1 Towards the Simulation of Ramp Weaving Sections

Motorway weaving sections entail intensive lane changes which lead to high turbulence within such sections. Different methods, such as mathematical modelling, have been adopted to analyse traffic behaviour and to determine weaving section capacity. However, simulation methods have proved to be more effective than other mathematical methods. Therefore, a simulation model has been developed for this purpose and this model has been calibrated and validated with field data from normal and weaving sites. Different configurations of weaving sections are in use, such as “major weave ” which occurs between two major roads and “ramp weave ” that occurs between minor road (i.e. on-ramp) and major road (i.e. motorway). This study focuses on ramp weave only since the data available from sites represent this configuration. Field data was used to calibrate and validate the newly developed simulation model. The results from the newly developed model showed good fit with the field data in terms of calibration and validation. The model has been applied to assess the effect of weaving length under different number of lanes for ramp weave sections, the percentage of heavy goods vehicle and the different volume ratios. The results showed that weaving length has an effect on capacity up to a certain limit, after which its effect dissipates. The presence of heavy goods vehicles also causes a high reduction in the capacity of the weaving section and this reduction has been estimated. Other factors, such as volume ratio, have a significant effect on the capacity of weaving section