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Surrogate Measures of Safety


The purpose of the SMoS library is to provide easy access to must-read literature on the subject of surrogate measures, with particular focus on the older publications that might exist only in paper form but are still highly relevant. We recommend also browsing the materials of the previous conferences as relevant contributions are frequently found there, too.

Tarko A. P. (2019) Measuring Road Safety Using Surrogate Events. Elsevier. ISBN 978-0-12-810504-7.

Tarko, A. P. (2018) ‘Surrogate Measures of Safety’ in D. Lord, S. Washington (Eds.) ‘Transport and Sustainability, Volume 11 – Safe Mobility: Challenges, Methodology and Solutions’ (pp. 383–405). Emerald Publishing Limited. ISBN 978-1-78635-224-8.

Johnsson, C., A. Laureshyn, T. De Ceunynck (2018) ‘In search of surrogate safety indicators for vulnerable road users, a review of surrogate safety indicators’. Transport Reviews 38 (6), pp. 765-785.

Chang, A., N. Saunier, A. Laureshyn (2017) ‘Proactive methods for road safety analysis’. SAE International. White paper.

Laureshyn, A., C. Johnsson, T. D. Ceunynck, Å. Svensson, M. de Goede, N. Saunier, P. Włodarek, A. R. A. van der Horst, S. Daniels (2016) ‘Review of current study methods for VRU safety. Appendix 6 – Scoping review: surrogate measures of safety in site-based road traffic observations’. InDeV, Horizon 2020 project. Deliverable 2.1 – part 4.

Zheng, L., K. Ismail, X. Meng (2014) ‘Traffic conflict techniques for road safety analysis: open questions and some insights’. Canadian Journal of Civil Engineering 41 (7), pp. 633-641.

Tarko, A., G. Davis, N. Saunier, T. Sayed, S. Washington (2009) ‘Surrogate measures of safety’. TRB Subcommittee on Surrogate Measures of Safety ANB20(3). White paper.

Chin, H. C., S. T. Quek (1997) ‘Measurement of traffic conflicts’. Safety Science 26 (3), pp. 169-185.

Hydén, C. (1996) ‘Traffic conflicts technique: state-of-the-art’ in H. H. Topp (Ed.) ‘Traffic safety work with video-processing’. Transportation Department, University Kaiserlauten.

Hauer, E. (198x) ‘Traffic conflict technique – fundamental issues’.

Hakkert, A. S. (198x) ‘Guidelines for the conduct of traffic conflict studies’. International Committee for Traffic Conflict techniques (ICTCT).

Hauer, E. (1978) ‘Traffic conflict surveys: some study design considerations’. Transport and Road Reasearch Laboratory. Supplementary report 352.

Hauer, E. (1977) ‘Indirect measurement of safety – the conflict method’. University of Toronto (draft).

First workshop on traffic conflicts

26–27 September 1977, Oslo, Norway


S. J. Older, J. Shippey. Traffic Conflict Studies in the United Kingdom

V. A. Guttinger. Conflict Observation Techniques in Traffic Situations

P. Cooper. State-of-the-art: report on traffic conflict research in Canada

F. H. Amundsen, H. O. E. Larsen. Traffic Conflicts Techniques—Status in Norway

U. Linderoth, L. Ringhagen. Traffic Study Technique at Rural Intersections

G. Malaterre, N. Muhlrad. A Conflict Technique

W. T. Baker, W. D. Glauz. The Traffic Conflict Experience in the United States

M. J. Merilinna. Use of the Traffic Conflicts Technique in Finnish Road Conditions

A. S. Hakkert, D. Balasha, M. Livneh, J. Prashker. Irregularities in Traffic Flow as an Estimate of Risk at Intersections

C. Hydén. A Traffic-Conflicts Technique for Examining Urban Intersection Problems

G. Zimmermann, B. Zimilong, H. Erke. The Development of the Traffic Conflicts Technique in the Federal Republic of Germany

S. Oppe. What Task is a Traffic Conflicts Technique intended for?

N. O. Jørgensen. Danish ‘Traffic Conflict’ Definition

The original traffic conflict definition suggested by one of the working groups during the workshop was formulated as:

“A traffic conflict is an observable situation in which two or more road users approach each other in space and time to such an extent that there is a risk of collision if thier movements remain unchanged”.

