The first study of drivers texting inside their vehicles shows that the risk sharply exceeds previous estimates based on laboratory research  and far surpasses the dangers of other driving distractions.

The new study, which entailed outfitting the cabs of long-haul trucks with video cameras over 18 months, found that when the drivers texted, their collision risk was 23 times greater than when not texting.

The Virginia Tech Transportation Institute, which compiled the research and plans to release its findings on Tuesday, also measured the time drivers took their eyes from the road to send or receive texts.

In the moments before a crash or near crash, drivers typically spent nearly five seconds looking at their devices  enough time at typical highway speeds to cover more than the length of a football field.