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Status Report, Vol. 46, No. 7 | August 18, 2011 Subscribe

Low-hanging fruit: Existing countermeasures merit renewed attention

Oftentimes saving a life on the road is as basic as getting people to slow down, buckle up, or don a helmet. Tried and true countermeasures like these usually don't grab headlines, but if they were more widely propagated across the nation they would yield an immediate reduction in motor vehicle crash deaths. The number of people who die in crashes in the United States is at a record low. Still, there were an estimated 32,788 motor vehicle crash deaths last year, according to a preliminary projection by the National Highway Traffic Safety Administration (NHTSA). Vehicles are safer than ever, and emerging technologies are starting to pay dividends in terms of preventing crashes or lessening their severity (see "Volvo's City Safety prevents crashes at low speeds and reduces insurance costs," July 19, 2011). New safety features take time to work their way through the vehicle fleet, though, so benefits can be delayed for years.

"While we're looking for the next big breakthrough in vehicle safety, we should keep in mind that many existing strategies at the driver and passenger level still can yield gains," says Adrian Lund, Institute president. "Not only can most of these countermeasures be put to work now, but the benefits also would be swift."

State laws have helped lift use of safety belts and motorcycle helmets and lower teenage driver crash rates. DUI/DWI laws and sobriety checkpoints have reduced alcohol-impaired driving. Red light cameras and speed cameras have gotten drivers to obey traffic signals and slow down, while roundabouts have reduced intersection crashes.

Still, lots of drivers flout traffic and restraint laws, intersection crashes and speeding-related ones continue to be deadly, and some teenagers take risky chances that have tragic endings.

Motor vehicle crash deaths, 1975-2009

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"We already have the tools to address these problems," Lund says, "but they need to be better utilized." Basic doesn't mean easy, he adds. "Making headway in many cases would require some state lawmakers to make bold moves to enact tough, enforceable laws."

A stumbling block is getting the public and state and local politicians on board with proposed changes. Red light cameras and speed cameras are especially divisive, even though public opinion surveys show solid support for using cameras to enforce traffic laws. Motorcycle helmet laws can be just as controversial. Antihelmet groups pressure state legislators every year to overturn helmet laws or reject proposals for new ones. This is in spite of the fact that helmets are the No. 1 countermeasure for preventing rider deaths in crashes.

What follows is an overview of some proven countermeasures with quick payoffs.

Enact primary belt laws

Using safety belts is the single most effective way to reduce deaths and injuries in crashes. Safety belts saved 12,713 lives in 2009, NHTSA estimates. If all passenger vehicle occupants 5 and older involved in fatal crashes had been restrained, an additional 3,688 lives could have been spared.

Safety belt use is up sharply from just a decade ago, thanks to a combination of high-visibility enforcement via a nationwide Click It or Ticket campaign, passage of primary belt laws, and enhanced in-vehicle belt reminders (see "It's simple: Click it or ticket," July 11, 2009). The national belt use rate climbed to 85 percent in 2010, data from NHTSA's National Occupant Protection Use Survey indicates.

States with primary belt laws, which allow police officers to stop motorists solely for not buckling up, generally have higher use rates. Thirty-two states and the District of Columbia have primary belt laws. Rhode Island is the latest state to upgrade to primary enforcement. In other jurisdictions, police must have another reason to stop a vehicle before citing an occupant for failing to buckle up. Only New Hampshire lacks a belt law. Belt use is lower among back-seat occupants than front-seat ones. Laws in just 26 states and D.C. cover everyone in the vehicle, whether riding in front or back.

Institute research has shown that switching from a secondary to a primary law reduces passenger vehicle driver deaths by 7 percent. If all states with secondary laws upgraded to primary laws, an additional 284 lives would have been saved in 2009.

Another way to boost belt use is to increase fines for belt law violations. A recent NHTSA-sponsored study found that increasing fines from the national median of $25 to $60 results in gains of 3 to 4 percentage points in belt use. Raising fines to $100 increases belt use even more (see "More people buckle up amid higher fines for violations," March 1, 2011).

Mandate helmets for all riders

Helmets saved the lives of 1,483 motorcyclists in 2009, NHTSA estimates. If all motorcyclists had worn them, an additional 732 lives could have been saved. Helmets are estimated to be 37 percent effective in preventing fatal injuries to motorcycle drivers and 41 percent effective for motorcycle passengers.

