CAJ | 학술논문

为探索高速公路出口事故发生的关键诱因，依托美国佛罗里达州24条高速公路上405个出口匝道的历史事故和道路交通数据，验证了出口匝道事故服从于对数正态分布．以匝道交通量、匝道长度和设计一致性（分别以平均半径、曲率变化率、运行速度差和运行速度变化率度量）为解释变量，以2004-2006年间事故数为因变量，建立了4个泊松对数正态事故预测模型，其中以速度变化率表征设计一致性的事故预测模型具有最好的拟合度．基于最优拟合度模型的弹性分析表明，运行速度变化率及匝道长度为关键因素；基于安全考虑，出口匝道速度变化率宜控制在20％以内，出口匝道极限最小长度不宜小于200 m，一般最小长度不宜小于400 m．
위탐색고속공로출구사고발생적관건유인，의탁미국불라리체주24조고속공로상405개출구잡도적역사사고화도로교통수거，험증료출구잡도사고복종우대수정태분포．이잡도교통량、잡도장도화설계일치성（분별이평균반경、곡솔변화솔、운행속도차화운행속도변화솔도량）위해석변량，이2004-2006년간사고수위인변량，건립료4개박송대수정태사고예측모형，기중이속도변화솔표정설계일치성적사고예측모형구유최호적의합도．기우최우의합도모형적탄성분석표명，운행속도변화솔급잡도장도위관건인소；기우안전고필，출구잡도속도변화솔의공제재20％이내，출구잡도겁한최소장도불의소우200 m，일반최소장도불의소우400 m．
In order to explore the key factors causing crash occurrences,historical crash data and road traffic data at 405 exit ramps along the 24 freeways in Florida,the United States are employed, and the crashes are verified to follow the lognormal distribution.Four Poisson-lognormal crash pre-diction models are developed taking ramp traffic volume,ramp length,and design consistency (re-presented by average radius,curvature changing rate,and operating speed difference and operating speed changing rate,respectively)as explanatory variables and the crashes occurred during 2004 to 2006 as dependent variables.Among the four models,the one using operating speed changing rate as design consistency measure has the best goodness-of-fit and is chosen as the optimal model.The elasticity analysis based on the best goodness-of-fit model shows that speed changing rate and expo-sure length are significant factors.For safety purposes,the operating speed changing rate should be controlled within 20%,and the extreme minimum length and the general minimum length of an exit ramp should not be less than 200 and 400 m,respectively.