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onceptual Frameworks for Developing andomparing Approaches to Improve Adolescentotor-Vehicle Safety

arol W. Runyan, PhD, Michael Yonas, DrPH

bstract: This paper presents practical frameworks for developing and comparing approaches toimprove adolescent motor-vehicle safety by merging concepts from the fields of develop-mental psychology and injury prevention and combining these with elements of apolicy-analysis approach. Together, these models offer conceptual foundations for identi-fying intervention strategies to prevent crashes, reduce injuries in crashes, and reduce thelong-term consequences of crashes and crash-related injury. In addition to helpinggenerate ideas for interventions, the model can be used for making decisions aboutalternative interventions through consideration of value criteria such as effectiveness, cost,freedom, equity, stigmatization, preferences, and both technologic and political feasibility.

Using these models, multidisciplinary groups concerned with youth development, engineer-ing, law enforcement, education, and policy development can find common ground in addressingthe complex issue of teen driving safety and develop, in a systematic and rational manner,approaches tailored to the circumstances and values of the settings in which they work.(Am J Prev Med 2008;35(3S):S336 –S342) © 2008 American Journal of Preventive Medicine

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A police report says the adolescent lost control ofthe car, skidded off the road and slammed into atree. The driver and two other teens were seri-ously hurt. The father of young Alex said policetold him speed was a factor . . .1

An Arlington resident died Saturday, hoursafter the vehicle the teens and several compan-ions were riding in crashed into a wall barrier onTexas 360, police said.2

The victims included the driver [name], 18,who was . . . pronounced dead on arrival at thehospital . . . . Passengers . . . were hospitalized andtreated for injuries. [Name] was in critical condi-tion Friday morning with head injuries and on aventilator . . . . Alcohol was a contributing factorin the crash, police said.3

he specifics of these incidents, all reported inJune 2007, demonstrate the diversity of circum-stances o f adolescent motor-vehicle crashes.

otor-vehicle crashes are the greatest threat to theealth and well-being of U.S. adolescents, accounting

rom the University of North Carolina Injury Prevention Researchenter and Department of Health Behavior and Health EducationRunyan and Yonas), and Department of Pediatrics (Runyan), Uni-ersity of North Carolina at Chapel Hill, Chapel Hill, North Carolina

Address correspondence and reprint requests to: Carol W. Runyan,hD, Injury Prevention Research Center, University of North Caro-

eina, Bank of America Suite 500, Chapel Hill NC 27599-7505. E-mail:runyan@email.unc.edu.

336 Am J Prev Med 2008;35(3S)© 2008 American Journal of Preventive Medicine • Publish

or 38% of all deaths among youth aged 16 to 19 years.4

n 2004, nearly 5000 adolescents in this a g e group diedf injuries in motor-vehicle crashes,4 and adolescentsged 16 –19 were four times more likely than olderrivers to be involved in a crash.5 In addition, theresence of other adolescent passengers increases

he crash risk of unsupervised adolescent drivers, andhe risk increases significantly with the number ofdolescent passengers.6

The magnitude and diversity of the adolescentotor-vehicle injury problem call for a comprehensive

ange of approaches. The recent report of the Institutef Medicine (IOM) Program Committee on Contribu-ions from the Behavioral and Social Sciences in Reduc-ng and Preventing Teen Motor Crashes7 approachedhe issue of adolescent motor-vehicle crashes by inte-rating public health, engineering, and developmentalerspectives. The intent of this article is to presentonceptual frameworks compatible with an integrationf the varied perspectives presented by the IOM report,ith the aim of helping scholars and practitionersrganize evidence and promote new ideas about inter-entions to reduce the risks associated with adolescentriving.As with any public health problem, motor-vehicle

rashes among adolescents can be conceptualized us-ng the social– ecologic framework. This framework,riginally articulated by developmental psychologistrie Bronfenbrenner, describes levels of interacting

cologic systems influencing behavior, specifically de-

0749-3797/08/$–see front mattered by Elsevier Inc. doi:10.1016/j.amepre.2008.06.019

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cribing the microsystem, mesosystem, exosystem, andacrosystem.8 The multiple levels of the framework

efer to varied and distinct social systems within the familynd broader contexts, including the overall culture, inhich children develop. Others have redefined the frame-ork in terms more familiar to the public health commu-ity to encompass the individual, interpersonal relation-hips, organizational and institutional factors, and broaderociocultural characteristics.9,10 The model, shown in Fig-re 1, incorporates the agent–host–environment modelf public health, sometimes referred to as the infectiousisease model.11

