At 5:00pm on a June evening in 2005, a Massachusetts motorcyclist collided with an oncoming SUV that turned left in front of him. The motorcycle burst into flames on impact, the 30-year-old rider was killed, and his passenger, his wife, was seriously injured. Neither the 18-year-old male SUV driver nor his female passenger was injured. The driver was held responsible only for the unsafe turn and lost his license for three years, during which time he will also be on probation. But there’s more to the story: the SUV passenger admitted to police that a portable DVD player was in use at the time of the crash. Though there was no legal finding that the driver was distracted by the DVD player, it would certainly explain why he turned in front of a motorcycle on an arrow-straight road in broad daylight. And it wouldn’t be the first time a distracted driver caused a crash.

In a recent report the US Department of Transportation’s National Highway Traffic Safety Administration estimates that nearly half of all road crashes are caused by driver inattention. This is higher than previous estimates of 25-30% but at the same time is much more compelling because of the way the study was done. For 18 months, 100 motorists in the DC metropolitan area drove cars equipped with an extraordinary array of instrumentation. Data recorded whenever the vehicle was in use included:

• vehicle dynamics—speed, acceleration, braking, turning
• proximity to other vehicles—from doppler radar front, rear, and side
• driver activity—from multiple in-car video cameras

To estimate the effect of inattention researchers studied 69 crashes and 761 near-crashes (determined by emergency maneuvers and proximity to other vehicles) that occurred in the test fleet. While inattention was to some degree "involved" in 80% of the crashes, that alone is not a compelling conclusion. It depends also on the occurrence of distractions in crash-free driving. If drivers are no more likely to crash when on the phone than when driving attentively, maybe it’s not a distraction. Only if an activity is more likely to be observed before a crash than in crash-free driving can it be regarded as a cause.

So researchers compared driver behavior at the time of the crashes and near-crashes to behavior at other times—20,000 randomly selected "epochs" of 6 seconds duration in which they watched video of the drivers. These observations made the study unique because it enabled them to identify both normal and pre-crash behaviors and to learn what differs in crash situations. They found that moderate tasks such as changing CDs increased crash risk by a factor of two, and complex tasks such as dialing a phone increased risk by a factor of three. Moderate and complex distractions combined—including phone use, reading, eating, and makeup application—were estimated to cause 19% of crashes. Perhaps a scarier conclusion is that moderate to severe drowsiness accounts for 25% of crashes. It can be hard enough for a driver to spot a motorcycle when he’s wide awake, let alone when he’s nodding off.

The effect of driver inattention on motorcyclists isn’t addressed in the NHTSA study—apparently no motorcycles were involved in the 69 crashes—but in the 2004 MAIDS study of 921 motorcycle crashes in Europe, driver distraction contributed to 20% of multi-vehicle crashes. That result underestimates the true impact, though, because the MAIDS researchers could make a determination of distraction only if the driver admitted to it when interviewed. Driver inattention will be more prevalent in car-vs.-motorcycle crashes than in car-vs.-car crashes simply because a motorcycle is harder to see. A driver just at the threshold of attention that allows him to see another car would probably fail to see a motorcycle because it’s smaller and blends in readily with the other traffic and the background. Countermeasures

Other drivers may think they can’t do anything about those who are inattentive, that they are an indigenous hazard from which a cautious driver protects himself with the safest vehicle he can afford. Some motorcyclists probably see inattentive drivers in the same way: If it happens, it happens, and good emergency skills and top-notch safety gear are the most that one can do to reduce risk. But that’s not nearly good enough. In the worst case emergency skills can’t prevent a crash, and in many crashes no safety gear in the world can save the rider’s life or prevent permanently disabling injuries. As with other hazards, the best protection against a distracted driver is to identify him before he becomes an imminent threat. The earlier he is detected, the easier he is to avoid.

Inattentive drivers are a hazard that a skilled rider can anticipate and avoid with SEE, the Motorcycle Safety Foundation’s survival strategy:

• Search. Actively scan the roadway from immediately in front of you to 12 seconds ahead for potential hazards in the forward quadrants, and periodically check mirrors and blind spots for danger in the 3 o’clock to 9 o’clock area.
  
  
• Evaluate. When you see a problem developing, predict how it might unfold and decide how to avoid it.
  
  
• Execute. If the situation progresses toward a crash, take the planned evasive action.

But, aside from the obviously distracted driver with a phone to his ear, a latte in one hand, and the sports page in the other, how can you spot inattentive motorists? According to police officers who specialize in traffic enforcement, they’re very much like drunks. "Impaired is impaired," one officer told me. This suggests that motorcyclists draw on the experience of law enforcement and look for the same behavior that alerts them to potentially impaired drivers. As an added benefit, we can also spot drunks, another serious threat to motorcyclists.

As you scan traffic looking for routine hazards—traffic lights, vehicles entering and exiting the roadway, pedestrians and bicyclists—look also for vehicles exhibiting these signs of inattention:

• Obvious distractions. Driver using the phone (especially dialing), reading, eating, or applying makeup.
  
  
• Lane position. Weaving within the lane, crossing lane lines or the road centerline, sloppy turns—cutting a corner at the apex or running wide at the exit.
  
  
• Speed and braking. Unsteady speed, driving 10mph or more under the limit, abrupt braking, stopping far beyond or short of the limit line at an intersection, riding the brake pedal and showing brake lights but not slowing.
  
  
• Vigilance. Lights off at night, failure to cancel turn indicators, cutting off another vehicle when turning or changing lanes, remaining stopped when the light turns green.
  
  
• Judgment. Following too closely, excessive speed for conditions, poorly judged turn speed followed by a mid-turn correction, risky lane changes or turns.

If you’re currently scanning traffic effectively, you won’t have to change your visual pattern. The vehicles you’re concerned about are in your normal field of view. However, you must learn to respond to cues that you might have previously ignored. We all see drivers on the phone and vehicles stopped 6 feet beyond the limit line or traveling 20mph slower than the rest of traffic. But knowing that they may be distracted adds to your workload because each one is another target to track.Examples

Here are some situations where you can apply this knowledge about inattentive drivers to anticipate trouble and be ready to react:

References