Researches using existing statistics and data collected from the area of study help officials at decision-making, to improve the region's problems, like the problem of the high rate of accidents in the region, despite the low volume of daily service. The uses of roundabouts in many parts of the world have many advantages over intersections, amongst them are increased safety and capacity and red...

Roundabout is one of the most effective intersection control methods in the world. Although, they have often been used in Iran, but, the methods which are proposed to analyze roundabouts are very old and new regulations are not implemented for analyzing modern roundabouts. There are strong needs to apply new modern analyzing methods for studying roundabouts in Iran. Also, these methods should b...

1 Accurate roundabout capacity models are essential for optimal roundabout 2 designs, but there exists significant differences in the predicted capacities of various 3 state-of-the-art models and in their included explanatory variables. An empirical 4 study into roundabout lane entry capacity was thus performed in the U.K. using data 5 from 35 roundabout entry lanes, where various model forms a...

This paper proposes Multi-stream Minimum Acceptable Space (MMAS) Cellular Automata (CA) models to study unsignalised multi-lane (twoor three-lane) urban roundabouts. Through detailed space considerations, using Cellular Automata (CA) and the Multi-stream Minimum Acceptable Space method, heterogeneity and inconsistency of driver behavior and interactions in cross traffic at entrances of roundabo...

The work is proposed to design a controller of the form known as roundabout scenario trajectory tracking problem. road condition four-leg, single-lane roundabout; reference path given. Due decision choice exits, MPC used test effect weight parameter and target speed on performance controller. Two sets cases are make experimental comparison, see relationship between control parameters conditions...

Although two-lane roundabouts theoretically exhibit excellent operating performance, in practice, safety problems arise because of inappropriate driving behavior. Turbo roundabouts, which are characterized by a much higher level of safety, are alternatives to classic two-lane roundabouts, but the capacity-related benefits derived from such roundabouts remain an open issue. Accordingly, this stu...

This study evaluated drivers' behavior in yielding the right-of-way to sighted and blind pedestrians who stood at different stopping distances from the crosswalk lines at entry and exit lanes at two different roundabouts. The findings demonstrate that drivers' willingness to yield to pedestrians is affected by whether they are attempting to cross at the entry or exit to the roundabout and, unde...

Results of research on roundabouts in the United States are presented in the NCHRP Report 572. The findings and recommendations of this report are important as they will be the basis of the 2010 Highway Capacity Manual methodology for operational analysis of roundabouts. This paper discusses various findings and recommendations of the NCHRP Report 572 on roundabout capacity and level of service...