an interval during which the WALKING PERSON (symbolizing WALK) signal indication is displayed.

a beacon used only to supplement an appropriate warning or regulatory sign or marker.

a portable, powered, yellow, lens-directed, enclosed light that is used in a temporary traffic control zone in either a steady burn or a flashing mode.

a sign that gives notice to road users of a situation that might not be readily apparent.

a warrant describes a threshold condition based upon average or normal conditions that, if found to be satisfied as part of an engineering study, shall result in analysis of other traffic conditions or factors to determine whether a traffic control device or other improvement is justified. Warrants are not a substitute for engineering judgment. The fact that a warrant for a particular traffic control device is met is not conclusive justification for the installation of the device.

the signals, switches, and/or control devices for railroad or light rail transit operations housed within one or more enclosures located along the railroad or light rail transit right-of-way and/or on railroad or light rail transit property.

a stationary horn (or series of horns) located at a grade crossing that is used in conjunction with train-activated or light rail transit-activated warning systems to provide audible warning of approaching rail traffic to road users on the highway or pathway approaches to a grade crossing, either as a supplement or alternative to the sounding of a locomotive horn.

The start of work activity in or along the road.

That portion of the work zone which contains the work activity, equipment, materials and workers.

Any vehicle in the work area or work zone (mobile operations) conducting work. Examples include sweepers, rollers, paver, striping truck, one-ton utility truck, and supervisor’s pickup truck.