“Don’t make me come back there!” 

Every parent has said it. Some of us end up saying it every time we get into the car with Lilliputian versions of ourselves. 

Pleas that it’s dangerous to distract mom or dad often fall on deaf ears.

If you want your munchkins to grow to adulthood, you may want to think of a more effective way to get that message across. A recent U.K. study concluded that the distraction of  squabbling kids in the back seat of your car slows down your reaction time as much as driving under the influence of alcohol. The Transport Research Laboratory study, carried out for Britain’s Direct Line insurers, found that fighting offspring decreased parents’ reaction by 13 per cent, resulting in an increase in stopping distance of four meters (13 feet) at highway speeds. 

That’s 13 feet – the length of a car. If you have to stop suddenly at highway speeds with kids fighting in the back, even if you maintain the requisite gap of two car lengths, your reaction time likely won’t be fast enough to prevent rear ending the vehicle in front of you.

Research data is getting incredibly specific. A landmark study released last year by the U.S. National Highway Traffic Safety Administration (NHTSA) and the Virginia Tech Transportation Institute (VTTI) monitored 100 cars for 12 months over approximately 3.3 million kilometers (2 million miles), resulting in almost 43,000 hours of video and motion dynamic data. Almost 80 per cent of crashes and 65 per cent of near-crashes recorded were caused by distractions during a three-second period before the crash. 

The very nature of driving requires impromptu decision-making. Taking your eyes off the road even for a fraction of a second means that you’re assuming other cars will continue in the path they were on when you averted your eyes, no one will miss a stop sign, run a red light, brake suddenly in front of you because a deer darted into the road, or fail to look before changing lanes.

Ahead of Ontario’s enforcement of its cell-phone ban last January, roadawareness.ca and Young Drivers of Canada held a distracted driving experiment at Formula Kartways in Brampton, Ontario. Local media were asked to drive a go-kart around a course once with both hands to establish a baseline for steering capability and reaction times to signals to stop. 

They were asked to do it again, with one caveat: by steering with one hand while texting or talking on a phone with the other. Observers measuring stop times recorded braking delays of half a second to a full second when the phones were in use. 

Half a second might not sound like much, but a car travels 28 metres (92 feet) per second at 100 kilometres per hour, said roadawareness.ca founder Shaun de Jager. A half-second delay in braking means you’ve lost more than 40 feet, roughly three car lengths. "Wouldn’t you like to have those 40-odd feet back if you have to stop quickly?” he asked.

Apparently not. According to a survey of Canadians commissioned by the Insurance Bureau of Canada in 2006, 89 per cent of Canadians were very or somewhat concerned about driver distraction. But 60 per cent of drivers said they wouldn’t stop using their cell phones while driving, despite being told that it made them four times more likely to be involved in a collision.

In Keith Code’s book A Twist of the Wrist, he compares riding a motorcycle with having $5 worth of attention to spend and being strategic about what you spend it on. If we apply that metaphor to driving a car full of kids, if you spend $2 on trying to resolve a squabble in the backseat, that takes $2 away from the attention you could spend on someone drifting into your lane. Our children need our attention, but so does traffic. If you want to keep your offspring alive, use whatever positive reinforcement methods you have to in order to eliminate the squabbles in the back seat. 

Spend your attention wisely.