Picking the Smartest Line May be Dumb

Dear Car Talk

Dear Car Talk | Jun 14, 2016

Dear Car Talk:

Is it worth cutting into the curves when driving on multi-lane highways? For example, when on the interstate system, can I save fuel by switching lanes to reduce the distance traveled?

-- Marcel

Sure. We all know that the fastest route from point A to point B is a straight line. And that's what racecar drivers do: If there's a right-hand curve on the racetrack, they'll go from the far left side of the track, cut the right-hand corner at the apex of the curve, and then drift back out to the far left. That's the straightest possible line through the curve.

You can do that on the highway, too, Marcel. But why stop there? You can make your line even straighter by cutting through nearby neighborhoods. You can go right across the lawns and through the back yards. Just watch out for those in-ground pools.

Theoretically, you certainly can reduce your distance by a small amount and save a small amount of fuel. But the risk is that you'll cause an accident.

Since each lane contains vehicles, changing lanes inherently increases the risk of hitting one of those other vehicles -- or having it hit you. And if you change lanes frequently and unpredictably (or if it appears to be unpredictable to other drivers), you make the risk much higher.

So you might save 17 cents' worth of fuel but pay a $1,000 deductible to your insurance company and miss six months of work recovering from a broken butt bone.

So, theoretically, is this a good idea? Yes. Practically? No. Not at all.

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