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51 Type of work activity (e.g., construction or maintenance, 6. Other work zone non-crash accidents--While work zone permanent or temporary, specific activity, etc.); crashes involving traffic are a major safety concern for the Location of the crash in the work zone (e.g., advance warn- traveling public, workers are at risk both from traffic ing area, transition, etc.); crashes and from industrial accidents that occur in work Money spent on construction/maintenance projects; zones. These include falls, electrical contacts, struck by Duration of work zone; work vehicles/equipment, etc. Data elements needed for Total number of miles of work zone; such accidents are similar to those needed for work zone Number of work zones per type of roadway; crashes but involve industrial accidents rather than traffic Volume of traffic through the work zone; crashes. Worker injury data from industrial accidents may Hours of work zone activity without positive protection; be a major cost factor in highway programs, and its avail- Queue lengths per type of roadway; ability can be useful in the overall safety management of Running speed or other traffic operational measures about highway programs. the work zone; Frequency of motorists exceeding the posted speed limit; and Review of Work Zone Crash Data Number of erratic/conflict maneuvers in work zones. Sources and Systems A detailed list of data elements for work zone crashes is dis- The discussion above clearly establishes the importance of cussed at the end of this chapter. The most basic data com- access to detailed work zone crash data, and this importance ponents needed to address these objectives can be grouped is recognized by state highway agencies. It also establishes that into the following categories. there is little consistency among the systems used to compile work zone data and that the systems in use entail a range of 1. Basic crash characteristics--Information such as the basic shortcomings. There are a number of systems and approaches nature of the crash, location, time and date, vehicles and currently in use to record and compile work zone crash data persons involved, resulting injuries, and basic roadway on a statewide or national basis. The three most basic systems characteristics is included in sufficient detail in most state currently in use are described as follows. crash report forms. All of this information is critical in assessing crash causation and severity and is equally im- State Crash Reports portant for work zone crashes. 2. Work-zone-specific crash characteristics--The involvement In most states, crash reporting is coordinated by a central- of workers, work vehicles and equipment, and other work ized state agency, with the crash reports generated and sub- zone features is important to address various work zone mitted by police agencies and in some cases by the motorists objectives. involved in the crash. This system typically includes the use 3. Work zone characteristics--Information describing work of a state standard reporting form. Many state crash report- zone characteristics is critical to assess the effectiveness of ing forms and procedures currently in use do provide a way work zone procedures and to identify needed improve- to identify crashes occurring in work zones. However, in ments. Desirable information includes work zone type most cases, only very limited data elements are compiled con- (lane closure, crossovers, etc.), devices and safety features cerning the work zone and its involvement. Furthermore, present, location of devices and safety features, presence of there is little consistency in the forms and procedures used work operations/equipment/workers, when work activity between states, and even within states in some cases. was occurring (day, night, weekends, etc.), whether lanes Crash reports are used by a number of states to summarize were being closed, and other information to fully describe work zone crashes within the state. However, in most cases, the work zone at the location and time of the crash. the level of detail captured is limited, and in most cases it does 4. Basic project characteristics--This includes the project type not permit the examination of specific work zone parameters. (pavement overlay, reconstruction, widening, bridge re- Because of the state-to-state differences, it is difficult to com- pairs, etc.), length and duration of the project, project lim- bine data on a nationwide basis to address issues of national its (mainline and intersecting roads), project budget, etc. concern beyond very simple measures such as total work zone 5. Traffic operating characteristics--Several data elements are crash fatalities. needed to develop exposure rates and assess traffic opera- tions. These include traffic volumes, operating speeds, MMUCC Guideline-Based Enhancements speed limits, queues, delays, and travel times. These data to State Crash Reports elements are needed to establish crash rates and to stratify crashes during certain operating conditions of the work The Model Minimum Uniform Crash Criteria (MMUCC) zone (such as crashes during periods of queuing). guideline defines a dataset for describing crashes of motor