Nearly all motorcyclists wear helmets in states with universal helmet laws covering riders of all ages, but only about half do when states either don't have a law or the rules only apply to some riders. Twenty states and D.C. have universal helmet laws, and 27 states have partial helmet laws usually covering younger riders. Illinois, Iowa, and New Hampshire don't require helmets at all.

In 2010, 98 percent of motorcyclists observed in states with universal helmet laws were wearing helmets. In states without such laws, use was 48 percent. Based on helmets judged to be compliant with federal safety regulations, use was 76 percent in states with universal laws and 40 percent in states without such laws.

Many states specifically require helmets that meet U.S. Department of Transportation performance standards. A growing number of riders, however, choose flimsy helmets that don't meet these standards. Novelty helmets put riders in a crash at higher risk of a brain injury or skull fracture than compliant ones. To curb the problem, NHTSA has issued new labeling requirements that take effect in May 2013 (see Status Report special issue: motorcycles, Sept. 11, 2007, and "Revamped labels to help curb sale of unsafe helmets," July 19, 2011).

Toughen teen driver laws

Teenage drivers have the highest crash risk per mile traveled, compared with drivers in other age groups. One proven way to reduce this risk is through graduated licensing laws that phase in driving by young beginners as they mature and develop skills. States with these systems have reduced teen crashes 10-30 percent.

Whether a state has a strong graduated licensing law matters in terms of safety. In 2009 researchers at the Institute and affiliated Highway Loss Data Institute evaluated the effects of various provisions of teen licensing laws on fatal crash rates and rates of insurance collision claims for 15-17-year-old drivers. The findings indicate strong benefits of restricting when teens are allowed to drive and how many teen passengers may ride along (see Status Report special issue: teenage drivers, May 7, 2009).

Delaying licensure and permit age helps to reduce teen drivers' fatal crashes, and requiring more practice driving hours lowers teenagers' risk of collision claims. Delaying licensure from 16 to 17, for example, lowers the fatal crash rate among 15-17 year-olds by 13 percent.

Most states license at 16, 16½, or somewhere in between, and a few license younger than 16. Only New Jersey waits until 17, which lowers fatal and injury crash rates per population among 16-17 year-olds (see "Licensing teenagers later reduces their crashes," Sept. 9, 2008).

Surveys indicate that parents are ready for strict teen driver laws. Two-thirds of the parents in a 2010 Institute survey said they'd prefer starting learners at 16 or older. More than half support intermediate licensing at 17 or older. A large majority favor night driving restrictions beginning by 10 p.m. or earlier and restricting teen passengers to 1 at most. Nearly half said these restrictions should last at least until age 18 (see "Parents favor strict rules for teen drivers and higher licensing age," Aug. 3, 2010).

Strong GDL laws might not be a hard sell for teens either. The majority of 15 to 18 year-olds polled in a 2010 Allstate Foundation survey said they favor night driving restrictions that begin at 9 or 10 p.m. and restrictions that limit teen passengers to 1 or none.

Pending before Congress is the STANDUP Act, or Safe Teen and Novice Driver Uniform Protection Act, which would create a national model for graduated licensing and provide grants to states for enacting the basic tenets.

Lower speed limits

Speeding was a factor in 31 percent of all motor vehicle crash deaths during 2009, and 10,591 lives were lost in speeding-related crashes. Lowering speed limits has been proven to pay big dividends. Raising them has the opposite effect (see Status Report special issue: speeding, Nov. 22, 2003).

Congress in 1995 repealed the national maximum speed limit of 55 mph, allowing states to set their own limits. A 2009 study in the American Journal of Public Health found a 3 percent increase in road fatalities attributable to higher speed limits on all road types, with the highest increase of 9 percent on rural interstates. The authors estimated that 12,545 deaths were attributed to increases in speed limits across the U.S. between 1995 and 2005.

States continue to raise limits on interstates and major highways to 70, 75, 80, and even 85 mph. Kansas, Ohio, and Texas are the latest to allow faster speeds. The American Trucking Associations favors a national maximum limit of 65 mph for all vehicles — not just trucks — as a way to reduce fuel consumption and carbon emissions. The group has petitioned for speed limiters to restrict large truck speeds to no higher than 65 mph.