Further, injury control pioneer William Haddoneveloped a flexible and practical model for conceptual-

zing interventions specifically to address injury-relatedroblems. Although not directly derived from theocial–ecologic framework per se, the original Haddonodel (Figure 2) is compatible with the framework and

s a straightforward organizing tool for generatingntervention and prevention ideas.11,12 A third dimen-ion (Figure 3) provides an additional perspectiveseful for assisting program planners and preventionpecialists through the complex process of consideringnd deciding which intervention approaches to apply.13

ocial–Ecologic Framework As Related todolescent Drivingntrapersonal Level

t the foundation of the social–ecologic model (Figure) is the understanding that multiple interacting fac-

igure 1. Integration of public health model with Bronfen-renner’s social–ecologic model (source: Runyan11)

igure 2. Haddon matrix template

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ors influence behaviors and, consequently, health. Theactors are conceptualized within nested levels of influ-nce. The innermost level of the framework, the intrap-rsonal level, involves individual characteristics, includ-ng both biological and behavioral factors. In the casef adolescent driving, individual biologic factors in-lude, for example, visual acuity, coordination in man-ging the car, and impaired judgment or reflexes dueo intoxication. Behavioral factors include decisionrocesses in risky situations, distraction by peers, knowl-dge of driving rules and operation of the vehicle, thebility to interpret and respond appropriately to sen-ory information about potential hazards or roadwayonditions (e.g., responding to a skid on ice), andotivations to drive safely and abide by traffic laws.

nterpersonal Level

he second level of the framework, the interpersonalevel, incorporates factors dealing with how adolescentselate to others. These might include peers, as well asarents, teachers, pedestrians, and/or other drivers.xamples include interactions with parents about rules

or using the family car. Peer relationships may becomefactor with regard to pressure to engage in risky

riving behaviors (e.g., speeding, drinking and driving,acing) or when an adolescent legally obtains a driver’sicense before being ready to drive responsibly, perhapswing to parental desire to do less chauffeuring.

nstitutional Level

he third level described in the social–ecologic frame-ork, the institutional level, is associated with institutionsnd organizations with which a person affiliates or byhich the person is influenced. In the case of adoles-ents, these might include schools or related activitiese.g., sports teams, social clubs), churches, and employ-rs, as well as other community-based youth organiza-ions (e.g., scouts, after-school programs, volunteerctivities). Examples at this level related to adolescentriving might include school policies about permittingriving to school or during lunch breaks,14 as well asolicies that influence driving behavior and crash oc-urrence. For instance, the availability of school park-ng lots, participation in after-school activities, andpportunities for driver education may affect adoles-

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ent driving behaviors, as would the availability ofransportation for church, school, or other events.imilarly, work schedules and the availability of employ-ent for adolescents in places served by public trans-

ortation may influence the need to drive.

ociocultural Level

t the sociocultural level are factors such as broad socialorms and expectations about driving-related behav-

ors, as well as local and federal policies that influenceriving behaviors.Examples of these factors include speeding laws and

heir enforcement, graduated driver’s licensing lawsGDL), driver education incentives and requirements,rinking age limits, and specific enforcement proce-ures targeting adolescents (e.g., prom-night stops toheck for driving under the influence of alcohol).dditional social and structural efforts at this level may

nclude the conscious design of alternative transportationpportunities aimed at limiting adolescent driving expo-ure, such as making public transportation more acces-ible to adolescents and promoting designated-drivingractices to prevent alcohol-related driving incidents.nderlying the broader social and cultural dynamics ofrevention are the multilevel, multifaceted networks of

ocal, state, and federal law enforcement protocolsesigned to promote adolescent motor-vehicle safety.

