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Road Traffic Injuries: A Global Epidemic
Lauren P. Giles, B.A., Elisabeth S. Hayes, M.B.A., and Mark L. Rosenberg, M.D., M.P.P.

Dr. Rosenberg is Executive Director of the Task Force for Child Survival and Development. Ms. Giles and Ms. Hayes are, respectively, Program Development Coordinator and Senior Program Associate for the Global Road Safety Program at the Task Force. The Task Force for Child Survival and Development is an independent non-profit organization affiliated with Emory University, Atlanta, Georgia.

The authors report no commercial conflict of interest.

Release Date: 05/23/2005
Termination Date: 05/23/2008

Estimated time to complete: 1 hour(s).

Albert Einstein College of Medicine designates this enduring material for a maximum of 1.0 AMA PRA Category 1 Credit(s)™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Albert Einstein College of Medicine is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.
Learning Objectives
Upon completion of this Cyberounds®, you should be able to:
  • Describe the worldwide road safety epidemic in terms of its human and economic tolls, as well as its impact on global social equity
  • Describe the roles of the driver, vehicle and built environment in road safety
  • Define populations at high risk for road traffic injuries
  • Describe the major factors influencing road crash involvement and crash severity, and key interventions to reduce crash risk.


There is a hidden epidemic on the world's roadways. Over one million people every year are killed in road crashes, and 20-50 million are injured. Still, road traffic safety receives little international attention, and few are aware of the human and economic toll of road crashes on low- and middle-income countries, which represent 85% of deaths and the lion's share of injuries. As developing-country vehicle use rises, road traffic injuries (RTIs) are also growing. By 2020, RTIs are expected to be the third leading cause of death and disability worldwide, by some calculations matching the toll of AIDS.(1),(2),(3),(4),(5)

For every RTI death, there are four cases of severe, permanent disabilities, typically to the brain, spinal cord or lower limb joints; 10 cases requiring hospital admission and 30 requiring treatment in an ER. In the European Union alone, 150 000 people are left permanently disabled by RTIs each year.(6) Crash victims are often working-age adults, whose families are left without a primary source of financial support. A study in Bangladesh found that 70% of families experienced a decline in household income and food consumption after a road death.(7) Victims and their family members frequently experience depression, travel-related anxiety and sleep disturbance for years after a crash.

The direct global cost of road traffic crashes is over US$500 billion annually, while the cost to developing nations is estimated at US$65 billion, almost double the total amount of development assistance sent to such nations every year.(2) Indirect costs to victims, families and governments -- such as potential income and societal contributions lost -- are not included in these calculations. The average impact of crash costs on low- and middle-income countries has been estimated at 1-1.5% of GDP.(2) Road traffic injuries are a global epidemic and the situation is only getting worse.

More Than 'Being Careful': Understanding Road Crash Prevention

For years, the understanding was that responsibility for preventing traffic injuries lay with road users: drivers, pedestrians and cyclists. Crashes were considered to be random events and being careful was the best way to avoid them. In the United States, this conception began to shift in the 1960s with the publication of Ralph Nader's Unsafe at Any Speed, which detailed risks to passengers from poor vehicle design and the reluctance of automakers to include crash-protective features. The US Congress responded to this and other criticisms by passing the 1966 Highway Safety Act, which created the National Highway Traffic Safety Bureau (now Administration or NHTSA).

The Highway Safety Act represented the first nationwide legislative effort to reduce crashes, and included provisions on road improvements, hazard removal and vehicle safety, taking the focus off the driver as the primary cause of crashes. In the succeeding decades, NHTSA invested in research that contributed directly to making safer cars, safer roadways and safer drivers. In many developing countries, however, road crashes are still seen as 'accidents' that cannot be prevented.

In fact, road crashes are both predictable and preventable. The causes of RTIs have been established: excessive speed, consumption of drugs and alcohol, failure to use protective measures such as seatbelt and helmets, poor vehicle impact protection and poor road design. At-risk populations have been defined. Proven, cost-effective prevention measures exist. The real barrier to reducing road traffic injuries is fatalism -- accepting road traffic injuries as inevitable, as the necessary cost of development, keeps us from addressing this devastating epidemic.

