01366060

Component

The safety and mobility benefits of roundabouts are increasing their popularity. This is a study of a specific approach at a roundabout that was previously three separate “T” intersections, one of which was a high crash location. A total of 2,366 drivers using that approach were classified by age; those under 20, in their 20s, 30s, 40s, 50s, 60s, and 70 and older. Gender and whether or not a cell phone was used were also recorded. Using Raff’s definition, the critical gap values were calculated and then converted to average control delay times for comparison using four different methods, one of which was physical measurement. It was found that the <20, 70+, and cell phone groups had higher critical gap values, but not enough data was collected within each of these groups to statistically verify the accuracy. Only 26 drivers were under the age of 20; 64 being 70 years old or older; and 162 using a cell phone. The average measured delay times was compared to standard queuing theory and new equations offered by the 2010 edition of the Highway Capacity Manual (HCM2010). It was found that the HCM2010 over-estimates the delay times, which has the potential to give the incorrect impression that a roundabout is not a viable option when it may very well be.

This paper was sponsored by TRB committee ANB75T Roundabouts

01362476

12-2390

English

16p

2012

Transportation Research Board 91st Annual Meeting

Digital/other

Figures; Photos; References; Tables

Age groups; Approach roads; Gender; Highway safety; Mobile telephones; Roundabouts; Traffic delays; Traffic queuing

Bangor (Maine)

Highways; Safety and Human Factors; Society; I83: Accidents and the Human Factor

Transportation Research Board Annual Meeting 2012 Paper #12-2390

TRIS, TRB

Feb 8 2012 5:09PM