Yeah, they suck gross polluters out of the state ;)
I've frequent Nevada for last 30 years and historically it used to be state who never disturbed visitors on the road.
But in last years the 40 miles 6-lane freeway between state line and LV is stuffed with cops and occasional radar traps. The check station entering LV was mostly closed in the past. Now is mostly open. Add annual smog checks in NV v/s biannual in CA. Go figure.
UT is low-population state, so those things might get delayed, but sooner or later you will see them coming.