Prominent Elements Of Road Design Of The Driver's Psychological Expectations

The problem of road traffic safety is a significant problem. It has been being highly valued by some interrelated departments. However, the research into road traffic safety can not be finished independently in one subject or field alone, it comes down to the subjects of highway engineering, traffic_ psychology, etc. Presently, the research into traffic_ psychology mode has changed from the"driver to road traffic accident"into"road design to driver to road traffic accident".Driving expectation means that in the course of driving information disposal, driver conjectures the dynamic road environment on the basis of road traffic condition, and then give birth to a expectant plan which is aimed at the following driving behavior. If the road design gives attention to the driving expectation, the threshold which brings"information_deviation"will rise, and the range of "information_deviation"will fall. Then, the driving stability become better and more safer. The driving expectation is the transmission shaft which makes the road environment and the driving behavior interact. The road environment affects drivers by driving expectation."self-explaining"is a important factor in road design. itmeans the standard of road design accords with the standard of drivers 'expectation. Furthermore, it means drivers'subjective road classification accords with the official road classification, and their expected driving speeds accord with the designed speeds. A good"self-explaining"road is a pleasing and safe road. Otherwise, there will be hidden traffic troubles.For drivers, long_time driving expectation forms at the early stage of driving assignment. In the course of the formation of the long_ time driving expectation, several discriminative features of design elements (DFDE)are very important to the formation of expectation. The DFDE trigger drivers' expectation towards the given road and result in the corresponding behavior and make driving behavior reaches high roboticized standard. At present time, the research into the DFDE needs deepening. In this research , the special software of highway field named HARD2000 are used. According to the road linear design criterion of ministry of communications, five standard roads are designed as the Determined main_ roads. Accordingly, also sub_ roads are designed with the model of the main roads. Both of the main_ roads and the sub_ roads have the same grade and Determined speed, but there is a different road element between them. In every three-dimensional cartoon of the road, ten seconds video is intercepted and saved as video document with the suffixal name of "avi". The video documents are used as experiment datum in the system of "DFDE stimulate_reaction". 1. In the compare of drivers' subjective road classification and official road classification, descriptive statistical method is used. Approximately, the result coincides that of overseas. The fact that drivers 'subjective road classification do not completely coincide with official road classification means domestic road "self-explaining"is not good.2.Drivers'expected driving speeds and that of official design are also compared and analyzed, but the coherence is even worse. The result indicates drivers' expected speeds are more rapid than standard speed at large.3.The aim to give the subjective road classification and the expected speeds a "t test"is used to find out DFDE which are responsible for the change of driving expectation. The experiment result indicates that road surface, surface sign, integral color of the road environment, bad tortuous slope group and defending fence are DFDE. They can stimulate drivers' expectation and arose corresponding behavior and then makes driving behavior reach a high automized standard.So, in the road design in future, we should pay attention to these road elements to benefit the formation of drivers' exact expectation. To the built road sections which are prone to traffic accidents, some measures should be taken to adjust DEDF to benefit the formation of drivers'exact expectation and to prove traffic safety.