user client to the location engine. A three-dimensional model of
the site, surrounding environments, and position of pre-defined
hazardous areas are stored VCS. The locations of the observed
objects (workers, equipment, and vehicles) are also translated
and visualized in real-time. Once the detected distances between
workers and their surrounding sources of danger are less than an
allowable safety value, warning signals are triggered and sent to
the real-time location engine, which then relays the signal to activate
the tag warning devices installed on the helmets. The end
users equipped with the e-tagging system can visualize all of the
unsafe location-based behaviors and safety report via an intuitive
graphical user interface in a remote web center, as is shown in
Fig. 2. The end users include safety officers, safety supervisors,
equipment operators, site workers, and system maintenance workers.
The e-tagging system (including data storage and retrieval) is
used to enhance the PCMS functions for the safety of the site end
users (Riaz et al., 2006). This e-tagging system provides a wireless
internal linking with the safety database and offers numerous
other benefits, including encoding worker e-tags with personal
information (e.g., user profile, role, tasks, and existing project conditions)
and safety performance (e.g., habitual unsafe behaviors,
accident records and past SI scores). Moreover, vehicle e-tags can
be encoded with maintenance information for equipment health
monitoring, thus generating automatic updates of vehicle maintenance
schedules and inspections