Validate First; Simulate Later: A New Approach Used at the FHWA Highway Driving Simulator

For several years the Federal Highway Administration (FHWA) Turner Fairbank Highway Research Center (TFHRC) has been conducting a research program on the effectiveness of roadway delineation for providing enhanced guidance to the driver negotiating curves on rural two-lane roads at night. The FHWA Highway Driving Simulator (HDS), located at the TFHRC, plays an important role in this research program. However, the results of such simulator research must be periodically validated by field testing in a more natural environment. For the first series of studies in this research program substantial simulator experiments were conducted first employing simplified roadway scenarios, and a modest field validation experiment was conducted later. Subsequent experiments represent a paradigm shift. The validation of simulator experiments employing more complex roadway scenarios requires finding a real rural two-lane roadway with a number of different curves in each direction. It is much easier to find such a natural roadway first and then simulate it later, than it is to devise a simulator scenario and then try to find a natural roadway which corresponds in most significant ways. Several advantages were realized from conducting the field experiment first. Most of these advantages derive from working with the intimate details of the real situation first and then identifying and transferring relevant aspects to the simulation. This paper describes some of these advantages and reveals some lessons learned.