Study On The Connection’s Key Technical Indicators Of Highway Interchange

The interchange is the highway`s critical parts, that typically uses grade separation,ramps, to permit traffic on at least one highway to pass through the junction without directlycrossing any other traffic stream. Although the proportion of its ramps`length is relativelysmall to the highway, the interchange often has a high probability of traffic accident due to itscomplex, more forks and also the big difference in the speed between the interchange and thehighway mainline. On the one hand, our country`s specified value of the distance between thecontinuous forks was refer to some developed countries, such as Japan and American. Onanother hand, the provisions of the value lack the consideration of the actual vehicle speedcharacteristics and the provision in this regard is not a comprehensive one.In the use of collection from the research results at home and abroad, as well asinterchange`s current status indicators, analyzing accident related to the design specifications,analyzing the problems of the provisions indexes and actual traffic survey, especially on acontinuous traffic flow characteristics were observed between each combination of differenttypes of continuous ramp-pairs, and summed up the impact factors which influence thedistance between the entrance and exit, using the changing line model and the signrecognition distance model, combing the observed traffic flow characteristics of differenttypes of ramp-pairs to calculate the spacing value, and gives the recommended value.According to the analysis of the resulting interchange combination problems, andthrough field investigation and theoretical analysis, vehicle speed, driving expectations, therelationship between the driver’s heart physiological characteristics and interchange linearindicators, propose realistic and humane key technical indicators of the interchange. Using ofthe exit point of the interchange`s observed characteristics of the vehicle running speed,combined with heart rate characteristics of the driver, and gradual deceleration lane forgradual rate before the segment, curve radius near the split nose, the length of the verticalcurve radius and transitional segments, etc. parameters were studied, and propose thecalculation value.