However, it doesn't take a lot to paralyze this area because of its complicated infrastructure.  DFW has tons of "mixmasters" where major interstate highways or toll roads intersect. These "mixmasters" often have several levels of highways crisscrossing over one another.
The one above happens to be the cloverleaf where I-75 and I-235 intersect.  When the temperature drops below freezing and stays there, these elevated bridges freeze, making them extremely dangerous.
Although Dallas is building in phases a mass transit system, the city is still primarily a commuter city.  Most people drive from the suburbs to their workplace every day.
When an ice and snow storm hits, it just paralyzes this metropolitan area.  Schools and businesses are closed today all over the area.
Truckers, who foolishly try to go through, are jackknifed everywhere.  When they start up an incline, the trailer starts sliding and soon is at a 90 degree angle with the truck pulling it.
That then blocks usually two lanes, making it impossible for those who HAVE to drive to get where they need to be.

Anyway, it is what it is, and I know that just a little north in Oklahoma it is much worse.  So, I'll be thankful for not having a blizzard as much of the country is now getting or about to get.