addon Model As Related to Adolescent Driving

addon developed his model from the perspective ofublic health, using the model to identify strategies for

ntervening to reduce the likelihood of injury eventsnd injuries.12,15,16 The public health model itself ar-iculates the relationship between the vulnerable hostnd the agent of disease or injury within the environ-ent, as described by Susser.17 Developed largelyithin the context of infectious disease, this formula-

ion identifies the host as the person at risk of experi-ncing a given health problem (e.g., malaria, chicken-

igure 3. Three-dimensional Haddon model (adapted from

ox, measles). In the case of a motor-vehicle crash, the h

338 American Journal of Preventive Medicine, Volume 35, Num

ost is the person experiencing the injury, whetherriver, passenger, or pedestrian. The agent of disease, inhe case of infectious diseases, is the bacterium or virusesponsible for the infection. With respect to injury,addon defined the agent as the energy transferred to

he host in amounts or at rates damaging to the body.12

e noted that different types of energy transfers areesponsible for injury, including transfers of mechani-al energy (e.g., momentum forcing a head into aindshield during a crash), thermal energy (e.g., burnsssociated with fires or scalds), chemical energy (e.g.,nhalation of carbon monoxide or ingestion of poison-us substances), and radiation energy (e.g., sunburn).n either an infectious disease or injury context, theublic health model addresses the various characteris-ics in the physical environment (e.g., buildings, road-ays) as well as the social environment (e.g., norms,ractices, policies, political will). Energy is deliveredither by an inanimate vehicle (e.g., steering wheel) ory an animate vector (e.g., another passenger).Haddon incorporated these factors from the public

ealth model (host, agent, and physical and socialnvironments) into a matrix that, except for the agent,arallels the social–ecologic framework nicely. He usedhe factors, which both influence injury events and cane changed, as the columns of his matrix. Also, hedded rows to depict the timing of interventions andheir effects on the injury process, which he concep-ualized as having pre-crash, crash, and post-crashhases.16 Haddon later employed broader terminologypre-event, event, and post-event) in his model toddress injury causes other than motor-vehicle crashesFigure 2).16

Used effectively as a brainstorming and problem-olving tool, the Haddon matrix can help identify aultitude of ideas for preventive interventions. In

ublic health terms, it is often helpful to employ aentence-completion exercise in which one fills in theactors and phases as follows: “_____ [an idea] is anntervention designed to change _____ [factor] that will

an13)

ave its effect at the time of _____ [phase].”13 For

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xample, airbags are an intervention that change theehicle and have their effects at the time of the crasheven though they are installed in the car at thessembly plant). This idea would be noted in thevehicle” column, “crash” row of the matrix (Figure 2).ikewise, efforts to reduce drunk driving by teaching

ndividuals to select a designated driver is an individualdriver) intervention with effects at the pre-crash phasei.e., preventing crashes) and belongs in the “host”olumn, “pre-crash” row.

ntegrated Model

lthough the Haddon matrix has been widely used bynjury control professionals since it was first developed

ore than three decades ago, social scientists may findmodel that integrates more closely with the social–

cologic framework to be more appealing. In Table 1,e propose such a model. Our integrated model is

imilar to the Haddon matrix but has an additionalolumn for relationships and integrates physical andocial environment features with the different levels ofhe framework. For our adolescent driving example,he relationships column has been split into separateolumns for peers and parents. In addition, instead ofeparate columns for physical and social environments,he integrated model has one column for institutionsnd organizations (third level of the social–ecologicramework) and one for sociocultural practices andorms (fourth level of the framework). Each of these

wo columns is subdivided into sections for interven-ions in the physical and social environments. In thenstitutions column, for example, interventions in thehysical environment include those directed at schoolsnd adolescent employers; interventions in the socialnvironment include the driving-related policies ofchools and workplaces. Similarly, in the socioculturalolumn, physical environment interventions encom-ass efforts to modify roadways, and interventions inhe social environment include strategies such as insur-nce incentives for safe drivers, nighttime curfews fordolescents, and promotion of norms associated withess tolerance of adolescent drinking and driving.

alue Criteria Used in the Hybrid Social–Ecologicaddon Matrix Model

oth the Haddon model as originally conceived andhe version modified to more closely integrate with theocial–ecologic framework provide a mechanism toelp identify and catalog a myriad of interventionossibilities for addressing any type of health problem.owever, the models fall short of helping practitioners

rrive at clear decisions among the varied approachesenerated by using the models. To address this short-

oming, a third dimension can be added which intro- s

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uces a layer of practical considerations to the Haddonodel (Figure 3) to aid planners in a practical way byelping them move from a broad set of ideas to aystematic process of thinking through key values touide decisions.13

