一份研究报告显示，美国每年有5000多人死于开车发短信和打电话，而20岁以下的驾车者尤其容易在开车时分神。

Texting and talking on cell phones behind the wheel kills more than 5,000 people every year on US highways. Teen drivers seem to be especially susceptible¹ to distraction², a study says.

A 2009 study focusing on drivers of larger vehicles and trucks has concluded that texting raised the risk of a crash by 23 times compared with non-distracted driving, says an environmental report.

Environmental researcher Uvid Hosansky, who authored the report for the journal CQ Researcher, wrote, "Texting drivers took their eyes off the road for each text an average of 4.6 seconds, which at 55 mph means they were driving the length of a football field without looking."

Talking on a cell phone is also dangerous. "Experts say that talking on a cell phone while driving is far more distracting than talking with an adult passenger because it consumes additional cognitive³ resources, including creating a mental picture of the person on the other end of the conversation," added Hosansky, who was twice nominated for Pulitzer Prize.

The National Highway Traffic Safety -Administration, US, estimated that 16 percent of all drivers younger than 20 years old involved in fatal crashes were believed to be distracted, "the highest proportion of any age group," by texting and mobile phone use, reports the journal CQ Researcher.

"Although some people may think they can safely talk and drive, researchers who observe people in driving simulators as well as in actual cars on the road find that a cell phone conversation will invariably（总是，不变地） intrude⁴ on a driver's attentiveness," said Hosansky.

"The distractions⁵ don't stop with cell phones. Car makers⁶ are adding new technologies to the dashboard, such as Web browsers⁷ and GPS units. Car makers say that such technologies are designed very carefully for safety, but safety advocates worry that they are creating even more hazardous⁸ driving conditions," Hosansky concluded.