An Investigation of the Safety Performance of Roundabouts in Korea Based on a Random Parameters Count Model

Abstract

It is well known that a roundabout is an efficient and safe intersection. However, the safety is generally influenced by the given various conditions. This study analyzed the effects of the geometric and traffic flow conditions on traffic accident frequency at roundabouts, constructed in Korea since 2010. Many previous studies have investigated the efficiency and safety effects of roundabout installation. However, not many studies have analyzed the specific influences of individual geometric elements and traffic flow conditions of roundabouts. Accordingly, this study analyzed the effects of various influencing variables on traffic accident frequency based on a random parameter count model using traffic accident data in 199 roundabouts. Using random parameters that can take into account unobserved heterogeneity, this study tried to make up for the weakness of the fixed parameters model, which constrains estimated parameters to be fixed across all observations. A total of eight variables were determined to be the main influencing factors on traffic accident frequency including the number and width of entry lanes, the presence of pedestrian crossings, the width of the circulatory lanes, the presence of central islands, the radius and number of entry lanes, and traffic volume influence accident frequency. Based on the study results, safer roundabout design and more efficient roundabout operation are expected.

Pemodelan Kondisi Geometrik Jalan Terhadap Potensi Kecelakaan Lalu Lintas

“…Geometri alinyemen horizontal memiliki hubungan kuat dengan kecelakaan lalu lintas (Shiomi et al, 2017) (Sun et al, 2022) (Jima & Sipos, 2022 hal serupa disimpulkan bahwa pengaruh geometrik jalan berpengaruh signifikan terhadap terjadinya kecelakaan (Abebe, 2019). Penelitian serupa menyatakan radius tikungan mempengaruhi frekuensi kecelakaan (Park et al, 2018). Radius tikungan dan jumlah jarak pandang pada lengkung horizontal merupakan faktor utama terjadinya kecelakaan fatal dan cedera pada daerah blackspot di jalan raya (B. H. Lemena et al, 2020) (B. Lemena & Kuleno, 2021.…”

Dönel Kavşak Geometrik Elemanlarının Kavşak Güvenliği Üzerine Etkisinin Literatür Işığında Değerlendirilmesi

“…Yapılmış çalışmalardan dönel kavşaklardaki kaza sıklığının yıllık ortalama günlük trafik ve dönel kavşakların geometrik özellikleri ile ilgili olduğu görülmektedir [12,35,63]. Bununla birlikte dönel kavşaklarda yapılmış diğer çalışmalarda araştırmacılar, uygun geometrik tasarım ve modellemenin trafik güvenliğini önemli ölçüde arttırabileceğini göstermişlerdir [64][65][66][67][68][69][70][71][72]. Aumann [73] ise hazırladığı kılavuzda iyi tasarlanmış bir dönel kavşağı, kavşak tiplerinden en güvenli olanı olarak tanımlamıştır.…”

Evaluating the Safety Performance of Roundabouts

“…Tang [13] indicated that the severity of the accidents and the conflicting intersectional points decline due to the roundabout. However, the performance of the roundabout has been found to be better when the traffic is intermediate as compared to high traffic [2]. Despite this, various researches have confirmed that the modification of the signalized intersection to roundabouts offers an effective way to overcome the frequency of accidents as well as its associated severity [14,15].…”

“…Roundabouts are an alternative intersection control method that is used to improve road safety and convey traffic without widening roadways [1]. Initially, the concept of roundabouts first emerged in the United Kingdom for resolving the problems of traffic circles [2]. The modification of the driving rule, such as yielding of the entering traffic to circulate traffic, set the bases for the formation of the circulatory lanes, leading to the successful implementation of contemporary roundabouts.…”