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1 The objective of NCHRP Project 20-05 Topic 49-04 was to synthesize the current state of practice on the selection and setup of very short duration work zones (VSDWZs) where the traffic control setup may take longer than the actual work activities. The researchers sought to identify current practices in each state. The study method included a literature review and survey to glean information on VSDWZ practices. The survey request was sent to members of the TRB Standing Committee on Maintenance (SCOM). Forty-one agencies (82%) participated in the survey. The survey showed that only three states had a formal VSDWZ policy in place. Although most agencies do not use the term âvery short duration work zoneâ in their official docu- ments, they do recognize the need to perform very short duration work activities as part of their maintenance programs. Eight agencies provide a list of factors to consider and allow the workers to make their own decisions about how to best perform the work activity. Ten agencies encourage the use of a spotter or lookout when performing quick maintenance activities. A few states use guidance language to allow exceptions to their lane closure policy. Some states provide decision-making support by way of â¢ Tables for temporary traffic control (TTC) selection by work activity (four states). â¢ Typical application (TA) drawings for specific very short duration (VSD) activities (two states). â¢ Guidance for specific very short duration (VSD) activities (three states). â¢ A flowchart for TTC selection (two states). The most commonly cited conditions that are considered hazards to proper TTC selection include â¢ Impaired/inattentive drivers. â¢ High traffic volumes. â¢ Inadequate sight distance. â¢ Worker inability to properly assess risk. â¢ Disobedient/impatient drivers. â¢ Speeding. â¢ Worker inability to properly estimate work duration. Due to the amount of time and effort required to set up a full lane closure, a full array of TTC devices is difficult to justify from the perspective of worker safety. To balance the use of TTC strategies using fewer devices, some agencies may use innovative equipment to reduce worker exposure or enhance the visibility of the workers or the work operation S U M M A R Y Very Short Duration Work Zone Safety for Maintenance and Other Activities
2 Very Short Duration Work Zone Safety for Maintenance and Other Activities itself. New technologies that agencies are using to reduce worker exposure during quick maintenance operations include â¢ Automated debris removal (vacuums, scoops, rakes, and plows). â¢ Pothole spray-patching trucks. â¢ Unmanned aerial vehicles (UAVs) for inspection jobs. In addition to the widespread use of high-intensity lighting packages on work vehicles, some states use law enforcement to increase the visibility of workers or the work operation itself when performing VSD activities. Eight agencies have experienced crashes or near misses during VSDWZ operations. Many of those agencies have changed their approach to VSD activities in an attempt to prevent those events from reoccurring. However, only one state provides workers with formal training on VSDWZs. Given the different approaches in use across the nation for selecting VSDWZ TTC, it is suggested that future VSDWZ studies focus on establishing a more systematic method of selecting the appropriate TTC for VSD work activities that can be used by all agencies. This may include an in-depth examination of the existing approaches (including the original reasons for taking that particular approach), development and evaluation of the effectiveness of VSDWZ TAs, and/or establishment of thresholds for when each TA is appropriate.