This paper outlines the preliminary results of a field evaluation of a prototype near infra-red Vision Enhancement System (VES) using a contact analogue Head-up Display (HUD) presentation. The evaluation compared speed, cognitive workload and reaction times for the detection of simulated pedestrians while driving a route with the operational VES and without the VES at night. Results indicated that VES operation necessitated greater mental demand and effort, and resulted in slower speeds (at least initially) as well as a generalised trend to greater speed variation over time. The results are discussed in terms of the functional qualities of the demonstrated VES prototype.