The Road Traffic Safety System

To understand road crash prevention, it is necessary to view the road user, the vehicle and the built environment as elements of a dynamic system that work together to either produce or prevent injuries. Road users include drivers or occupants of buses, trucks and passenger cars, riders on motorized two-wheelers (MTWs), cyclists and pedestrians. Pedestrians, cyclists, bus passengers and MTW riders are called 'vulnerable' road users because they are at greater risk of injury or death if involved in a collision. Vehicles can be either motorized (cars, trucks, two- and three-wheelers) or non-motorized (bicycles, carts, rickshaws). The road environment varies by road location (rural or urban), type of road (motorway or street), time of day, visibility and traffic flow.

It is also critical to appreciate the three phases of injury as applied to road safety -- pre-crash, crash and post-crash. In the pre-crash phase, preventive measures may be taken, such as enforcement of drunk-driving laws and the separation of pedestrians from vehicles. During a crash, forgiving roadway designs and vehicle safety features can reduce injuries. In the post-crash phase, acute care, rehabilitation and long-term care are critical. Healthcare professionals play a vital role in helping crash victims to recover from their injuries and return to their lives.

Effective interventions must address the entire road system. Programs to teach children to look both ways before crossing the street will prevent a limited number of injuries, but if we provide sidewalks and speed bumps, mandate safer vehicle fronts and enforce speed limits, many children will be saved from death or lifelong disability. Encouraging safe behavior among road users is important but it is not enough to stop the road traffic injury epidemic.

Vulnerable Road Users Are the At-Risk in Low- and Middle Income-Countries

Developing Countries

Residents of developing countries are at much higher risk of RTIs than are residents of high-income countries. They are also at greater risk of death when a crash occurs: in the US, 10,000 crashes result in 66 deaths but in Vietnam, for example, there are 3000 deaths per 10,000 crashes.(8) Rapid motorization, which often accompanies rapid economic development, has long been understood to lead to higher RTI risk,(9) because of its adverse impact on the three components of the road system:

  • There are greater populations of vulnerable road users in motorizing nations than in higher-income countries. In many developing nations, though vehicle use has skyrocketed, the vast majority of people still walk or bicycle to work. Those traveling in motorized vehicles are often bus passengers or motorized two-wheeler riders.
  • Vehicles are less safe in developing nations. Buses are often second-hand imports from wealthier countries and lack up-to-date safety features. Passenger cars tend to be older and do not have air bags, collapsible steering columns or other crash-protective features. In addition, vehicles are not as well maintained in developing countries.
  • Poor road and land-use planning often leads to a deadly mix of high-speed through traffic, heavy commercial vehicles, MTWs, pedestrians and bicyclists on developing-country roads. Accommodations for vulnerable road users, such as sidewalks and bicycle lanes, are rare.

Developing countries also have inadequate trauma systems and are often unable to care for crash victims. Unless action is taken to improve road safety systems, poor countries will continue to bear the heavy toll of road traffic injuries.

Pedestrians and Cyclists

Pedestrians and cyclists incur higher crash risks than other road users. The modern traffic system, in both the developed and developing worlds, is designed primarily for motorized vehicles and often fails to make provision for other road users.

Young Drivers and Men

Young drivers and riders, particularly males, are at higher risk for crash involvement. Teenage drivers run the greatest risk of any age group, particularly within the first year after receiving a full license. Men, especially young men, are more likely than women to be in a road crash.(10)

Taking Action on Road Safety: Key Steps for National Governments

Acceptance of a high rate of RTIs continues in part because no one is responsible for lowering the crash rate. A critical first step is the appointment or creation of an agency to lead the national road safety movement. A lead agency, once appointed, creates needed focus and accountability for road safety.

Specific interventions will vary by country and within countries. Governments must assess the road safety problem in their country and prepare a national strategy that incorporates those steps most likely to have an impact on RTIs. National plans should set clear, measurable goals and provide for evaluation of outcomes. Plans must also address all three phases of road traffic injuries: prevention, minimization, and post-crash and long-term care.

Specific Interventions

Below, we discuss the major factors that influence crash involvement and crash severity, as well as proven, cost-effective interventions that governments can adopt to reduce RTIs. This is not an exhaustive list, and there are many risk factors (cell phone use, driver fatigue) and interventions (red light enforcement, use of crash cushions) not discussed here. Study and research are vital to determine local needs and appropriate measures. However, one or more of the following factors are implicated in the vast majority of road crashes.

