Towards a safe system Letty Aarts September Long term safety in traffic Letty Aarts SWOV Institute for Road Safety Research the Netherlands

Towards a safe system Letty Aarts September Traffic safety in the Netherlands Our safety ‘landscape’ over years… International top position

Towards a safe system Letty Aarts September Safe system approach in the Netherlands: Sustainable Safety Aims  Prevention of serious crashes  Reduction of probability of severe injury when a crash occurs Copies free downloadable from

Towards a safe system Letty Aarts September How well is your policy tuned to human nature? We all make errors We do not always obey rules

Towards a safe system Letty Aarts September Causes of crashes and a safe system approach Human: % Vehicle: 4-25% Infrastructure: 12-46% Integral approach of …  Vehicle  Man  Infrastructure

Towards a safe system Letty Aarts September Proactive system approach (after Reason) System design Quality control Psychological precursors for unsafe actions Actions during traffic participation Defence mechanisms Latent errors CRASH Unsafe actions

Towards a safe system Letty Aarts September Proactive system approach (after Reason) System design Quality control Psychological precursors for unsafe actions Actions during traffic participation Defence mechanisms Unsafe actions Latent errors

Towards a safe system Letty Aarts September Classifications of human failures Unsafe actions

Towards a safe system Letty Aarts September Classifications of human failures Unsafe actions Judicial classification Violation

Towards a safe system Letty Aarts September Classifications of human failures Unsafe actions Unintended action Intended action Slip Mistake Violation Lapse Errors Psychologic classificationJudicial classification Violation

Towards a safe system Letty Aarts September Reasons for (judicial) violations and conformity BehaviourCause of violationCause of conformity Intentional Perceived costs < benefits Feeling of comfort Incredible rules Indifferent environment Normative viewpoint Perceived costs > benefits Fear of punishment Unintentional Imitating incorrect behaviour of others Incorrect habits System invites correct behaviour Road layout Vehicle Behaviour of others Road layout and vehicle provoke incorrect behaviour Error

Towards a safe system Letty Aarts September Effects of enforcement (after Elvik)

Towards a safe system Letty Aarts September How does enforcement work?

Towards a safe system Letty Aarts September How does enforcement fit into a safe system approach? General deterrence  Subjective enforcement pressure  Objective enforcement pressure  Credible enforcement communication  Threat of sanctions Specific deterrence  Being caught  Objective enforcement pressure  Effect of sanction  Effect of treatment on the spot (?)

Towards a safe system Letty Aarts September Deterrence: theory and practice Perspectives  Instrumental: conditioning of behaviour  Normative: information and public acceptance Policy  Financial penalty  Demerit-point system  Licence withdrawal after serious violation  Rewarding and treatment on the spot  Smart key or lock Effects?  Depends on probability of getting caught!  Larger effect with instantanious sanctions (efficiency?)  Combination of reward and punishment: large effects

Towards a safe system Letty Aarts September The human measure… but are all drivers similar?

Towards a safe system Letty Aarts September Can we distinguish different groups? ‘Normal’ offenders Heavy offenders Recidivists

Towards a safe system Letty Aarts September Preventing violations in a safe system Better safe than sorry: large scale prevention  General implementation of locks  General deterrence  General public acceptance  Use evidence-based methods Specific approach: heavy offenders  Use intelligence and evidence-based methods Let general deterrence or prevention not suffer from effort needed for catching hard offenders! So:  Put personal effort in hard offenders  Make general deterrence or prevention effective and efficient

Towards a safe system Letty Aarts September To conclude Safe system approach  Man as measure of al things  Focus on prevention  Improvements of the integral system  Better effects  More public support (credibility) Safe system enforcement  For most road users:  General deterrence > specific deterrence  Prevention within the system > deterrence  Specific intelligence actions for catching heavy offenders: After an increase in ‘quantity’, we need an increase in ‘quality’!