In this research project, the innovative 'hands-on' method, first developed by Walton and Thomas in 2005, was tested in its ability to evaluate the effects of improved road delineation on driver behaviour. The method uses hand positions on the steering wheel as an indicator of drivers' perceived risk, with drivers being more likely to place both their hands on the top half of the steering wheel when driving through a more difficult environment.
Specialist night-vision equipment and infrared floodlights were used to observe a total sample of 2896 drivers at three sites in the Greater Wellington region in 2009-2010. Other intermediate measures of perceived risk (speed and headway acceptance) were also recorded, in order to assess how drivers' risk perceptions changed with variation in the driving conditions (daytime/night-time, wet/dry) and road delineation (faded/upgraded roadmarkings).
The results showed that the 'hands-on' method was an effective and reliable tool to measure the impact of improved linemarkings on drivers, and to quantify the size of this effect compared with daylight driving. The method was sensitive to subtle changes in the road context, which makes it a useful instrument for road engineers to evaluate the relative improvement or change in drivers' responses to changes in road contexts.