The dilemma zone studies for safety evaluation at Jl. Lingkar Utara (northern ringroad) high-speed signalized intersection in Yogyakarta

HOSPITAL, Deby, Prof. Dr. Ir. Siti Malkhamah, M.Sc

2009 | Tesis | S2 Magister Sistem dan Teknik Transportasi

High speed signalized intersections are typically associated with vehicle crashes resulting from dilemma -zone problems. Dilemma zones are defined as zones where some drivers may decide to proceed through an intersection in either time or space, whereas others may de cide to stop at the onset of a yellow indication. The yellow interval dilemma is an example of the incompatibility of man -made laws and physically attainable human behaviour. When the yellow signal turns on, the driver approaching a signal controlled inter section, may find himself too close to the intersection to stop, or to stop safely, and yet too far from the intersection to cross the clearing line in a manner compatible with traffic regulations, if the yellow interval duration is too short. The objectiv es of this report are to define the factors which are affect intersection safety at signalized intersection, to figure out the percentage of driver decisions/choices on seeing the yellow signal and who become red light runners and also to characterize driv er behaviour at the onset of an yellow -phase transition by modification scenarios for cases of yellow phase and deceleration rate of vehicle and its comparison. Therefore in this research methodology, the drivers’ speeds are figured to observe the driver behaviour in terms of speeding and the red light running study data were analyzed to know t he drivers’ characteristics . The most important factor in the genesis of accidents at signalized intersections that influenced the dilemma zone problem is human behaviour of drivers. The findings of this issue indicate that a large percentage of drivers facing the yellow signal are caught in a dilemma zone due to high approaching speeds and high deceleration rate. Most drivers when they faced the yellow signal opted to continue the intersection in high speed rather than to stop his vehicle. This driver behaviour on Jl. Lingkar Utara (Northern Ringroad) where most of them which trapped in dilemma zone tend to take a risk or dangerous decision when faced the yellow signal or red to keep on their driving although they become red light runners. Keywords: Dilemma zone; Hi

Kata Kunci : Dilemma zone,high,speed signalized intersection,Driver behaviour,Red light running,Yellow phase signal,deceleration rate