TULSA, Oklahoma - A new state law took effect today forcing highway drivers to stay out of the left lane unless they're passing other vehicles. 

If you don't, the Oklahoma Highway Patrol says you could face a $235 fine for violating the new law.

The law states you can only drive in the left lane when you're overtaking and passing another vehicle. 

Troopers say they will be strictly enforcing the law.  

The state legislature passed it earlier this year and Governor Mary Fallin signed it into law in May.  Both say they hope the new law will reduce road rage and give more room for emergency vehicles.

It shows driving in the left lane is OK if traffic problems or road configuration, like the merging of traffic forces you to use the left lane.