This research project aims at empirically analysing psychological effects of longer-term construction sites on German highways on traffic participants with regard to the length, design, and arrangement of work-zones. Despite previously conducted studies, the influences of work-zone lengths and succession on traffic participants have not been analysed sufficiently from both, traffic engineering and psychological perspective. The objective of this project is to measure the effects on various levels and in different contexts to derive recommendations for implementations in practice. The concept and conducting of the study as well as implementing attained results necessitate a solid foundation on traffic psychology as well as traffic engineering. Therefore an interdisciplinary approach, involving the cooperation with psychologists, sociologists and traffic engineers is indispensable for the analyses. The result of this research project is the realisation that certain rules for designing work-zones ought to be reconsidered. The results indicate that lengths of 15-20 kilometres are acceptable, provided that the lane width is sufficient. Only for work-zones exceeding this length the conducted investigations showed a tendency in car drivers to travel at higher speeds. One cannot generally state that a long work-zone is favourable over staggered work-zones. In this case no notable behavioural changes were observed. Merely the numerous deviations and changed traffic routings can be seen as mentally demanding characteristics. Thus, too many work-zones in close succession should be avoided. Furthermore, longer reassurance route between the staggered workzones may compensate a large proportion of aggression and frustration by repeatedly offering breaks from stressful driving within work-zones. According to the study's results speed limits should be implemented here as not to force the traffic participant to decelerate excessively before entering the next work-zone segment. In addition, long reassurance routes towards the end of a series of work-zones can harmonise the velocities and thereby stabilise the traffic flow. At all investigated simulation studies to reduce the speed before a work-zone, good compliance with the speed limit was observed. Merely information on the reason for a reduced speed limit should be made visible to traffic participants. In general, information on the construction progress and the current situation should be made available to traffic participants. This gives traffic participants a feeling of inclusion with regard to the processes in the work-zone leading to more positive perceptions thereof. A more relaxed driving experience in workzones is another result enforced by this state of mind. With regard to the possibility of changing the colour design of the median divider with the left demarcation of the auxiliary lane the simulation study resulted in the following finding: The colour design of the median divider tends to lead the traffic participant to use the left side to orientate him/herself rather than the right side. The test persons perceive the right lane to be more of a hazard than oncoming traffic on the other side of the dividing elements. Conclusions drawn from simulator studies must always be viewed critically and with much caution. All recommendations should be tested under real conditions and evaluated once more. (Author/publisher)
Abstract