Texas DPS began enforcement of this driving in the latter part of 2013 in the Houston area.
I don’t know the results of this effort.
DPS to enforce left lane law today
snip
Although relatively unknown and rarely enforced, the state of Texas has a statute that
prohibits driving in the left lane of a multiple lane road, unless for the purpose of
passing other vehicles, or making a left turn.
Department of Public Safety troopers from Montgomery and Fort Bend counties will
spend today patrolling areas in Montgomery, Fort Bend, Waller and parts of Harris
County to enforce the statute.
“The violators of this statute (545.051 of the Texas Transportation Code) clog
freeways and highways causing needless obstructions to the smooth flow of traffic,”
said Warren Diepraam, chief prosecutor of the Montgomery County District Attorney’s Office.
end snip
Statute is cited at the source article.