The effectiveness of visual clarity is driven by an optimized combination of flash rate, light volume, color and intensity.
Virginia Tech Transportation Institute (VTTI) applies cutting-edge scientific methods to design, refine and evaluate solutions to complex transportation challenges. The organization supports automakers, automotive suppliers and policymakers to assess and improve the effectiveness of safety systems by quantifying performance benefits, resilience and unintended consequences.
VTTI Phase 1 Study (2021) – Assessed dozens of highly conspicuous lighting combinations to establish an optimal range of flash attributes.
The study found:
4Hz to 6Hz flash frequencies are significantly more attention-grabbing and communicate a more appropriate sense of urgency than standard hazard flashers.
This frequency range is the “sweet spot” for balancing urgent communications against discomfort and annoyance.
VTTI Phase 2 On-road Study (spring 2022) – Examined oncoming driver response to a disabled vehicle with hazard lamps flashing at 5Hz versus the standard hazard flash rate.
Significant driver response to H.E.L.P.TM Lighting Alerts included:
Drivers Slow Down – Oncoming drivers decelerated at a greater rate and at a substantially further distance away than drivers approaching the same test vehicle with normal hazard lights.
Drivers Move Over – Oncoming drivers changed lanes, typically moving a full lane away from the “disabled” test vehicle at observed distances of up to 360 meters, or nearly four football fields away.
Drivers Respond Earlier – Most approaching drivers decelerated and moved over a lane before crossing the farthest observation checkpoint of 360 meters, which translated to more than 12 seconds of observed advance warning / reaction time.
Dozens of empirical Human Factors studies conclude that driver perception improves with higher emergency hazard light flash rates. For example, a recent study at the Virginia Tech Transportation Institute (VTTI) found that higher-frequency flash rates dramatically increase perception of urgency.
The graph displays flash frequency against three dimensions of visual clarity – discomfort glare, annoyance and urgency. This finding is reinforced by studies conducted by NASA’s Ames Research Center.
In addition to providing a long-range visible beacon to oncoming drivers, ESS H.E.L.P. also deploys a digital signal upon activation of the hazard lights.
That signal is detected by emergency information systems and retail navigation applications, alerting all other drivers who are running a navigation application that there is a hazard ahead.
This visual and digital alert system provides drivers with plenty of advanced warning to avoid disabled vehicles on the road ahead, and will safeguard the lives of those in the disabled vehicles.