This one bad driving habit is behind the most aggravating traffic jams clogging up your commute.

We’ve all been there – trapped in an ocean of glaring red brake lights, waiting for what seems like an eternity for the bumper-to-bumper traffic to clear. Yet when it does, there’s no obvious reason for traffic to have slowed to a crawl in the first place. No debris from an accident, no construction or lane closures – just a lot of frustrated drivers.

At best, this traffic is a minor inconvenience that delays you for a few minutes. At worst, it’s a risk that makes your chances of being in a crash skyrocket.

The fix for these pointless traffic jams is simple and free: a single change in driving habits. June is Lane Courtesy Month, time to drive home (no pun intended) an easy but often overlooked rule: don’t hog the left lane.

Left Lane Bandits Aren’t Just Annoying – They’re Dangerous

There’s a name for those motorists who have an inexplicable need to cruise along in the passing lane: left lane bandits. Their ability to slow down every driver in their wake is practically a superpower – a very annoying one.

The real harm of slower traffic taking over the passing lane goes far beyond frustrating everyone else on the road. The roadway is safest when traffic is flowing unobstructed. Research has proven that slowing down (unexpectedly) and changing lanes (unsafely) cause more accidents than speeding, Vox reported. On some level, it doesn’t matter whether drivers weave in and out of lanes to pass the slow-going left lane hogs, begin tailgating these slowpokes, or simply decelerate to accommodate the new, lower speed of traffic. The traffic flow has changed, and the danger has increased for everyone.

The 3 Best Benefits of Lane Courtesy

1. Faster travel times

Whether you’re driving to something you have to do or something you want to do, sitting in traffic is a waste of your time. You might be surprised just how much time: 111 hours a year for the average American, according to USA Today. I’m sure you could find something better to do with an extra 111 hours in your year.

When everyone is driving courteously and motorists are using the left lane only for passing and turning left, there aren’t unnecessary bottlenecks holding up your trip. You can get where you’re going faster, and guess what? You might even enjoy the ride.

2. Better gas mileage

Your car might not move very far in stop-and-go traffic, but you’re engine’s still running, and that means wasted fuel. Experts estimate that congested roadways in the United States waste as much as 1,900,000,000 gallons of gas per year, according to Business Insider.

Between the wasted gasoline and the wasted time, traffic jams cost American’s $124,000,000,000 – around $1,700 per household – every year, USA Today reported. And if you happen to be low on fuel when you get caught in congestion, you’re probably anxiously looking at the gas gauge, not the road.

3. Safer travels

Let’s face it: when drivers get stuck in congestion, they get antsy. Some tailgate slower drivers. Others shift lanes repeatedly, opening themselves up to a higher accident risk as they attempt to get around the slow driver blocking the left lane.

Even those motorists who quietly resign themselves to sitting in traffic become less attentive drivers. They fiddle with the radio more, pick up the phone, or take their eyes off the road to look around them – after all, they figure, they’re not going anywhere. When traffic starts moving again, this distraction can cause further delays or increase the risk of crashes.