Travel through Iowa turned hazardous Thursday as a blizzard blew snow onto roadways and reduced visibility, leading to a massive traffic pileup west of Newton that closed eastbound Interstate 80.The strong northwest winds — gusting up to 47 mph in Cedar Rapids — also brought in arctic air and sent temperature plunging.At 7 p.m., the temperature in Cedar Rapids had fallen to 14 degrees — down from 34 degrees in the morning — and was on its way to below zero overnight.