Lane under-utilisation is commonly experienced at signalised intersections. This has significant effects on intersection capacity, which has consequences for congestion, especially in the urban environment. Ultimately, this results in overly optimistic design predictions. Little research has been undertaken in New Zealand and Australia on this topic. The main focus of this study was to determine the effect of short kerbside through-lanes on utilisation.
The results of the study show a positive relationship between lane length and utilisation; however, it was not found to be a strong link. Increasing auxiliary lane length only resulted in minor improvements in lane utilisation. Based on the small sample analysed in this study, it is therefore concluded that increasing the total upstream and downstream length of the short kerbside through-lane is likely to result in only marginally higher rates of use for both 2-laners and 3-laners.
Low-cost alternative/improvement treatments have been suggested as a part of this study. Since a relatively small sample was studied, further research with a larger sample is recommended to further confirm these findings and measure the significance of the results. Further research will also enable the other causes of lane under-utilisation to be determined and measured.