Environmental Factors

Safety is often left out of the road planning and construction process. This is a particular problem in developing nations, who spend very little on road safety. For every $2500 the Asian Development Bank spends on transport projects, only $1 or less is spent on safety initiatives.(11)

The separation of different types of road users is a key step for improving safety. Crashes will be reduced if we keep pedestrians and cyclists off motorways, create bicycle lanes, provide sidewalks and put safety barriers between pedestrian zones and the roadway. Road planners should also seek to keep high-speed traffic and heavy commercial traffic separate from lower-speed, inner-city traffic.

Vehicles leaving the road and colliding with solid objects are a major safety problem. Researchers in Australia and the EU have found that such collisions are involved in 18-42% of fatal crashes.(12),(13) Reduced visibility resulting from hedges, signs and poles is also a safety concern. Removal of unforgiving objects and keeping lines of sight clear will reduce these risks.

Vehicle Factors

Design features can reduce both crash risk and crash severity. Use of daytime running lights for motorized vehicles and reflectors for bicycles improves visibility. "Smart" features can discourage speeding, remind drivers to use seatbelts, improve vehicle stability and prevent a drunk driver from turning on a car. Airbags, collapsible steering columns and rollover protection can reduce the severity of injuries sustained in a crash. Unfortunately, vehicles in developing countries are often older and lack up-to-date crash-protective features and "smart" systems are expensive or unavailable. Developing countries need to establish higher vehicle safety standards that, in turn, could help increase the prevalence of modern safety features in developing-country vehicle fleets.

Driver Factors

Speeding dramatically increases crash risk and crash severity. It has been shown that an increase of 1 kph in mean traffic speed results in a 3% increase in the incidence of injury crashes and a 4-5% increase in fatal crashes.(14) Passengers in a car with an impact speed of 80 kph are twenty times more likely to die than at an impact speed of 32 kph.(15) While 90% of pedestrians involved in a crash at 30 kph or slower will survive, at speeds over 45 kph, chance of survival drops below 50%.(16),(17) Lowering the speed limit can dramatically impact fatality rates: a 20 km/h decrease in the speed limit on Swedish motorways, for example, led to a 21% drop in RTI fatalities.(18) Enforcement of set speed limits through radar guns and police presence has been shown to lower crash deaths by 14% and injuries by 6%.(19) The well-publicized use of speed cameras has also been shown to reduce crashes substantially.(20),(21),(22)

As blood-alcohol content (BAC) increases, risk of crash involvement rises dramatically. Crash risk at a BAC of 0.05 g/dl, a common legal limit in the United States, is already 1.83 greater than at zero BAC.(23) While the danger of drunk drivers to pedestrians is well known, pedestrians' own consumption of alcohol significantly increases risk of dying in a crash.(24)

The introduction of BAC limits is associated with a decrease in alcohol-related crashes, and subsequent lowering of such limits leads to further reductions, though the magnitude of such effects varies widely. The most effective way to deter drunk driving is to raise drivers' perceived risk of getting caught.(25) Sobriety checkpoints and random breath testing have been found to lower alcohol-related crashes by about 20%.(26)

Seatbelts and Child Restraints
Failure to use seatbelts and child restraints dramatically increases crash severity. Seatbelt use reduces crash death risk by 40-65%, moderate and severe injuries by 43-65% and all injuries from 40-50%.(27),(28) Use of child restraints has been shown to reduce infant crash deaths by about 71% and small children's deaths by 54%.(29)

Seat belt laws have saved many lives. Visible, well-publicized enforcement programs can increase seat belt use by 10-15% over usage rate at program initiation.(30) In the United States, mandatory child restraint laws were found to reduce fatal injuries by 35% and increase restraint usage by 13% on average.(31),(32) Unfortunately, use of seat belts and child restraints are still not mandatory in many low-income countries.

Head trauma is the major cause of hospital admissions and deaths among riders of motorized two-wheelers and bicycles.(33),(34) Among motorized two-wheeler riders, it has been found that in a crash, users without helmets are three times more likely to sustain head trauma than are helmeted users.(35) Bicycle helmet use reduces head injury risk from 63-88%.(36),(37),(38)

Mandatory helmet laws reduce head injuries among cyclists by about 25%.(19) Thailand's enforcement of a mandatory helmet law for motorcyclists was associated with a sharp increase in use and a 41.4% decrease in head injuries among MTW riders.(39) Unfortunately, rates of helmet use vary widely, dependent on the existence or enforcement of helmet laws.

