The main function of freeways is to provide free flow of traffic at high speeds. Merging of two freeways should therefore be designed in a way that its impact on the free flow of traffic is minimized. There are two possible ways in which merging sections of freeway are designed. First, merging of freeways with same number of lanes (i.e. number of lanes in the merged freeway equals sum of the number of lanes of two merging freeways) and, second merging of freeways with decreasing number of lanes (i.e. number of lanes in the merged freeway is less than the total number of lanes of the merging freeways). In this study, merging with decreasing number of lanes is under consideration.

To design the merging section of freeways, usually the entire section is divided into three major subsections; ramp, acceleration lane and weaving section. In the Dutch Standards named “Richtlijn Ontwerp Autosnelwegen” along with the design specifications for individual elements of merging section, complete simplified designs are provided for merging sections with decreasing number of lanes for specific vehicle/capacity ratios and design speeds. In this study, we are investigating these designs in relation to the drivers’ behaviour.

Objectives of this research include: 1) studying drivers’ behaviour while driving through merging designs given in the Dutch Standards and 2) comparing the efficiency of the considered designs under various heavy traffic proportions.