It can be found on p. 135 of the Proceedings.

Second international traffic conflicts technique workshop

10–12 May 1979, Paris, France


T. K. Datta. Accident Surrogates for Use in Analyzing Highway Safety Hazards

G. Nilsson. A structure of needs of risk exposures for road accident analysis

D. Balasha, A. S. Hakkert, M. Livneh. A quantitative definition of the near accident concept

G. Malaterre, N. Muhlrad. Conflicts and accidents as tools for a safety diagnosis

P. Storr, J. Wennell, M. R. C. McDowell. A microprocessor based system for traffic data collection

J. Wennell, P. Storr, J. Darzentas, M. R. C. McDowell. Empirical studies of driver behaviour at T-junctions and use of a simulation model to study conflicts

A. Lightburn, C. I. Howarth. A study of observer variability and reliability in the detection and grading of traffic conflicts

B. R. Spicer, A. H. Wheeler, S. J. Older. Variation in vehicle conflicts at T-junction and comparison with recorded collisions

H. S. Ludvigsen. Traffic conflicts experience in Denmark

J. Darzentas, V. Holmes, M. R. C. McDowell. A pilot study of conflicts at a T-junction on winter evening rush-hours

K. J. Höfner, A. Schützenhöfer. Conflict research in traffic

L. Schützenhöfer. Evaluation of a new design of pedestrian crossing with TCT

H. Gstalter. Pedestrian conflicts technique (PCT)

B. Zimolong. Traffic conflicts at urban junctions

A. R. A. van der Horst, R. M. M. Symonsma. Bahavioural study by the institute for perception IZF-TNO

Third international workshop on traffic conflicts techniques

April 1982, Leidschendam, The Netherlands


NATO advanced research workshop on international calibration study of traffic conflict techniques

25–27 May 1983, Copenhagen, Denmark


Malmö calibration study

Grayson, G. B. (1984) The Malmö study: a calibration of traffic conflict techniques. SWOV. R-84-12.

van der Horst, A. R. A. (1984) The ICTCT calibration study at Malmö: a quantitative analysis of video recordings. Institute for Perception TNO. IZF 1984-37.

Trautenfels calibration study

Kraay, J. H., R. van der Horst (1985) The Trautenfels study: a diagnosis of road safety using the Dutch conflict observation technique DOCTOR. SWOV. R-85-53.

Zaidel, D., I. Hocherman, S. Hakkert (198x) ‘Safety analysis of the Trautenfels junction’. Transportation Research Institute, Technion.

XXXX (1985x) ‘Conflict studies at two junctions in Austria—the summary report of the Finnish and the Swedish teams’. VTT and Tekniska Högskolan i Lund. Research report 515.

Almqvist, S. (1988) ‘International conflict studies in Austria’. Tekniska Högskolan i Lund. LUTVDG/(TVTT-7073)/1-87/1988. (contains several reports)