This review process, which draws on a policy-analysisrocess,18,19 entails considering what criteria are impor-

ant to a given decision. The choice of criteria will vary,epending on the context and aspect of the problem.or example, planners might want to emphasize differ-nt values for different communities or for new adoles-ent drivers versus older adolescents. First, any practi-ioner is almost always concerned with evaluationbased on sound evidence) of effectiveness (i.e., Does thentervention work?). Of course, quality and type ofvidence available vary, so this judgment is not alwayslear-cut. Sometimes judgments about effectiveness relyn theory about what should work or on experiencehat may not meet the standards of evidence-basedlanning.Second, other criteria might be considered, includ-

ng horizontal and vertical equity.18 Horizontal equityefers to a universal approach. Considering whether anntervention is directed at all adolescent drivers, forxample, is to assess whether it has horizontal equity.ertical equity, in contrast, exists when an intervention

eeks to treat people differently so as to equalize themn terms of risk or opportunity. In regard to risk, one

ight consider whether to focus on higher-risk adoles-ents and impose more strict regulations on them inrder to equalize their risk with that of other adoles-ents. For example, should more stringent GDL restric-ions be pursued for younger drivers or for those whoave already demonstrated more dangerous drivingehavior? In regard to opportunity, practitioners mightonsider an approach that seeks to equalize safetypportunities by ensuring that the best forms ofriver education or technologies to monitor adoles-ent driving are free for those unable to afford them.uch an intervention would demonstrate vertical equityy helping to equalize opportunities for safer drivingmong youth at different economic levels.

Another value that is often considered important inntervention decisions is freedom. Considerations in-lude: Whose freedom is infringed upon, and howuch? Are the freedoms that are limited important?hose freedoms are protected? For example, the issue

f an adolescent’s freedom may arise when introducingandom traffic stops, without probable cause or suspi-ion, on prom nights to identify individuals drivingnder the influence of alcohol. Likewise, equippingars with speed governors (to limit the maximumchievable speed) or satellite tracking systems (to mon-tor automobile movement and speed) could be vieweds limiting freedoms because behaviors are monitored.n the other hand, to the extent that parents use these

trategies rather than restricting vehicle use, adoles-

Am J Prev Med 2008;35(3S) S339

Table 1. Haddon model integrated with the social–ecologic framework: an example applied to teen driving

Phases

Factors

Host

Relationships

Vehicle

Physical and social environments

Peers ParentsInstitutions andorganizations

Sociocultural practicesand norms

Pre-crash phase(Interventionsto reducelikelihood ofcrashoccurring)

y Teach drivingskills to teens

y Reduce useof cellphones

y Reducedrinking anduse of otherdrugs

y Encouragebetter sleephabits

y Encourageactivities that donot requiredriving

y Reduce peeralcohol use

y Foster designateddriver practices

y Support parents forlimiting teen accessto cars

y Train parents instrategies for betterteaching of drivingskills to teens

y Train and prepareparents to identifyrisk-related behaviorsassociated withdriving (e.g., drivingmany friends)

y Vehicles with ignitionlock system hookedto breathalyzer

y Monitoring devices incars to alert teens orparents when teen isdriving recklessly

y Devices in cars toprohibit driving toofast or too close toother vehicles orspecific hazards

Physicaly Locate schools so driving

is not requiredy Provide no student

parking at schools todiscourage driving

y Provide more desirablepublic transport toschool and work

Socialy Teen driver insurance

penaltiesy Laws restricting teen

driving for worky Later start times for

schools

Physicaly Accessible public

transporty Planned communities

with jobs, schools,homes in closeproximity

Socialy GDL laws limiting

driving hoursy Nighttime curfews

Crash phase(Interventionsto reducerisk of injurywhen crashesoccur)

y Encourageuse of seatbelts

y Encourage peersupport for seatbelt use by alloccupants

y Encourage parents tolet teens drive onlyin cars with fullpassive restraintsystems

y Ensure thatmaximum crashprotection is availablein all cars

Physicaly Law enforcement

practices to monitorspeed and traffic density

Socialy Incentives for companies

to produce more crash-worthy cars

y Workplaces employingteens in driving tasksensure that vehicles usedby teen employees aresafe

