Targeting high risk groups of drivers
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Targeting high-risk groups of drivers. Adolescent drivers and elderly drivers. Drivers killed/injured pr. million km driven. Bjørnskau, 2004. Proportion of drivers 65 year of age and older with a driver license – 1980-2002 (Norway). Characteristics of accidents with older drivers.

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Targeting high-risk groups of drivers

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Targeting high-risk groups of drivers

Adolescent drivers and elderly drivers

Drivers killed/injured pr. million km driven

Bjørnskau, 2004

Proportion of drivers 65 year of age and older with a driver license – 1980-2002 (Norway)

Characteristics of accidents with older drivers

  • Overrrepresented in junction accidents, especially when turning left (in countries with right-side driving).

  • Higher accident risk in roundabouts

  • Overrepresented in wrong-way driving accidents

  • Elderly have problems reading signs on distance, especially at nighttime and under glare conditions

  • Signs often have too short sight distance to have enough time to perceive and react

Characteristics of older drivers – age related changes:

  • Visual and auditory functions impaired

  • Cognitive ability can be impaired – e.g. reduced perception, attention and information processing

  • Physical ability reduced (stiffer neck, torso, reduced muscle power)

  • More health problems and more use of medication

  • However – large in-group variation – an older driver is not necessary a bad driver

On the other hand, elderly drivers:

  • are usually very safety oriented (few violations)

  • have a defensive driving style

  • tend to compensate for their impairments by:

    • avoiding heavy traffic

    • driving at night-time/evening

    • avoiding driving on slippery roads and during difficult weather conditions

    • using passengers as “co-pilots”

  • Many elderly drivers may therefore be the safest drivers

  • Reason to believe that certain subgroups of elderly drivers accounts for the increase in risk

Subgroups with functional impairments -vision

  • Weak association between visual acuity (synsskarphet) and accident risk

    • Due to compensation?

  • Reduced visual acuity under glare conditions associated with a poor driving performance (indikasjon på grå stær/cataract)

  • Defects in the central field of view also associated with poor driving performance

  • Neither of these two tests are included in the medical test older drivers have to pass today

Ulleberg og Sagberg, 2003

Reduced acuity under glare conditions

Defects in the central field of vision may impair perception

Moderate defect

Severe defect (extreme example)

Amsler grid – indication of defects in the central field of view

  • Focus on the dot in the middle

  • Breaks/waves in the grid indicate defects in the central field og vision

Attention and accident risk are related

  • UFOV (”useful field of view”)

    • Slow information processing

    • Impaired divided and selective attention

    • Low capacity of using information in the peripheral field of view.

  • Other cognitive impairments typical for dementia related to accident risk

    • Short time memory, spatial orientation, change of attention and being able to concentrate over time

Reduce mental workload and (consequenses) of driver error

Reduce injury if an accident occurs

The vehicle


Reduce mental workload and driver errors

Improve functional ability

The road infrastructure

The driver

Reduce injury for drivers, pedestrians and cyclists


Holistic approach to safety promotion for older drivers

Examples of road design for elderly drivers

  • The system is today primarily designed for the young and healthy driver

  • A road system designed for the older driver may improve safety for all drivers

Example – Avoidance of junction accidents

Main idea: lowering information processing demands (less mental workload)

  • simplify junctions (e.g. from X- to T-crossing)

  • left-turn lane and own signal-light phases for left turns

  • road illumination at junctions and pedestrian crossings

  • increase size and conspicuity of signs and other information

  • Increase time from information is presented to the driver has to respond (more than 2.0 sec)

Example: wrong way driving on motorway


Correct direction

Planned direction

Wrong way!

Several factors complicating the information processing at Hvam

  • Several roundabouts near each other

  • Information overload concerning signs

  • Contra-intuitive direction of on-ramp (more natural to believe that the wrong ramp is the correct one)

  • On-ramp placed in connection to roundabout

  • All these elements should be avoided

Typical driver error resulting in wrong way driving from service areas

Gas station

Better solution?

