Research On The Length Of Speed-change Lane And Minimum Net Distance Between Interchanges On Muti-lane Expressway

In recent years, to meet the needs of social development and traffic operations, thedomestic expressways have been completed or are about to carry out large-scalereconstruction and extension，thus multi-lane expressway will be the trend of expresswaydevelopment in the future. Interchange is an indispensable part of the multi-lane expressway，which has played the role of converting the traffic flow efficiently. With the improvement ofthe national expressway network and the regional road network,“small spacing interchangegroup” is gradually increasing, and the traffic accident of speed-change lane is trending toascent in the interchange area. How to make a multi-lane highway to play efficient and safeservice function is becoming an important research topic in the field of transportation.By analyzing the main influencing factors of the acceleration and deceleration lanelength, based on the headway distribution model of a certain service level, the calculationmodel of triple-phase acceleration lane length is established, which includes acceleration,waitting for gap, afflux. Based on secondary reduction theory, the calculation model oftriple-phase deceleration lane length is established, which includes constant speed, the firstdeceleration, the second deceleration. At the same time, through the combination ofexperimental investigations and related research, the parameters of calculation model forspeed-change lane are analyzed in detail. The recommended values of speed-change lengthand related parameters are deduced.According to traffic operation characteristics and lane changing maneuvers, combiningwith the export notice signs and considering the worst driving conditions, the gap acceptancetheory and kinematics are employed to establish the length of lane change operation betweeninterchanges with probability theory. To operating speed as the premise, the necessary lengththat drivers change to the inside lane from the nearside lane is analyzed in terms of waiting forthe gap acceptance, and the necessary length that drivers change to the nearside lane from theinside lane is also analyzed in terms of running for the gap acceptance, then calculation modelof minimum net distance between interchanges on eight-lane expressway is constructed. Therecommended value is then put forward.The research of the paper provides strong theoretical basis to the existing specification relating to the length of speed-change lane and minimum net distance between interchangeson mnti-lane expressway, which is of certain realistic significance.