Introduction Carl Johnsson, PhD student from Lund University in - - PDF document

Surrogate safety evaluation approach

ICTCT Extra Workshop – Vancouver, 2018 SURROGATE SAFETY MEASURES

Carl Johnsson and Aliaksei Laureshyn

• Carl Johnsson, PhD student from Lund University in Sweden
• Evaluation of surrogate safety indicators
• InDeV EU-project

– Coordinated by Aliaksei Laureshyn

Introduction

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Framework for my research

This presentation

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• Alternative/Complementary method to Accident analysis
• Observation of near-accidents
• The main advantage is that near-accidents occur more

frequently than accidents

What are surrogate safety indicators

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What are surrogate safety indicators

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Relevance Higher frequency Elementary units of exposure Hydén, 1987

Surrogate safety indicators and units of exposure

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Measures risk Measures exposure

At what threshold does a surrogate safety indicator start to measure risk?

Study design

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• 1. At what threshold does a surrogate safety indicator start to

measure risk?

• Data from 4 signalized intersections

– Spain, Poland, Denmark and Norway – 24 hours observed from each site – Right turning motor vehicles vs bicycles

• Hourly meetings/severe events

– Both road users move within the intersection – Manual trajectories for each meeting (one road user in a group) – PET

• Negative binomial regression model from SPSS

Study design

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Early results, PET

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Exposure Risk The tested indicator does not show the expected correlation with the country specific parameters (connected to Risk)

– Lowering the threshold values does also not produce the expected effect

Conclusion from the early results

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Thank you very much for your attention!

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 635895

Visit us on www.indev-project.eu

Carl Johnsson and Aliaksei Laureshyn

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