Study On The Safe Operating Speed And Speed Limit Of Freeway Curve Sections In Mountain Areas

Mountain Freeway curve sections are prone sections of highway accidents, the numberof curve accidents is not the highest proportion in the total number of accidents, but its seriousconsequences of the accident, could easily lead to a large loss of life and property. Of all kindsof the curve accidents, rollover accidents cover the highest incidence, especially in mountainhighway curve sections, heavy trucks rollover accidents occur more frequently. The reason forrollover accidents are, mostly for speeding in the dangerous sections. Therefore, reasonablespeed limit management is the key to reducing the accidents.In this paper, rollover accident speeding is taken as the research object, the main researchcontents including the relationship between mountain freeway curve vehicle speed andsecurity and speed safety system, designed to raise mountains highway road speed limit valuecurve developed method, based on the characteristics and environmental characteristics of theselected road traffic safety measures appropriate speed limit.The main contents of this paper include: Firstly, curve section vehicle driving stabilitymodeling and analysis, applying vehicle dynamics to build road and vehicle parameters-speedmodels. The models include both the ideal rigid car models and the models taken vehicleparameters into consideration. The stability of cars and trucks operating in the curve sectionsis analyzed after the modeling. Secondly, the speed limit reference value is determined by aseries of calculation methods based on the freeway speed limit theories. After that, manyspeed limiting secure measures are listed in the paper, from laws and regulations to the speedlimiting signs and markings and so on, covering almost all kinds of speed limiting measuresapplying nowadays.This innovation includes: Firstly, the current researches domestic and abroad both mainlystudied the circumstance of non-mountainous freeways, and less for the mountainous road.This paper take the characteristics of mountainous freeway traffic environment intoconsideration, mainly surround the speed and safety in the mountainous section of freeway,and that is the innovation of topic; Secondly, driving stability modeling in the past built themodel from only a single angle of sideslip or rollover, the results of the study are tooconservative, inconsistent with the actual situation. This study consider both rollover andsideslip and the relationship between the two kinds of dangerous states and vehicle operatingspeed before the accident, the research results could more conducive to guiding traffic safetyproduction practices; Finally, the models provide an upper limit in the form of quantitative forthe speed limiting of the mountain freeway curve sections, which could provide practical and theoretical basis for the development of mountain freeway curve section speed limit policy.