<p>This paper presents the results of a research project aimed at providing insights into the human factors associated with nighttime work zones on the New Jersey Department of Transportation construction and maintenance projects. It examines the impacts that nighttime construction activity has upon the workers, from their perspective. These impacts were assessed through field surveys and interviews that included: highway engineers, construction workers, field supervisors, and contractors. The research methodology is briefly discussed. Field data from these interviews are analyzed for human factors such as sleep deprivation, eating habits, commuting difficulties and social/domestic issues. This research found evidence of long working hours, social and family disruption, long commutes and sleep deprivation. Most of the workers interviewed agreed that nighttime work has: (a) a negative impact on their body rhythms; and (b) a negative reaction impact on their social and family life. They were also agreements with their statements that their families react negatively to them due to working at night.</p>