Abstract
This research unveils the factors that affect urban street bottleneck capacity through the use of oblique cumulative plots for traffic analysis on Henry Dunant Road, a busy urban street in Bangkok. Detailed observations on the street reveal that the street bottleneck capacity was affected by several factors such as illegal blocking parked cars, interrupted U-turns from the opposing direction, and interrupted crossover right turns from an access road. In order to analyze the quantitative effects from these factors, four days of traffic data at the study site were collected by video cameras, manually extracted, and plotted using the oblique cumulative curves such that traffic mechanism at the site can be examined by visualizing the changes in flow rates from each different measurement and comparing across observation days. The analysis results show the degrees of how these individual factors affect the street bottleneck capacity.