Physicians and Road Safety

Medical professionals play a key role in their clinical practice in promoting safety on the road. Taking alcohol and drug histories during routine office visits enables doctors to flag substance abuse problems and educate patients about the associated risks. ER physicians can test crash victims for drug and alcohol use and refer those testing positive for treatment, though reporting test results to law enforcement is discouraged because of issues of confidentiality.

Pediatricians can educate patients and their parents about bicycle helmet use, use of child seats and booster seats and safety when walking to school or riding the school bus. They can also advocate for increasing parental involvement in their children's driving, and advocate for graduated licensure. Hospitals can create a coordinator responsible for ensuring that newborns are only discharged to parents who have an approved, properly fitted car seat, and can connect needy families with organizations that provide such seats free or at reduced cost.

Physicians can also make patients aware of when they shouldn't drive, whether because of side-effects of prescription drugs, diminished vision, hearing or coordination associated with a condition under treatment or the results of aging. The National Highway Traffic Safety Administration and many US professional associations, including the American Medical Association, American College of Emergency Physicians and American Academy of Pediatrics provide guidance to physicians for promoting road safety in their practices.(40)

Case Studies of Successful Road Traffic Safety Interventions in Low- and Middle-Income Countries

Costa Rica(41)

The Problem
Costa Rica is a small Central American nation with a vehicle fleet of around 900,000. Road traffic injuries are a major public health problem: they are the leading cause of violent deaths, the leading cause of death in the 10-45 years age group and the third leading cause of years of life lost from premature death. About 600 people die from RTIs annually and many more are injured. The cost of crashes amounts to almost 2.3% of GDP.

A National Problem
In 2001, Costa Rica set a goal of a 19% reduction in traffic fatalities in the period 2001-2005. The Costa Rican government sought the assistance of the government of Sweden, the FIA Foundation and the Global Road Safety Partnership in the development and implementation of a national road safety plan. Drunk driving and seatbelt non-use were targeted as key factors in crashes and crash severity. An existing national agency, the National Highway Safety Council, was charged with coordinating the effort.

Legal reforms have strengthened protection of pedestrians and made seat belt use compulsory. The Costa Rican government has taken steps to improve the road environment, including construction of pedestrian bridges and walkways and installation of new lights and signs. Police enforcement of seatbelt, speeding and drunk driving laws has been stepped up, and police presence on the roadways at night and during special events has been increased. National ad campaigns promote safe behavior and road safety education has been added to primary and secondary school curricula.

Data on road crashes are being compiled systematically and made available to the public through the website of the National Road Safety Council. Studies on risk factors, crash victims and the economic impact of RTIs, among other topics, are underway. Recent data show an 11% decline in number of crashes and a 16% drop in fatalities since the beginning of 2003.

Bogota, Colombia(42)

The Problem
Bogota, the capital of Colombia, is a city of seven million. In 1995, nearly 1,400 people died as a result of RTIs. The municipal government decided that urgent action was necessary to reduce crash rates.

The Bogota government, along with the national Transportation Ministry and the National Fund for Road Accident Prevention, adopted a comprehensive and creative approach to RTI prevention. They reduced traffic flows by promoting cycling and restricting when and where private vehicles may be driven. They separated cyclists and pedestrians from motorized traffic by creating bicycle paths and reclaiming sidewalks, which had been taken over by vendors and parked cars. They promoted safe behavior through public education campaigns, including employment of mimes at busy intersections to illustrate the use of striped ("zebra") crossings.

Legal reforms included the elimination of the city's traffic police force, widely seen as corrupt. Traffic enforcement was turned over to the national police. Bar and pub closing times were also moved up from 4AM to 1AM. A related public campaign sought to build respect for moderation in alcohol consumption.

Monitoring The independent Epidemiological Supervisory Committee on External Injuries was created in 1995 and charged with collecting data on RTIs in an objective, scientific manner. Statistics in 2002 showed a near-50% decrease in traffic fatalities from 1995.


Road traffic injuries are a hidden global epidemic. Though millions are killed and injured every year, few are aware of the heavy human and economic toll of crashes, particularly in developing nations. Millions are at risk -- deaths are expected to rise dramatically by 2020. However, such crashes are not unavoidable accidents: proven interventions exist which can save lives if action is taken soon.


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