Estimating the safety performance of urban road transportation networks.

Transportation planning models are typically used to estimate future traffic patterns, peak period traffic, travel time, and various environmental or other related traffic flow characteristics. Unfortunately, traffic safety is seldom, if ever, explicitly considered proactively during the transportation planning process. This omission is attributed to various factors, including the lack of available tools needed to estimate the number of crashes during this process. To help fill this void, the research on which this paper is based aimed, as a primary objective, to develop a tool that would allow the estimation of crashes on digital or coded urban transportation networks during the planning process. The secondary objective of the research was to describe how the predictive models should be applied on these networks and explain the important issues and limitations surrounding their application. To accomplish these objectives, safety performance functions specifically created for this work were applied to two sample digital networks created with the help of EMME/2, a software package widely used in transportation planning. The results showed that it is possible to predict crashes on digital transportation networks, but confirmed the reality that the accuracy of the predictions is directly related to the precision of the traffic flow estimates. The crash predictions are also sensitive to how the digital network is coded, and it is shown how appropriate adjustments can be made.

[1]  Bhagwant Persaud,et al.  Calibration and Transferability of Accident Prediction Models for Urban Intersections , 2002 .

[2]  I J Burrow,et al.  NETWORK SAFETY MANAGEMENT - A QUANTITATIVE APPROACH , 1995 .

[3]  S-P Miaou,et al.  MEASURING THE GOODNESS-OF-FIT OF ACCIDENT PREDICTION MODELS , 1996 .

[4]  Ezra Hauer,et al.  Estimation of safety at signalized intersections , 1988 .

[5]  Tarek Sayed,et al.  Evaluating Safety of Urban Arterial Roadways , 2001 .

[6]  Linda Mountain,et al.  Estimating accidents at junctions using routinely available input data. , 1996 .

[7]  Shaw-Pin Miaou,et al.  Modeling Traffic Crash-Flow Relationships for Intersections: Dispersion Parameter, Functional Form, and Bayes Versus Empirical Bayes Methods , 2003 .

[8]  R Kulmala,et al.  SAFETY AT RURAL THREE- AND FOUR-ARM JUNCTIONS. DEVELOPMENT AND APPLICATION OF ACCIDENT PREDICTION MODELS. , 1995 .

[9]  H. Al-Deek,et al.  The potential impact of advanced traveler information systems (ATIS) on accident rates in an urban transportation network , 1993, Proceedings of VNIS '93 - Vehicle Navigation and Information Systems Conference.

[10]  Shane Turner,et al.  USING ACCIDENT PREDICTION MODELS IN AREA WIDE CRASH REDUCTION STUDIES , 1998 .

[11]  R. M. Oliver,et al.  Flows in transportation networks , 1972 .

[12]  A. Nicholson,et al.  ESTIMATING ACCIDENTS IN A ROAD NETWORK , 1996 .

[13]  Bani K. Mallick,et al.  ROADWAY TRAFFIC CRASH MAPPING: A SPACE-TIME MODELING APPROACH , 2003 .

[14]  Mike McDonald,et al.  The Network Safety Effects of Dynamic Route Guidance , 1999, J. Intell. Transp. Syst..

[15]  U Bruede,et al.  Design of major urban junctions : Accident prediction models and empirical comparisons , 1998 .

[16]  Mike Jackett.  Accident Rates on Urban Routes - 1992 Update , 1993 .

[17]  Said M. Easa,et al.  Traffic Assignment in Practice: Overview and Guidelines for Users , 1991 .

[18]  D Lord,et al.  SAFETY ISSUES IN DYNAMIC ROUTE GUIDANCE , 1999 .

[19]  G Maycock,et al.  ACCIDENTS AT 4-ARM ROUNDABOUTS , 1984 .

[20]  Bhagwant Persaud,et al.  Accident Prediction Models With and Without Trend: Application of the Generalized Estimating Equations Procedure , 2000 .

[21]  Dominique Lord,et al.  The prediction of accidents on digital networks, characteristics and issues related to the application of accident prediction models , 2000 .

[22]  M J Maher,et al.  A comprehensive methodology for the fitting of predictive accident models. , 1996, Accident; analysis and prevention.

[23]  P C Hughes,et al.  Accident - and travel time-minimising routeing patterns in congested networks , 1993 .

[24]  E Hauer,et al.  SAFETY ANALYSIS OF ROADWAY GEOMETRIC AND ANCILLARY FEATURES , 1996 .

[25]  Fred L. Mannering,et al.  Negative binomial analysis of intersection accident frequencies , 1996 .

[26]  Ezra Hauer,et al.  PREDICTION OF THE EXPECTED SAFETY PERFORMANCE OF RURAL TWO-LANE HIGHWAYS , 2000 .

[27]  L Mountain,et al.  Accident prediction models for roads with minor junctions. , 1996, Accident; analysis and prevention.

[28]  Y. She.  Urban Transportation Networks: Equilibrium Analysis with Mathematical Programming Methods , 1985 .