Sains Ma1aysiana 26(2): 65-81 (1997)                                                                                          Pengajian Kuantitatif/

Quantitative Studies

A Study of Exposure to Accidents at Small Roundabouts

Kamarulzaman Bin Ibrahim

Department of Statistics

Faculty of Mathematical Sciences

Universiti Kebangsaan Malaysia

43600 UKM Bangi, Se1angor D.E. Malaysia

ABSTRACT

Traffic engineers often used the observed number of accidents to evaluate the safety of a particular site. However, if one were to compare a site with another in terms of safety, the use of accident frequency will be of a limited value since no account is taken of exposure to risk. In this study, three different measures of exposure to accidents at small roundabouts were compared. The first measure is the total number of traffic entering the roundabout. The other two measures are the product of cross flows at conflict points and the square root of the product of cross flows at conflict points. In modelling these measures of exposure in relation to accidents, generalised linear modelling technique was used. No conclusive answer was found on the most appropriate measure of exposure.

ABSTRAK

Jurutera trafik selalu menggunakan bilangan kemalangan yang dicerap untuk menilai keselamatan sesuatu lokasi. Bagimanapun, jika seseorang itu ingin membandingkan sesuatu lokasi dengan lokasi yang lain dari sudut keselamatan, penggunaan kekerapan kemalangan adalah terhad kerana pendedahan terhadap risiko kemalangan tidak diambil kira. Dalam kajian ini, perbandingan dibuat terhadap tiga sukatan pendedahan kepada kemalangan di bulatan kecil. Sukatan yang pertama ialah jumlah trafik yang masuk ke bulatan kecil. Dua sukatan lagi ialah hasil darab aliran silang di titik konflik dan punca kuasa dua hasil darab aliran silang di titik konflik. Dalam pemodelan sukatan pendedahan ini berhubung dengan kemalangan, teknik model linear teritlak digunakan. Tiada jawapan yang muktamad didapati tentang sukatan pendedahan yang paling sesuai.

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