Introduction Describe a systematic process to determine proactive - - PDF document

Justifying Road Safety Investments for Locations Without Collisions By Quantifying Road Safety Risk

Paul de Leur, PhD, P.Eng.

XI ICTCT extra Workshop, Vancouver, Canada, March 2018

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Introduction

• Describe a systematic process to determine

proactive road safety investments

• Implemented in British Columbia by the Insurance

Corporation of BC (ICBC)

• Road Safety in BC

– Land Area: 95,000 km2 – Population: 4.6M – Vehicles: 3.5M – Paved Roads: 25,000 km – Fatal Crashes: 280 per year – Injury Crashes: 13,000 per year

XI ICTCT extra Workshop, Vancouver, Canada, March 2018

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Introduction

• ICBC is a publically run automobile insurance

company in the province

• Because of the public nature of the organization,

ICBC has a mandate to improve road safety

– Also good business, as ICBC is a road safety benefactor (reduced crashes = reduced auto insurance claim costs)

• ICBC’s Road Improvement Program provides funding

to road authorities for safety improvements:

– $180M in road safety funding since inception – Demonstrated effectiveness: >4:1 ROI

XI ICTCT extra Workshop, Vancouver, Canada, March 2018

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Investments in Road Safety

• Important to make wise road safety investment

decisions

– Limited funds available – Maximize impact / effectiveness

• Many road safety investments (infrastructure) are

reactive and made to respond to known safety problems

– a high-crash location

• Objective: reduce frequency / severity of collisions

XI ICTCT extra Workshop, Vancouver, Canada, March 2018

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Investments in Road Safety

• Although effective & necessary, reactive road safety

investments can be limiting

– No investment at locations that are high-risk, but do NOT have a significant history of collisions – Decisions are based on collision data, which can suffer from quality and quantity issues – Difficult to justify investments in VRU interventions due to lack of collision clustering – May not support the need for regional equity wrt the funding that is available for road safety investments

XI ICTCT extra Workshop, Vancouver, Canada, March 2018

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Investments in Road Safety

• Recognizing a need to target high-risk, low crash

locations, ICBC’s Road Improvement Program (RIP) developed a process to proactively assess locations and justify road safety investments

– The “Proactive Road Safety Program” allows for up to 25%

• f the total road safety investments to be allocated to

‘proactive’ projects – The program objective is to prevent collisions rather than reduce collisions

XI ICTCT extra Workshop, Vancouver, Canada, March 2018

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Road Safety Risk

• Approach based on the identification, understanding

and quantification of road safety risk

XI ICTCT extra Workshop, Vancouver, Canada, March 2018

– Road safety risks are not always evident to the driver – The magnitude of road safety risk is not always clear

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Road Safety Risk

• There are some existing techniques that are available

to evaluate road safety risk

• Traffic Conflict Technique: A technique that is based
• n the concept of near-misses and evasive

manoeuvres

– Time to Collision / Risk of Collisions

• Road Assessment Programs (RAP): Uses a star-rating

system based on roadway characteristics that impact safety performance

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Road Safety Risk

• For our approach, we describe road safety risk as a

function of three fundamental elements:

– 1) Exposure: the exposure to roadway hazards

• Traffic or road user volumes, V/C ratio, etc.

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Road Safety Risk

• Road safety risk is expressed as a function of three

fundamental elements:

– 2) Probability: probability of encountering roadway hazards

• H/V alignment, cross-section, access density, conflict potential, etc.

XI ICTCT extra Workshop, Vancouver, Canada, March 2018

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Road Safety Risk

• Road safety risk is expressed as a function of three

fundamental elements:

– 3) Consequence: severity of outcome if hazard encountered

• Vehicle speed, roadside environment, etc.

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Road Safety Risk

• Developed procedures to quantify each element of

road safety risk

• Three risk elements are combined to produce an
• verall level of risk

– Road Safety Risk Index (RSRI) – Represents a measure of risk and is independent from historical collision records

XI ICTCT extra Workshop, Vancouver, Canada, March 2018

RSRICombined= Ei+P

i+Ci i =1 n

∑

9(n)

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Effectiveness of Interventions

• With RSRI determined, the next step is to evaluate

the effectiveness of the proposed interventions

– Interventions have varying levels of effectiveness – More effective interventions should be eligible for a higher level of road safety investment

XI ICTCT extra Workshop, Vancouver, Canada, March 2018

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Effectiveness of Interventions

• Collision modification factors (CMFs) used to evaluate

intervention effectiveness

– CMFs for BC – CMF Clearinghouse – AASHTO Highway Safety Manual – Elvik & Vaa

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Evaluate Road Safety Investment

• RSRI is combined with the CMF to produce a

‘Proactive Funding Index’ (PFI)

• Level of ICBC

funding based on an exponential function benefiting projects with a higher PFI

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Summary

• It is important to address known safety problems

– Reactive interventions are effective to reduce collisions at collision ‘hot-spots’

• Also possible to make proactive road safety

investments

– Proactive interventions to prevent collisions at high-risk locations

• Proactive interventions have greater ability to focus
• n the needs of VRUs

XI ICTCT extra Workshop, Vancouver, Canada, March 2018