  • Simplify the driver’s decision making

Curve signal that this is an unnatural way to enter

Avoiding errors and reducing injury through special vehicle design for older drivers

  • Several types of equipment may reduce workload and help reduced motoric skills

    • Existing: Power steering, power brakes, automatic gearing

    • Soon to come: night-time vision, collision avoidance systems (but uncertain effect)

    • Several passive safety measures are today unsuited due to higher fragility among elderly drivers: airbags too powerful, seat belts may cause injury

More errors and slips/lapses?

inexperienced, driving skills are not automatized

low spare mental capacity when driving

hazards not perceived adequately

More violations?

- ”Poorer” attitudes

More preferences towards risk-taking?

More social pressure towards risk-taking?

Possible explanations for young drivers elevated accident risk

The answer seems to be ”yes” to both explanations

The accident risk is reduced by 50 % during the first 9 months

Sagberg, 2002

Same tendency for all age groups


Experience, less errors?

Maycock, 1991

What happens during the first nine months?

  • Routine behaviours get automatised(are performed without conscious attention)

  • Increased spare mental capacity for handling unexpected events

  • Consequences: Technical skills improve, fewer slips & lapses and errors

  • Hazard perception improves (faster & better)

Sagberg og Bjørnskau, 2003

  • Also: Learning to interact better with other drivers – being more predictable for others

  • Interestingly: more violations (!), especially running yellow lights, more “offensive” driving like less hesitation at junctions etc.

The experience paradox

  • Most important experience must be gained during the most dangerous period of a driver’s development (i.e. first year holding a driver license)

  • How can this experience be gained in a safe way?

Driving with a lay instructor and accident risk after licensing

Sagberg, 2002

  • However – even though the accident risk is reduced after nine months, it is still high compared to more experienced drivers

  • Due to risk-taking? Safety motivation needs to be addressed

Improved skills and lowered safety motivation



Summala, 1996

Not all young drivers are high-violators

Ulleberg, 2002

Cluster 2

Cluster 5

Low anxiety

High anxiety


High aggression


Mild social deviance

High sensation seeking


Personality traits and driver behaviour

Two ”problem groups” of young drivers

Ulleberg, 2002

Response to a traffic safety campaign by cluster

Ulleberg, 2002

Why are risk-takers so difficult to influence?

Rejection - does not elaborate the message

  • Affect and hedonism – does not like the message, too much in conflict with own preferences – the processes of contrasting and rejection

    • No personal relevance - No.1 attitude: ”I have such good driving skills that I can take more chances than others” (meaning: the message does not apply to me)

    • Low preferences for elaborating messages in general (are they bit stupid…?)

      Reckless driving seems to be a very important part of their identity (and reflection of their personality). Difficult to change people’s lifestyle through an attitude campaign

Influencing adolescents through campaigns

  • Advantageous to let adolescents perceive that they themselves take decisions about attitude/behavioural change. Do not tell them directly how to think and behave!

  • Self-initiated decisions usually motivate for deeper elaboration of the message, which may facilitate attitude/behaviour change

  • Adolescents are more easily influenced by social and group pressure. Face-to-face communication most efficient. Especially from other adolescents

  • New campaigns tries to motivate adolescents to influence each other – e.g. passengers influencing the driver. E.g. “Sei I frå!” campaign

  • Targeting night-time weekend driving and group pressure may be especially relevant

Risk of injury by time and day

Bjørnskau, 2004

Reducing exposure at night-time in weekends especially relevant

Increase in accident risk when young drivers carry young passengers

Chen, 2000

Focus on positiv guidance from passengers, reduce group pressure especially relevant

Other possible measures

  • Restriction of night-time driving and carrying young passengers for young drivers (implemented in several countries)

  • Alternative modes of transport more easily available (e.g. cheap taxis during weekends)

  • More driving at motor sport lanes? Supposed catharsis-effect, but may have the opposite effect on safety due to compensation (increased belief in own driving skills)

Model illustrating factors influencing young drivers driving behaviour and accident involvement

Decision making



Driving behaviour:

Slips and lapses



Automatization of the driving process

Driver education



Actual driving skills

Perceived driving skills


Perceived risk of accidents



Group norms

Cognitive and motoric skills



influence and individual differences

Modified model based on Gregersen og Berg, 1996

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