The pedestrian hybrid beacon (PHB)–or high-intensity activated crosswalk (HAWK), as it is known in Tucson, AZ– is a traffic control device used at pedestrian crossings that was first included in the 2009 Manual on Uniform Traffic Control Devices (MUTCD). The treatment typically has the crosswalk marked on only one of the major road approaches. The PHB’s vehicular display faces are generally located on mast arms over the major approaches to an intersection and in some locations on the roadside. An example is shown in figure 1 for an installation in Tucson, AZ. The face of the PHB consists of two red indications above a single yellow indication. It rests in a dark mode, but when it is activated by a pedestrian, it first displays to drivers a few seconds of flashing yellow followed by a steady yellow change interval and then displays a “walk” indication to pedestrians and a steady red indication to drivers, which creates a gap for pedestrians to cross the major roadway. During the flashing pedestrian clearance interval, the PHB displays an alternating flashing red indication to allow drivers to proceed after stopping if the pedestrians have cleared their half of the roadway, thereby reducing vehicle delays. Additional information about the PHB is available in the MUTCD. The PHB has shown great potential for improving pedestrian safety and driver yielding. However, questions remain regarding under what roadway conditions– such as crossing distance (i.e., number of lanes) and posted speed limit–should it be considered for use. In addition, there are questions about the device’s operations; for example, a current topic of discussion within the profession is the way drivers treat a PHB when it is dark. PHBs dwell in a dark mode for drivers until activated by a pedestrian. A concern within the profession is that drivers will see a dark PHB and treat it as a Stop sign (R1-1), similar to the required behavior for a dark traffic control signal that has experienced a power outage. Because of the questions being asked regarding driver and pedestrian behaviors with PHBs, the Federal Highway Administration (FHWA) sponsored a study to record behaviors at existing sites. This TechBrief describes the methodology and results from an open-road study that examined driver and pedestrian behavior at crosswalks with PHBs. The objective of the study was to determine actual driver and pedestrian behaviours at locations with a PHB. (Author/publisher)
Samenvatting