New Approach to Accident Analysis for Hazardous Road Locations

Abstract

This paper proposes a new approach to the analysis of accidents at hazardous road locations, one that is designed to make these analyses more effective in discriminating between true and false positives, that is, sites whose true expected number of accidents is high and sites where a high recorded number of accidents is predominantly the result of chance variation. The following elements of the proposed approach have not traditionally been part of the analysis of accidents at hazardous road locations: (a) the use of a binomial probability model to estimate the probability that the observed pattern of accidents at a hazardous road location differs from the normal pattern for comparable sites; (b) a two-stage procedure for analysis, in which the first stage consists of an analysis of accidents designed to develop hypotheses about risk factors contributing to the accidents and the second stage is designed to test these hypotheses; (c) the use of a matched-pair, single-blind method for evaluating risk factors that contribute to accidents at hazardous road locations; and (d) the development of clear criteria for concluding whether an apparently hazardous road location actually is. These elements are designed to guard against some pitfalls of the traditional approach to accident analysis for hazardous road locations, including confirmation of analyst expectancies, data mining, and nonspecific criteria for determining whether a hazardous road location is a true or false positive. The approach is illustrated through simulated data.

Get full access to this article

View all access options for this article.

References

Elvik

Evaluations of Road Accident Black Spot Treatment: A Case of the Iron Law of Evaluation Studies?

Accident Analysis and Prevention, Vol. 29, 1997, pp. 191–199.

Hauer

Identification of Sites with Promise. In Transportation Research Record 1542, TRB, National Research Council, Washington, D.C., 1996, pp. 54–60.

Hauer

The Road Ahead. Journal of Transportation Engineering, Vol. 131, pp. 333–339, 2005.

Hauer

Quaye

and Liu

On the Use of Accident or Conviction Counts to Trigger Action. In Transportation Research Record 1401, TRB, National Research Council, Washington, D.C., 1993, pp. 17–25.

Cheng

and Washington

S. P.

Experimental Evaluation of Hotspot Identification Methods. Accident Analysis and Prevention, Vol. 37, No. 5, Sept. 2005, pp. 870–881.

Elvik

Traffic Safety. In Handbook of Transportation Engineering ( Kutz

, ed.). McGraw-Hill, New York, 2004, Ch. 16.

Danielsson

Estimation of the Effects of Countermeasures on Different Types of Accidents in the Presence of Regression Effects. Accident Analysis and Prevention, Vol. 20, 1988, pp. 289–298.

Jarrett

D. F.

Abbess

C. R.

and Wright

C. C.

Empirical Estimation of the Regression-to-Mean Effect Associated with Road Accident Remedial Treatment. Proc., Traffic Safety Theory and Research Methods, Session 2: Models or Evaluation. SWOV, Institute for Road Safety Research, Leidschendam, Netherlands, 1988.

Harwood

D. W.

Potts

I. B.

Smiley

Bahar

and Hauer

Safety Analyst: Software Tools for Safety Management of Specific Highway Sites. White paper for Module 2: Diagnosis and Countermeasure Selection. FHWA, 2002.

10.

Brüde

and Larsson

“Farliga” korsningar på det statliga vägnätet. Analys och åtgärdsförslag. VTI-meddelande 299. Linköping, Statens Väg- och Trafikinstitut, 1982.

11.

Rosenthal

and Rubin

D. B.

Interpersonal Expectancy Effects: The First 345 Studies. Behavioral and Brain Sciences, Vol. 3, 1978, pp. 377–415.

12.

Kononov

Identifying Locations with Potential for Accident Reductions: Use of Direct Diagnostics and Pattern Recognition Methodologies. In Transportation Research Record: Journal of the Transportation Research Board, No. 1784, Transportation Research Board of the National Academies, Washington, D.C., 2002, pp. 153–158.

13.

vegvesen

Statens

. Håndbok 115: Analyse av ulykkessteder. Vegdirektoratet, Oslo, Norway, 1983.