Workshop on traffic conflicts and other intermediate measures

8–10 September 1986, Budapest, Hungary


F. Hajek. The human factor effect on the road transport safety

E. Bakalar. The forms and contents of the supervising Methodology with respect to road and city transport psychology

V. Rehnova. The analysis of traffic accident causes made by human factor

T. Rotter. The analysis of drivers’ escapes from an accident place as a sourse of information about traffic safety

G. B. Grayson. Intermediate measures for traffic safety—an overview

N. Muhlrad. Application of traffic conflicts and other intermediate measures—an overview

G. Zimmermann. Situation-related safety criteria in road traffic

P. Harmath. Speed-selection in conflict situation

I. Hochermann. The use of systematic behavioural observations to evaluate a change from two to one-way street

R. van der Horst. Road users’ decision making in traffic: some examples

W. T. Baker. Orgin, validation and implementation of the traffic conflict technique (TCT) in the U.S.

L. Ekman. The development of the Swedish traffic conflict technique

A. R. A. van der Horst, R. J. Kraay. The Dutch conflict technique – DOCTOR

R. Risser. Development of traffic conflict techniques in Austria

J. Mortelmans. Traffic conflicts and other intermediate measures in safety evaluation

J. S. Swain. The traffic conflicts technique training package

D. Antov. The use of traffic conflicts technique on urban non signalised intersections

M. Gledec. Application of traffic conflict technique and driver performance measures in analysis of hazardous crossroads

M. Draskoczy. First experences with the application of traffic conflicts technique

R. Kulmala. The effects of a varying speed limit at a highway junction

G. Brown. Application of traffic conflicts for intersection hazards and improvements

S. Tykesson. The usage of traffic conflict technique on the Swedish national road network

R. Risser. Application of traffic conflict techniques in Austria

S. Oppe. Evaluation of traffic conflict techniques

C. Hydén. Evaluation of TCT:s, validation results

P. Gårder. Theory for ‘strong’ validation

S. Almqvist. International calibration of conflict techniques—ICTCT studies in Malmö and Treutenfels

R. Risser. The ‘Treutenfels study’

S. Oppe. The international calibration of conflicts—a summary of the results

Austrian TCT

Risser, R., W. D. Zuzan, W. Tamme, J. Steinbauer, A. Kaba (1991) ‘Handbuch zur Erhebung von Verkehrskonflikten mit Anleitungen zur Beobachterschulung’ (in German) ‘Handbook for the collection of traffic conflicts with instructions for observers’ training’. Literas Universitätsverlag.

Belgian TCT

Mortelmans, J., A. Vits, L. Venstermans, M. van Essche, M. Boogaerts, E. Vergisson (1986) ‘Analyse van de verkeersveiligheid met behulp van de Bijna-Ongevallen methode’ (in Dutch) ‘Analysis of road safety by means of the near-accident method’. Katholieke Universiteit Leuven, Departement Bouwkunde.

Brittish TCT

Baguley, C. J. (1984) ‘The British traffic conflicts technique’. NATO advanced research workshop on international calibration study of traffic conflict techniques 1984, Copenhagen, Denmark.

Canadian TCT

Sayed, T., S. Zein (1999) ‘Traffic conflict standards for intersections’. Transportation Planning & Technology 22, pp. 309-323.

Brown, G. R. (1994) ‘Traffic conflicts for road user safety studies’. Canadian Journal of Civil Engineering.

Brown, G., A. Chau, B. DeCastilho, F. Navin (1984) ‘Traffic conflict procedure and validation’. University of British Columbia. Department of Civil Engineering, Transport Safety Research Group.

Cooper, P. J. (1973) ‘Predicting intersection accidents: the use of conflicts and other models based on traffic flow parameters to predict accident experience at non-signalised intersections’. Ministry of Transport, Ottawa, Canada.

Checz TCT

Kocárková, D. (2012) ‘Traffic Conflict Techniques in Czech Republic’. SIIV – 5th International Congress – Sustainability of Road Infrastructures, 29-31 October 2012 2012, Rome, Italy.


Kraay, J. H., A. R. A. van der Horst, S. Oppe (2013) ‘Manual conflict observation technique DOCTOR’. Foundation Road safety for all, The Netherlands.

van der Horst, A. R. A., R. J. Kraay (1986) ‘The Dutch conflict technique – DOCTOR’. Workshop on traffic conflicts and other intermediate measures, 8-10 September 1986 1986, Budapest, Hungary.

Finnish TCT

Kulmala, R. (1984) ‘The Finnish traffic conflict technique’. NATO advanced research workshop on  international calibration study of traffic conflict techniques 1984, Copenhagen, Denmark.

French TCT

Muhlrad, N., G. Dupre (1984) ‘The French conflict technique’. NATO advanced research workshop on  international calibration study of traffic conflict techniques 1984, Copenhagen, Denmark.

German TCT

Erke, H., H. Gstalter (1985) ‘Verkehrskonflikttechnik – Handbuch für die Durchführung und Auswertung von Erhebungen’ (in German) ‘Traffic conflict technique – manual’. Unfall- und Sicherheitsforschung Straßenverkeh. Heft 52.

