Michigan DOT’s current practice is to delineate the temporary concrete barrier (TCB) with barrier markers placed at 6m max spacing at a height of 460 + 25mm from the bottom of the barrier marker to the top of the marker. MDOT also employs, as added delineation, the use of a painted or taped edgeline when the distance from the edge of the traveled lane to the TCB is .6m or greater.
MDOT is also using (sparingly) an aluminum panel, mounted to the top of the TCB, to provide delineation and to act as a glare screen in areas where there is sharp headlight angularity, i.e., entrance ramps or horizontal curves.
These aluminum panels are 12″ x 24″ and fabricated utilizing engineering grade sheeting. The sign face is laid out similar to an object marker (OM-3). The panels are attached, utilizing 2-3/8″ bolts, to a 1″ x 1″ x 12″ angle iron, which is then bolted to the top of the TCB with 2-3/8″ studs at 5 foot minimum spacing.
Assessment:
They currently use temporary barrier markers, by themselves, on the TCB for delineation. This type of static delineation is relatively new to the department since the elimination of the Type C lights on TCB a few years ago. The temporary barrier markers
State/Agency: MichiganTopics: Delineators; Temporary Concrete Barriers