Physicaly Roadside barriers to

prevent cars fromentering oncomingtraffic or nearbywater, or going overcliffs

Socialy Insurance and tax

incentive to purchasecrash-worthy/readycars

Post-crashphase(Interventionsto reducenegativehealthoutcomes ofcrashes)

y Teach firstaid skills toall teens

y Teach first aidskills to all teens

y Teach first aid andCPR skills to allparents

y Program GPS devicesin cars to signalemergency careproviders directly,after a crash

Physicaly Locate on-call EMS

substations near busyroads, highways, andmain street intersections

Socialy Encourage public

support for use oftrauma-care triage byEMS providers

Physicaly Ensure accessibility to

emergency vehiclesSocialy Universal health

insurance

CPR, cardiopulmonary resuscitation; EMS, emergency medical services; GDL, graduated driver licensing

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ents may view such efforts as enhancements of theirreedom.

The cost of interventions is often important to thosenvolved and can be considered in various ways. Notnly does this criterion relate to how much money is

nvolved, but also to the issue of who bears the cost ofgiven intervention: Car manufacturers? School sys-

ems? Individual families? In addition, it is imperativeo assess and appreciate the cost and implications of notmploying the intervention (e.g., medical care, loss ofifetime earnings).

Stigmatization is often considered important in mak-ng decisions about health issues. Does a given groupe.g., adolescent drivers under a certain age, or thoseith traffic violations who must start the GDL process

rom the beginning) become stigmatized as a result ofhe intervention, and is such stigmatization desirabler undesirable with regard to the particular interven-ion? For example, is the potential stigmatizationssociated with returning to the bottom of the GDLadder a successful motivator to safe driving, or is it tooemoralizing?Preferences of the affected community is another criterion

ften considered in determining intervention ap-roaches. In the case of adolescent driving, this consid-ration might include the preferences of adolescents,s well as parents or the broader community. Amongarents, the preferences of those weary of driving theirdolescents to functions might be balanced by thereferences of those who want to enhance the safety ofheir adolescents. Likewise, the community may preferromoting public transportation over reducing the

egal driving age, whereas adolescents may prefer earlyccess to vehicles and the resulting opportunities toransport friends. The practitioner trying to sorthrough such preferences will need to consider whoseiews carry more weight, while also trying to understandhat those views are and how they relate to the variousptions under consideration.Finally, feasibility, whether technologic or political, is

mportant to consider. Technologic feasibility is con-erned with the ability of proposed technologic solu-ions to be implemented and to work. For example,lobal positioning system (GPS) now makes it feasibleo track automobiles almost anywhere, whereas this wasot possible only a few years ago. The concepts of

easibility and effectiveness are closely related. Al-hough something may be technologically feasible inhe ideal sense, the actual deployment to scale may fallhort of feasibility owing to effectiveness issues in thereal world” implementation of the measure. For in-tance, it may not be feasible to have GPS devicesnstalled and used in all vehicles driven by adolescents.

Political feasibility is concerned with the ability tonact and implement an intervention. This type ofeasibility might, for example, depend on the political

ill to enact new laws or policies (e.g., strengthening

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DL policy or implementing policy to prohibit stu-ents from driving during school lunch time). Oftenreferences and feasibility intersect. If the communityr powerful groups within the population favor an

ntervention, then political feasibility is more likely. Inddition, the term refers to the feasibility of successfullymplementing and enforcing an intervention. For in-tance, is law enforcement able to successfully enforcehe new policies in the community with available re-ources? In this situation, political feasibility and costssues may intersect.

To conclude the review process, each of the criteriaiscussed above needs to be carefully considered andssessed relative to the others. Then the interventionptions under consideration can be assessed in theontext of one another using a weighting process,13

eading to better informed decisions about selecting apecific intervention approach.

iscussion

his article examines the use of the social–ecologicramework as a way to conceptualize adolescent drivingssues and interventions and demonstrates how theramework can be employed, by building on the Had-on model, as a means of developing and considering

ntervention options. In addition, the article describesow to examine specific intervention options relative toey criteria for decision making.We argue that this type of approach provides those

ho address adolescent driving across different disci-lines (developmental, engineering, law enforcement,ducational, and policy development) with a concep-ual tool for considering multiple approaches to theomplex issues related to adolescent driving safety andor thinking through priorities in a systematic manner.

e encourage the use of these frameworks in multidis-iplinary groups where multiple perspectives and dif-erent values can be incorporated into the developmentf effective adolescent driving interventions.

o financial disclosures were reported by the authors of thisaper.

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