The Influence Of Highway Billboards On Driving Safety

Objective: The study is to investigate the influence of highway billboards on driving safety,respectively in different specifications, density and positions.Method: Subjects with driving licenses were selected to drive on the QJ-3B1 s imulator and were asked to memorize the billboards. All parameters were recorded on the simulator when manipulating vehicle and eye-movement index were recorded on the Smart Eye while looking at billboards. There are four experiments, The independent variables are the different s izes(big, medium, small), different density(none, lower, higher), and different positions in turning lanes(forepart, middle, afterpart); the dependent variables are driving parameters(driving speed, car-following distance, lateral deviations) and eye movement data(viewed times, total fixation time and the longest gaze). 3×2within subjects design for every experiment. Thirty subjects who have driving licenses were selected to each experiment, and their tasks were to follow the front car and pay attention to the billboards on roadside.Results: With attention to the billboards of different sizes when following car, the results for experiment 1 showed that there were significant differences in lateral deviations and the eye movement data(p<0.05), but there were no significant differences in driving speed and car-following distance(p>0.05). Compared with the straight lanes, the turning lanes were greater in car-following distance and lateral deviations(p<0.05) and were less in other dependent variables(p<0.05).With attention to the billboards of different density when following car, the results for experiment 2 showed that whether turning lanes or straight lanes, there were significant differences in car-following distance, lateral deviations, viewed times and total fixation time(p<0.05), but there was no significant differences in driving speed and the longest gaze(p>0.05).With attention to the billboards of different positions when following car in turning lanes, the results for experiment 3 showed that there was significant differences in all dependent variables(p<0.05). Compared with the right-hand turning lanes, the left-hand turning lanes were greater in lateral deviations, total fixation time and the longest gaze(p<0.05) and were equal in other dependent variables(p>0.05).With attention to the billboards of different positions(in the left-s ide of the road) when following car in turning lanes, the results for experiment 4 showed that there were significant differences in all dependent variables(p<0.05), except the longest gaze(p>0.05). Compared with the right-hand turning lanes, the left-hand turning lanes were greater in lateral deviations(p<0.05)and were less in viewed times(p < 0.05), there was no significant differences in other dependent variables(p>0.05).Conclusions: The billboards along the highway have effects on driving safety, the following facts are shown:(1) Effects of different specifications of the billboards on driving behavior are influenced by the type of the road, the turning lanes are greater than the straight lanes; the driver's eye movement behavior are influenced by specifications of the billboards, there are more viewed times and longer total fixation time to the big billboards, less impact on driving behavior.(2) Effects of different intens ity of the billboards on driving behavior are influenced by the type of the road. In turning lanes, the lateral deviations of vehicle are greater, the car-following distance is shorter when the billboards are more than no and less, but there is no significant differences in driving speed;In straight lane with no billboards, the car-following distance is greater, the lateral deviations of vehicle are shorter,there are no significant differences in the less or more billboards, and there is no significant differences in driving speed. Different type of roads have effects on driving behavior, the turning lanes have greater effects. Compared with the straight lanes, the turning lanes have less effects on driving speed, greater effects on car-following distance and lateral deviations.(3) No matter billboards of the road on the right-s ide or left-s ide, the right-hand turning lanes have less effect; the billboards in the middle of the turning lanes have the largest effects on driving safety, whereas in the forepart of the turning lanes have the least effects.