Survey of Snowplow Operators About Forward Lighting and Visibility During Nighttime Operations

Abstract

Snowplow operators are a valuable source of information about improving forward visibility at night in snow, fog, or rain. These men and women have a heightened awareness of forward lighting and associated visibility issues and will try various techniques to improve their ability to see. Consequently, these operators have first-hand empirical knowledge about the factors that affect forward visibility. The purpose of this study was to survey a large number of active snowplow operators to determine what issues they believed were most important for forward visibility in perturbed atmospheric conditions at night. A survey was distributed to 300 New York State Department of Transportation snowplow operators throughout New York. Respondents reported that the most effective solution was to place lamps with narrow-beam distributions, what they generally term “spot lamps,” away from the driver’s line of sight. They also reveal some apparently sound, practical observations that also should be considered for improving visibility, especially windscreen and wiper-blade designs. Of special interest too, some believe that the spectral composition of the forward lighting system should be considered. These observations led the authors to speculate on the reasons why operators were so supportive of yellow or amber lights. The results presented here are largely consistent with a similar survey performed by the Minnesota Department of Transportation.