Performance Test of Wireless Technologies for Personnel and Equipment Proximity Sensing in Work Zones

The dynamic nature and limited work space of roadway work zones contribute to dangerous working environments for construction workers. This environment can result in hazardous proximity situations because pedestrian workers are required to operate in close proximity to heavy construction equipment. A total of 609 work zone personnel fatalities were reported in 2012. Previous analysis of work zone fatality data found that the majority of the pedestrian worker and mobile object struck-by fatalities resulted when pedestrian workers were struck by construction equipment. These statistics indicate that current safety practices for pedestrian workers and equipment operators are inadequate. The objective of this study was to create and evaluate a proximity detection and alert system using Bluetooth sensing technology. The scope included hazardous proximity situations between pedestrian workers and construction equipment in roadway work zones at grade. Evaluation metrics were implemented to assess the tested proximity sensing systems including the cost, time and ease of calibration, required hardware, system capabilities, and many others. Commercially available radio frequency identification (RFID) and magnetic field proximity sensing systems were also evaluated to provide a basis for comparison. Various interaction scenarios between pedestrian workers and construction equipment were used in the evaluation of the system. The performance evaluation based on the statistical results showed that all the tested systems were considered reliable with minimal false alarm rates. However, the magnetic system showed a significant drop in its coverage range, while still providing reliable coverage measures, with a set of tests that were more dynamic than other sets of tests. The created Bluetooth system provided the highest level of simplicity with its minimized infrastructure, ease of calibration, and ease of installation. In sum, experimental results demonstrate that the created proximity detection and alert system (1) requires minimal infrastructure; (2) provides adequate alerts to equipment operators and pedestrian workers; and (3) provides, through an alert, an additional layer of hazard avoidance in real time during hazardous-proximity situations in roadway work zones.