WASHINGTON — If you think bad driving habits from car operators slow you down on the highway, you’re right.

According to the Associated Press, a new study in the U.S. concludes that drivers yakking away on their cellphones tend to drive about 3 km/h slower on congested roads than other drivers. By not keeping up with the flow of traffic, these drivers make traffic tie-ups worse.

The study, author David Strayer, a psychology professor at the University of Utah, doesn’t absolve motorists using handsfree devices either. They too are distracted, tend to drive slower, and have delayed reactions.

“People kind of get stuck behind that person and it makes everyone pay the price of that distracted driver,” said Strayer, whose study will be presented later this month to the Transportation Research Board.

The study found that drivers on cellphones are far more likely to stick behind a slow car in front of them and change lanes about 20 percent less often than drivers not on the phone.

Strayer says that drivers who commute an hour a day could lose up to 20 hours a year because of chatty drivers.

So, then, how many hours should truckers claim when they spend hours more sitting in traffic on any given day?

— with files from Associated Press