Assessing the Safety Effects of Reduction of Speed Limit on Urban Roads

Seung-oh Son; Juneyoung Park; Minwoo Kim; Byongho Choe

doi:10.7470/jkst.2019.37.6.514

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2019 Vol.37, Issue 6 Preview Page

Article

Assessing the Safety Effects of Reduction of Speed Limit on Urban Roads 도시부 도로 제한속도 하향 사업 안전성 효과평가

31 December 2019. pp. 514-524

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Abstract

This study evaluates the safety effectiveness of speed limit reduction on urban roads by estimating crash modification factors (CMF) using observational before and after methods. For the analysis, the study applied three methods: (1) Naive before-after method, (2) Comparison group (CG) method, (3) Empirical bayes (EB) method, proposed by the Highway Safety Manual (HSM). Observational before-after studies are well known approaches for evaluating safety impact (i.e., CMF) of roadway treatments and policies. The CMFs were calculated for speed limit reduction on urban roadways in Daegu Metropolitan City. Crash data and traffic volume data from 2012 to 2017 were collected for this study. In general, the results show that speed limit reduction on urban roads has positive effectiveness in terms of crash reduction and road safety.

Keywords

crash modification factor (CMF)

empirical bayes

highway safety manual (HSM)

observational before-after study

safety performance function (SPF)

speed limit

본 연구는 차량으로 인한 교통사고 가능성과 심각도를 줄이고 보행자, 자전거 등 교통약자를 보호하기 위해 시행되는 안전속도 5030 사업의 안전성을 평가하였다. 도시부 도로의 제한속도 하향 후 사고 건수 기반의 안전성 개선 효과를 분석하기 위해 미국 Highway Safety Manual (HSM)에서 제시하고 있는 전후 비교분석 방법론 중 (1) 단순 비교방법(Naive before-after method), (2) 비교그룹 방법(Comparison group method, CG), (3) 경험적 베이즈 방법(Empirical bayes method, EB) 3가지 방법론을 활용하였다. 이 방법론을 활용하여 5030 속도 하향 사업 정책의 시범운영이 시행된 대구광역시를 대상으로 2012년부터 2017년까지 발생한 사고를 시행 시점 전후 1년으로 구분하여 CMF를 산출하였다. 특히 안전성능함수(Safety performance functions, SPF) 개발을 통해 도로의 사고 발생 핵심 Exposure를 고려한 안전성 효과평가를 수행하였다. 분석결과 도시부 제한속도 하향은 사고감소 등 안전성 측면에서 긍정적인 효과가 있는 것으로 나타났다. 본 연구는 향후 국내 도시부 도로를 대상으로 적용될 속도 하향 정책 확대에 유의한 역할을 할 것으로 기대된다. 나아가 운영 효율성, 환경성의 관점에서 추가적인 연구가 수행된다면 정책확대를 위한 전략수립 및 시행 사후평가에서 핵심적 역할을 할 수 있을 것으로 기대된다.

키워드

사고수정계수(CMF)

경험적 베이즈 방법론

도로안전편람(HSM)

관측적 사전사후 분석 방법론

안전성능함수(SPF)

제한속도 하향

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Information

Publisher :Korean Society of Transportation
Publisher(Ko) :대한교통학회
Journal Title :Journal of Korean Society of Transportation
Journal Title(Ko) :대한교통학회지
Volume : 37
No :6
Pages :514-524
Received Date : 2019-11-29
Revised Date : 2019-12-17
Accepted Date : 2019-12-27
DOI :https://doi.org/10.7470/jkst.2019.37.6.514

Journal of Korean Society of Transportation ISSN:1229-1366(Print) 2234-4217(Online) 대한교통학회지

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