research engineer, phd michael sørensen · institute of transport economics · [email protected] · + 47...

Research Engineer, PhD Michael Sørensen · Institute of Transport Economics · [email protected] · + 47 22 57 39 10 · 23/4-2008

From Black Spots to Grey Road Sections

- What is the Right Way?

Michael SørensenResearch Engineer, PhD

Institute of Transport Economics

2Research Engineer, PhD Michael Sørensen · Institute of Transport Economics · [email protected] · + 47 22 57 39 10 · 23/4-2008

Background for presentation

PhD project: Hazardous road sections in rural areasEU project: Black Spot Management and Network Safety Management (RIPCORD)


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 ineffectiveNSM: 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 yearsRSA: Adopted in more and more countries


Objective, focus and methodObjective

– 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


A new Danish method for NSM - Category and severity based identification

RPI:RWACD:AWACD: 4:

Reduction potential indexRecorded accident cost weighted accident densityAverage accident cost weighted accident densityEstimered identification criterion for Denmark

)ACD(W)ACD(W)ACD(W WACD proppropminminserser

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 severityWeight for accidents with different severity


Weights

Accident costsAC ser = (CPkilled ∙ xkilled) + (CPser ∙ xser) + (CPmin ∙ xmin) + CPracc

ACmin = (ACmin ∙ xmin) + CPracc

ACprop = CPracc

Costs related to people and property damageCPkilled = 10,404,000 DkkCPser = 1,085,000 DkkCPmin = 295,000 DkkCPracc = 100,000 Dkk

Number of injured road usersxKilled: Killed per accidentxser: Serious injured per accidentxmin: Minor injured per accident

prop

serser AC

ACW

prop

minmin AC

ACW 1

AC

ACW

prop

propprop


Identification - an exampleRingkøbing County and

Viborg County1.561 km290 sectionsAverage length: 5,4 km18 grey road sectionGrey road sections

comprise 4-8 % of the road network

# #

#

#

###

#

#

#

#

#

##

#

#

#

#

Tarm

Ikast

Kibæk

BrandeSkjern

Struer

Lemvig

Herning

Videbæk

Ulfborg

Vinderup

Harboøre

Thyborøn

Holstebro

Hvidbjerg

Ringkøbing

Hvide Sande

Sønder Felding

Ringkøbing.shpKommuneveje.shpStatsveje.shp

Arp.shpOver 43 - 42 - 30 - 2Under 0

# Byer.shp

Ringkøbing County

# #

#

#

###

#

#

#

#

#

##

#

#

#

#

Tarm

Ikast

Kibæk

BrandeSkjern

Struer

Lemvig

Herning

Videbæk

Ulfborg

Vinderup

Harboøre

Thyborøn

Holstebro

Hvidbjerg

Ringkøbing

Hvide Sande

Sønder Felding

Ringkøbing.shpKommuneveje.shpStatsveje.shp

Arp.shpOver 43 - 42 - 30 - 2Under 0

# Byer.shp


Different identification methods

Reference to population of site

Section length

Reference to normal safety level

Recorded or expected number

Accident severity considered

Accident period

Denmark Yes 2-10 kmYes, Category analysis

RecordedYes, Weights for 4 different categories of accident

5 years

Germany Yes 3-10 kmYes, Category analysis

RecordedYes, Weights for 3 different categories of accident

3 years

Norway Yes1 km (more)

Yes, Accident prediction models

ExpectedYes, Weights for 4 different categories of injured

8 years

USA YesSeveral miles

Yes, Accident prediction models

ExpectedYes, Possible to select the most severe accident

Optionally


NSM compared with RSA, RSI, and BSM

Philo-sophy

Identifi-cation Analysis Severity Length

Frequ-ency When

RSA Proactive New roadsNot accident based

-All new roads

Once0-1 year after opening

RSI ProactiveNot accident based

Not accident based

- 2-10 kmEvery 2-4 year

Over 3-4 years after opening

NSMPro- and reactive

Accident based

Accident based and general problems

Included 2-10 kmEvery 2-4 year

Over 5 years after opening

BSM ReactiveAccident based

Only accident based

Not included

Under0.5 km

Every 1-2 year

Over 5 years after opening


Assessment of method and philosophyAn 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 section A B C D E F G H I Total

Remedial and preventive 7 3 1 3 3 5 2 3 4 31Only preventive 9 11 7 13 5 9 6 5 12 77The nature of measures proposed on 9 grey road sections


Conclusion – NSM is not the wayThe 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)

Research Engineer, PhD Michael Sørensen · Institute of Transport Economics · [email protected] · + 47 22 57 39 10 · 23/4-2008

From Black Spots to Grey Road Sections

- What is the Right Way?

…Questions and comments

research engineer, phd michael sørensen · institute of transport economics · [email protected] · + 47...

Documents