Use and Worker Perceptions of Wearable Lighted Apparel

In 2023, fatalities that involved workers on foot being struck by a vehicle accounted for 60% of all fatal highway worker injuries (National Work Zone Safety Information Clearinghouse, n.d.). Increasing the visibility of road workers to oncoming drivers may help reduce this crash risk. Wearable lighted apparel has the potential to increase the visibility of road workers, but its impact on visibility and any potential drawbacks are not well understood. Additionally, regulations and codes governing safety apparel and the use of lights within work zones do not specifically address personal lighted apparel, so it is unclear how it fits within current standards. This study sought to fill these gaps in knowledge. First, a market review was conducted to determine the range of lighted apparel options currently available. Second, a review of legal and regulatory barriers was conducted to determine what types of lighted apparel may be allowed under current standards. Third, a closed-course human factors study was conducted to gather both objective and subjective measures of worker visibility using a variety of lighted apparel options. Fourth, a field study was conducted to gather user feedback from road workers who used various lighted apparel devices.

Fourteen different lighted apparel ensembles (including one no-lighting baseline ensemble) were selected for inclusion in the closed-course testing. The ensembles utilized three distinct lighted apparel devices (a lighted vest, a helmet light, and a shoulder-mounted light) in various configurations so that the impact of various aspects of lighted apparel could be tested. These included the lighting design (where the light was located on the worker), the light color (amber, green, red, or white), the flash pattern (flashing or steady-on), and intensity (high or low). Closed-course testing was conducted on the Virginia Smart Roads Highway test track. Three simulated work zones of varying complexity were set up. Within each work zone, an experimenter acting as a worker wore one of the selected ensembles. Participants drove an experimental vehicle along the test track and verbally indicated when they could first detect a worker in a work zone. The detection distance was measured using the differential GPS coordinates of the vehicle at the time of detection. Participants drove 15 laps to ensure that they saw each ensemble within each work zone. Results indicated that a combination of lights on the torso and lights on the head significantly improved detection distance in medium- and high-complexity work zones when compared to the standard retroreflective safety apparel. Green lights significantly improved detection distance across all conditions. Steady-on lights performed significantly better than flashing lights in the high-complexity work zone, but no difference was found in low- and medium-complexity work zones. No consistent effect of intensity was found.

The field study equipped Virginia Department of Transportation and contractor personnel with a subset of five ensembles for use in their daily activities. Feedback was gathered through surveys and a focus group discussion. Users agreed that green was the most effective color. Users also tended to prefer the helmet-mounted lights over torso or shoulder-mounted lights. Users indicated a desire for more flashing options. Based on the results of this study, the research team recommends using a green, steady-on, helmet-mounted light to increase the visibility of road workers.