Abstract
In this paper an investigation is presented of entrances with a small curve radius and an acceleration length shorter than 200 m, defined as "short entrance lane". The merging speeds are often low and these entrances can become bottlenecks during the peak hours. The Freeway Operation SIMulation model "FOSIM" is calibrated with the analised data collected. With different Freeway volumes and ramp volumes a first attempt has been made to produce a graph, which indicates the free flow area, the transitional area and the congested area.