Speeding was preceded by fewer speedometer glances, indicating the speeding was linked to participants’ momentary inattention to their speed control. The system did not significantly change the speedometer monitoring. Resultsĭrivers sped less with the warning system. Their glances to the speedometer and speed warning system’s display were recorded with an eye tracker. Nineteen participants drove in a driving simulator, either with or without a speed warning system implemented on a smartphone, which alerted them if they exceeded the set speed limit. With a speed warning system, drivers may pay more attention to the exact speed, which would be expected to increase glances to the speedometer. The study investigated how a speed warning system influence drivers’ speedometer monitoring, and how drivers respond when they receive a speed warning.