Indiana State Police have handed out more than 200 tickets to motorists for driving too slowly in the left lane.
WRTV-TV reports state police ticketed 87 drivers in 2017 for left lane violations and 132 in 2018. It also gave more than 1,000 warnings last year.
A 2015 state law requires drivers to move to the right lane to allow faster traffic to pass.
Trooper Aaron Pfaff says slower drivers clogging the left lane can cause aggressive driving and road rage.
The Indiana Department of Transportation says it will periodically use alerts on its overhead highway message boards to help raise awareness about the left lane law.
