A Winter Weather Advisory is in effect for most counties in North Texas through 6 p.m. Tuesday.
Precipitation will be light, so no big accumulations of ice are expected according to NBC 5 Meteorologist Rick Mitchell. But an icy glaze began causing problems on bridges and overpasses as temperatures started to fall after sunset Monday.
As of 10 p.m. more than a dozen school districts decided to close or delay the start of school Tuesday.
Travel was so treacherous Monday night police were closing down several roads in North Texas.
In Denton, police closed U.S. Highway 380 near Loop 288 so that sand trucks could treat icy patches.
“For the first time since I have been doing this for five years, we had to shut the trucks down because we didn’t want to tear up the equiptment. This has been a bad winter,” said Lou Zion of Pursur Towing.
NBC 5 crews witnessed several crashes and traffic at a standstill because of slick road conditions.
A crash involving up to 20 vehicles was reported at Collins Street and Green Oaks Boulevard in Arlington.
Medstar reported it responded to 32 motor vehicle crashes between 6 p.m. and 9:30 p.m. Medstar also said it is prioritizing 911 calls to address the most life-threatening fist and any calls where the patient may be outside without shelter from the cold.
According to Flight Aware, as of 9:50 p.m. there were 100 flights leaving Dallas-Fort Worth International Airport and 144 flights coming into DFW Airport that had been canceled. More than 600 flights had been delayed.
Mitchell said everyone should prepare for the possibility of very slow traffic again Tuesday, especially during the morning rush hour.
Unfortunately we could see a second round of winter weather on Tuesday afternoon. Mitchell said there is a possibility of freezing drizzle that could mix with sleet or snow before ending Tuesday.
NBC 5's Julie Fine contributed to this report.