Good grief. I guess we have to go over this again. If you are driving on a Colorado highway, here's the difference. 

“The left lane is for passing — the right lanes are for normal driving.”

That is straight from the Colorado Department of Transportation. Plus, you can see the warnings up and down I-70 on those overhead signs.

In fact, Colorado law enforcement has begun to ticket drivers who are caught simply driving the speed limit in the left-lane. That lane is specifically for faster traffic that is passing other vehicles. The Colorado law goes to state that is the speed limit on a road in 65 m.p.h. or greater, no vehicle may travel in that unless such person is either passing other vehicles or unless the amount of traffic does not allow safe

It just seems odd to me that this simple concept gets lost on so many drivers. It isn't like a brand new law. This ranks #2 as the most frustrating thing for me. The top one is, of course, NOT turning into the closed lane at a four-way intersection. This an excerpt from a post I did previously on this subject:

"In a four-lane intersection and you are turning left, you must STAY in the closest lane. That is your lane. The outside lane is for the opposite vehicle to turn into his or her close lane. You do NOT have the authority, or the right, to drift all the way across both lanes over to the curb. Stay in the closest lane. Because I will turn right into my close lane and if you do not stay in your own lane and you hit me it is 100 percent your fault. It’s the law."

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