • OM-3R: An object marker with diagonal stripes oriented from the top right to lower left. The OM-3R is located on the right side of the road.
    • All versions of the Type 3 object marker have a minimum size of 12 x 36 inches
      and are mounted on thin-walled tubing
      .
    • The bottom of a Type 3 object marker is located at
      approximately
       4 ft above the edge of the travel lane.
  • Type 4 Object Marker:
    A red diamond-shaped panel consisting of all retroreflective sheeting (OM4-3).
    • The minimum size of OM-4 is 18 x 18 inches.
    • Type 4 object markers are used to mark the end of a roadway, and are usually combined with a barricade (see Texas MUTCD Section 2C.66).
    • When ground mounted, OM-4 is mounted on thin-walled tubing 4 ft above the near edge of the traveled way.
Object Markers (click in image to see full-size image)
Figure 8-1. Object Markers