DES MOINES, Iowa — Kayden’s Law seemed like a “no-brainer” when it was passed in 2012.

Named for a 7-year-old girl who was killed in 2011 by a speeding motorist, the law imposed mandatory penalties for anyone not stopping at least 150 feet from a school bus when the bus’ red lights are flashing and its stop sign extended.

But the problem with “no-brainer” laws is legislators usually don’t think about all the consequences of their actions.