Erke, H. (1984) ‘The traffic conflict technique of the Federal Republic of Germany’. NATO advanced research workshop on  international calibration study of traffic conflict techniques 1984, Copenhagen, Denmark.

Swedish TCT

Laureshyn, A., A. Varhelyi (2020) ‘The Swedish Traffic Conflict technique: observer’s manual’. Transport & Roads, Department of Technology & Society, Faculty of Engineering, LTH, Lund University.

Shbeeb, L. (2000) ‘Development of a traffic conflicts technique for different environments – a comparative study of pedestrian conflicts in Sweden and Jordan’. Doctoral thesis. University of Lund, Lund Institute of Technology, Department of Technology and Society, Traffic Engineering.

Svensson, Å. (1998) ‘A method for analysing the traffic process in a safety perspective’. Doctoral thesis. University of Lund, Lund Institute of Technology, Department of Traffic Planning and Engineering.

Linderholm, L. (1992) ‘Traffic Safety Evaluation of Engineering Measures: Devolopment of a Method and its Application to How Physical Lay-Outs Influence Bicyclists at Signalized Intersections’. Doctoral thesis. Lund University, Department of Traffic Planning and Engineering. LUTVDG/(TVTT-1011)/1-173/(1992) & Bulletin 105.

Svensson, Å. (1992) ‘Vidareutveckling och validering av den svenska konflikttekniken’ (in Swedish) ‘Further development and validation of the Swedish traffic conflict technique’. Lund University, Institute of Technology, Dept. of Traffic Planning & Engineering.

Hydén, C. (1987) ‘The development of a method for traffic safety evaluation: the Swedish traffic conflict technique’. Doctoral thesis. Lund University, Department of Traffic Planning and Engineering. Bulletin 70.

Gårder, P. (1982) ‘Konfliktstudier i landsvägskorsningar’ (in Swedish) ‘Conflict stidies in rural intersections’. Institutionen för Trafikteknik, LTH, Lund. Bulletin 42.

Linderholm, L. (1981) ‘Vidareutveckling av konflikttekniken för riskbestämning i trafiken’ (in Swedish) ‘Further development of conflict technique for in traffic risk assessment’. Lund University, Dept. of Traffic Planning and Engineering, Lund, Sweden. Rapport 7025.

Hyden, C., P. Gårder (1977) ‘Konfliktstudier i landsvägskorsningar: redovisning av två pilotstudier’ (in Swedish) ‘Conflict studies at rural intersections: two pilot studies’. Institutionen for trafikteknik, LTH. LUTVDG/(TVTT-7008)/1-73/(1977).

Hydén, C. (1977) ‘A traffic conflict technique for determining risk’. University of Lund, Lund Institute of Technology, Department of Traffic Planning and Engineering. LUTVDG/(TVTT-3005)/1-95/(1977) & Bulletin 15 B.

Hydén, C. (1975) ‘Relations between conflicts and traffic accidents’. University of Lund, Lund Institute of Technology, Department of Traffic Planning and Engineering. Project progress report.


Parker, M. R., C. V. Zegeer (1989) ‘Traffic Conflict Techniques for Safety and Operation’. US Department of Transportation, Federal Highway Administration. FHWA-IP-88-027.

Migletz, D. J., W. D. Glauz, K. M. Bauer (1985) ‘Relationships between traffic conflicts and accidents’. U.S. Department of Transportation, Federal Highway Administration. FHWA/RD-84/042.

Glauz, W. D., D. J. Migletz (1980) ‘Application of traffic conflict analysis at intersection’. Transportation Research Board. NCHRP Report 219.

Glennon, J. C., B. A. Thorson (1975) ‘Evaluation of traffic conflict technique’. Midwest Research Institute. Final report MRI project No. 3825-E.

Baker, W. T. (1972) ‘An evaluation of the traffic conflicts technique’. 51st Annual Meeting of the Highway Research Board 1972.

Perkins, S. R., J. I. Harris (1967) ‘Criteria for Traffic Conflict Characteristics: Signalized Intersections’. General Motors Corporation. Electro-Mechanical Department. Research Publication GMR-632.

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1230 Wien, AUSTRIA
Tel. +43 1 5041546


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