Abstract:By comparing the specifications of highway and urban road, combined with the common poor situations of sight distance, the difference of sight distance between highway and urban road is analyzed. The study result shows that the theoretical basis of the car stopping sight distance between highway and urban road is basically the same, and only the calculation values are different. Each of these differences has its advantages and disadvantages, and is unreasonable and prone to contradictions, which often make the designers hard to choose, but can be unified. The entrances and exits are the road sections with a high proportion of accidents. It is necessary to ensure the recognition of sight distance, which should be supplemented in the urban road specifications. Aiming at the low design speed, small traffic flow, and the non-light-controlled intersections with the priority traffic management on the main roads, the safe cross-stopping sight distance can not only meet the regulations on the sight distance, but also reduce the engineering quantity of removing the obstacles in the trigonometric area of sight distance so as to save the engineering cost. The piers of urban road viaducts should be arranged reasonably, the shrubs should not be planted in the side zonings, the radius of the vertical curve should be as large as possible, and the limit value should be avoided to ensure the sight distance and the driving comfort. The solar energy active luminous signs can be used to promote in order to meet the needs of night driving sight distance with the anti-glare, and to reduce safety hazards.