Use automated enforcement

A proven way to curb speeding and red light running is to use cameras to enforce traffic laws. The most common use in the U.S. is at intersections to record red light violations. Red light running killed an estimated 676 people and injured an estimated 130,000 in 2009.

Red light cameras saved 159 lives in 2004-08 in the 14 biggest U.S. cities with cameras, a February 2011 Institute analysis shows. Comparing these cities to those without cameras, researchers found the devices reduced the fatal red light running crash rate by 24 percent and the rate of all types of fatal crashes at signalized intersections by 17 percent. If cameras had been operating during that period in all cities with populations greater than 200,000, a total of 815 fewer people would have died. What's more, two-thirds of drivers in these same cities with longstanding red light camera programs support their use (see Status Report special issue: red light running, Feb. 1, 2011, and "Red light cameras see solid support in latest survey," July 19, 2011).

Speed cameras are widely used in Europe but not in the U.S. (see "U.S. trails other wealthy nations on road safety gains" in this issue and Status Report special issue: speed, Jan. 31, 2008). The cameras are associated with reductions of 8-49 percent for all crashes, 8-50 percent for injury crashes, and 11-44 percent for crashes involving fatalities and serious injuries in the vicinity of camera sites, a 2010 Cochrane Collaboration review of 28 studies found. Over wider areas, the review found reductions of 9-35 percent for all crashes, and 17-58 percent for crashes involving fatalities and serious injuries.

Institute studies in Maryland and Arizona found that the proportion of drivers exceeding speed limits by more than 10 mph fell by 70 percent and 95 percent, respectively, after cameras were introduced. Speeds also fell on roads outside the enforcement area (see Status Report special issue: speed, Jan. 31, 2008).

Conduct sobriety checkpoints

The proportion of fatally injured drivers with blood alcohol concentrations (BACs) at or above 0.08 percent has remained about a third since 1994 after declining from nearly half during 1982. The Institute estimates that 7,440 deaths would have been prevented in 2009 if all drivers had BACs below 0.08 percent.

Sobriety checkpoints help to deter alcohol-impaired driving and catch violators. The Centers for Disease Control estimates that crashes thought to involve alcohol drop by about 20 percent when well-publicized checkpoints are conducted.

Police officers set up checkpoints at predetermined locations and stop all drivers, or a predetermined proportion of them, based on rules that prevent police from arbitrarily selecting motorists to stop. Officers then look for drivers who appear intoxicated or impaired and screen them.

Thirty-eight states and D.C. conduct sobriety checkpoints, the Governors Highway Safety Association says. States vary a lot in terms of numbers and frequency. NHTSA strongly supports regular use of checkpoints. The 2 keys to success are publicity and frequency. If checkpoints are held often over long enough periods and are well publicized, motorists assume police are cracking down on impaired drivers, even if other enforcement hasn't been stepped up. This helps to dissuade people from driving after drinking.

Build roundabouts

Used in place of stop signs and traffic signals, these circular intersections can significantly improve traffic flow and safety. Where roundabouts have been installed, crashes have fallen about 40 percent, and injury-related crashes have slid about 80 percent. Some of the most common types of intersection crashes are right-angle, left-turn, and head-on collisions. These can be severe because vehicles may be traveling at high speeds. Roundabouts essentially eliminate potentially serious crashes because vehicles travel in the same direction and at much slower speeds. Keeping vehicles moving also reduces travel delays, fuel consumption, and air pollution (see "Roundabouts can be even safer with easy changes," June 9, 2008).

"Roundabouts are the preferred safety alternative for a wide range of intersections," the Federal Highway Administration says. The agency recommends considering them for all new intersections on federally funded highway projects and also existing intersections that need major improvements.

U.S. drivers aren't as familiar with roundabouts as drivers in Europe and Australia. When they are proposed here, some motorists worry that they will be confusing and tough to navigate. But opinions quickly change once people grow used to them (see "Indiana city takes roundabout path to safer roads," Nov. 3, 2010, and "In other highway safety news ...," Aug. 26, 2003).

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