1 / 27

Quantified road safety target

Quantified road safety target. - Is the effect sustainable?. S.C. Wong The University of Hong Kong Tony Sze Delft University of Technology. Structure of Presentation. Introduction Data Method Results Discussions Conclusions. Introduction. Road safety strategy framework.

Download Presentation

Quantified road safety target

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Quantified road safety target - Is the effect sustainable? S.C. Wong The University of Hong Kong Tony Sze Delft University of Technology

  2. Structure of Presentation • Introduction • Data • Method • Results • Discussions • Conclusions

  3. Introduction Road safety strategy framework • FOCUS: Development of objective-related, cost effective, and practical measures that contribute to target achievement

  4. Social acceptability Capability Ambition Introduction Achievable and challenging road safety target • When a target is too ambitous, it becomes disappointing with no proven effectiveness, and demotivates • When a target is too ‘easy’, and can be achieved without a high level of implementation, complacency is induced • THEREFORE, setting up an appropriate target that strikes a balance among ambition, capability and social acceptability is necessary

  5. Short-term effect on average fatality Introduction Previous work • Wong, S.C., Sze, N.N., Yip, H.F. et al. (2006) Association between setting quantified road safety targets and road fatality reduction. Accident Analysis and Prevention 38, 997-1005.

  6. Long-term effect on trend of fatality Introduction Current perspectives

  7. Data Setting road safety target in OECD countries • 14 OECD countries first set quantified road safety target in 1970s – 1990s • 7 of which further set a new target before the expiration of 1st target • 16 OECD countries have no evidence of target setting till year 2001

  8. Data Fatality data Source of data for current study • International Road Traffic & Accident Database (IRTAD) • World Road Statistics (WRS)

  9. y=0 (reference) Data Sample and study period • Sample • 1st target set in OECD countries during the period 1973-1997 • Study period for the effect of target setting • y = 1: year of target setting • y = Y: target year • or year preceding setting of new target

  10. y=0 (reference) Data Sample and study period • Sample • 1st target set in OECD countries during the period 1973-1997 • Study period for the effect of target setting • y = 1: year of target setting • y = Y: target year • or year preceding setting of new target

  11. Data Comparison group

  12. Data Comparison group (cont’d)

  13. Data Treatment group

  14. Scaling factor of annual fatality number at year y, where y = 0 denotes reference year (year preceding a target setting) Method Normalization of fatality data

  15. Scaling factor of annual fatality number at year y, where y = 0 denotes reference year (year preceding a target setting) Method Normalization of fatality data

  16. Method Qualification test for comparison group Regression analysis • Historical fatality trend in the ‘before’ period • Trend of log-transformed scaling factor, f and year, y, where i = t denotes treatment group i = c (c = 1, 2, 3, … C ) denotes comparison group α denotes time-series trend of ln (f )

  17. Method Qualification test for comparison group Regression analysis • Difference in time-series trend between treatment & comparison group Treatment group Comparison group where δ is a dummy variable to signify a comparison group • Therefore, the regression equation for qualification test,

  18. Method Qualification test for comparison group (cont’d)

  19. Method Qualification test for comparison group (cont’d)

  20. Method Effectiveness evaluation Regression analysis • Regression equation, whereg (y ) = 1 for i = t & y > 0, and g (y ) = 0 if otherwises h (y ) = a + b y • Existence of target, g(y ) • Effect of target, h(y ) • a- absolute change in fatality number; b- change in the trend of fatality number

  21. Method Effectiveness evaluation (cont’d)

  22. (I) a>0, b>0 (II) a>0, b<0 (III) a<0, b>0 (IV) a<0, b<0 Method Effectiveness evaluation (cont’d) a- absolute change in fatality number b- change in the trend of fatality number

  23. Results Effects of quantified road safety target in long term • Immediate fatality reduction- consistent to the results of previous study • Desirable changes in the trend of fatality number • Diminishing the rate of increase • Changing an increase to a decrease • Yielding a greater reduction

  24. Discussion Sustainable goal and target • Rational, motivating and action guiding goal • More modest and short-term targets as interim milestones Comprehensive road safety management framework • Sub-targets for various road safety indicators • Periodoic progress review for different road entities and sub-targets • Robust institutional framework • Strong political foundation

  25. Discussion (cont’d) Target setting and fatality reduction • Intermediate factors between road safety target and fatality reduction • Factors, circumstances and developments that were anticipated prior to target setting

  26. Conclusions Effectiveness of road safety target set in OECD countries (1970s-1990s) • Regression approach effectiveness evaluation • Trend of fatality number in a longer time span • Desirable effect on the trend of fatality number is revealed Future prospects: a sustainable road safety target • Ambitiousness of target • Existence of long-term committment • Use of sub-targets • Presence of detailed road safety program • National income and expenditure on road safety measures

  27. Thank you! Quantified road safety target- Is the effect sustainable? S.C. Wong and Tony Sze

More Related