1. Research Engineer, PhD Michael Sørensen · Institute of Transport Economics · mis@toi.no · + 47 22 57 39 10 · 23/4-2008 From Black Spots to Grey Road Sections - What is the Right Way? Michael Sørensen Research Engineer, PhD Institute of Transport Economics

2. Research Engineer, PhD Michael Sørensen · Institute of Transport Economics · mis@toi.no · + 47 22 57 39 10 · 23/4-2008 1 Background for presentation PhD project: Hazardous road sections in rural areas EU project: Black Spot Management and Network Safety Management (RIPCORD)

3. Research Engineer, PhD Michael Sørensen · Institute of Transport Economics · mis@toi.no · + 47 22 57 39 10 · 23/4-2008 2 Background for project 1) What do we mean with NSM and RSI? 2) Where do NSM and RSI differ and overlap? 3) Do we need both NSM and RSI? BSM: Long tradition and is now considered as ineffective NSM: Supplement to BSM in the last 5-10 years ( Identification, analysis and treatment of hazardous (grey) road sections) RSI: Supplement to BSM and RSA in the last 5-10 years RSA: Adopted in more and more countries

4. Research Engineer, PhD Michael Sørensen · Institute of Transport Economics · mis@toi.no · + 47 22 57 39 10 · 23/4-2008 3 Objective, focus and method  Objective –Clarify the basis philosophy for NSM –Evaluate how NSM differ from BSM and RSI –Evaluate if NSM is needed or if focus should be on RSI  Focus  NSM in Denmark (main roads in rural areas)  Method  Literature survey of exiting method and scientific articles  Interview with 18 Danish key persons  Development of a Danish method for NSM  Analysis of treatment suggestions for 9 grey road sections

5. Research Engineer, PhD Michael Sørensen · Institute of Transport Economics · mis@toi.no · + 47 22 57 39 10 · 23/4-2008 4 A new Danish method for NSM - Category and severity based identification RPI: RWACD: AWACD: 4: Reduction potential index Recorded accident cost weighted accident density Average accident cost weighted accident density Estimered identification criterion for Denmark Definition: Uniform road sections (2-10 km), where RPI > 4 (Largest potential for “saving” the most serious accidents) RPI = RWACD – AWARD > 4 ACD: W: Accident density for accidents with different severity Weight for accidents with different severity

6. Research Engineer, PhD Michael Sørensen · Institute of Transport Economics · mis@toi.no · + 47 22 57 39 10 · 23/4-2008 5 Weights Accident costs AC ser = (CP killed ∙ x killed ) + (CP ser ∙ x ser ) + (CP min ∙ x min ) + CPr acc AC min = (AC min ∙ x min ) + CPr acc AC prop = CPr acc Costs related to people and property damage CP killed = 10,404,000 Dkk CP ser = 1,085,000 Dkk CP min = 295,000 Dkk CPr acc = 100,000 Dkk Number of injured road users x Killed : Killed per accident x ser : Serious injured per accident x min : Minor injured per accident

7. Research Engineer, PhD Michael Sørensen · Institute of Transport Economics · mis@toi.no · + 47 22 57 39 10 · 23/4-2008 6 Identification - an example  Ringkøbing County and Viborg County  1.561 km  290 sections  Average length: 5,4 km  18 grey road section  Grey road sections comprise 4-8 % of the road network Ringkøbing County

8. Research Engineer, PhD Michael Sørensen · Institute of Transport Economics · mis@toi.no · + 47 22 57 39 10 · 23/4-2008 7 Different identification methods Reference to population of site Section length Reference to normal safety level Recorded or expected number Accident severity considered Accident period DenmarkYes2-10 km Yes, Category analysis Recorded Yes, Weights for 4 different categories of accident 5 years GermanyYes3-10 km Yes, Category analysis Recorded Yes, Weights for 3 different categories of accident 3 years NorwayYes 1 km (more) Yes, Accident prediction models Expected Yes, Weights for 4 different categories of injured 8 years USAYes Several miles Yes, Accident prediction models Expected Yes, Possible to select the most severe accident Optionally

9. Research Engineer, PhD Michael Sørensen · Institute of Transport Economics · mis@toi.no · + 47 22 57 39 10 · 23/4-2008 8 NSM compared with RSA, RSI, and BSM Philo- sophy Identifi- cationAnalysisSeverityLength Frequ- encyWhen RSAProactiveNew roads Not accident based - All new roads Once 0-1 year after opening RSIProactive Not accident based -2-10 km Every 2-4 year Over 3-4 years after opening NSM Pro- and reactive Accident based Accident based and general problems Included2-10 km Every 2-4 year Over 5 years after opening BSMReactive Accident based Only accident based Not included Under 0.5 km Every 1-2 year Over 5 years after opening

10. Research Engineer, PhD Michael Sørensen · Institute of Transport Economics · mis@toi.no · + 47 22 57 39 10 · 23/4-2008 9 Assessment of method and philosophy  An systematic evaluation of 108 measures proposed on 9 grey road sections  71 % are only proactive (relate only to problems identified in the road inspection)  Only 29 % of the measures have both a reactive and proactive nature (relate both to problems identified in the accident analysis and in the road inspection) Road sectionABCDEFGHITotal Remedial and preventive73133523431 Only preventive91171359651277 The nature of measures proposed on 9 grey road sections

11. Research Engineer, PhD Michael Sørensen · Institute of Transport Economics · mis@toi.no · + 47 22 57 39 10 · 23/4-2008 10 Conclusion – NSM is not the way  The category and severity based method for identification is better than the options, which the Danish road authorities have at the present moment  However, it is difficult to identify site-specific local accident and injury factors on the grey road sections  The analysis gets the nature of being a general road inspection (RSI) with attention on standard improvements  Discrepancy between philosophy and actual work: accident based identification and not accident based analysis and treatment  Road inspections and standard improvements contribute to traffic safety improvements, but the ranking may be done in a better way by an not accident based method (RSI)

12. Research Engineer, PhD Michael Sørensen · Institute of Transport Economics · mis@toi.no · + 47 22 57 39 10 · 23/4-2008 From Black Spots to Grey Road Sections - What is the Right Way? …Questions and comments