Moving during these storms is the exact opposite of what is recommended, seek shelter immediately is always the recommended course. Any shelter is far better than being caught in the open or in a vehicle. As you can see form the graphic above Tornadoes shift paths to some degree. Even with 15 minutes moving a large mass of people would never get them all out of the way in time, and the loss could have been worse. Even one full school bus picked up by the winds. Now if parents were there an hour or so before they should have been given their kids, but in the minutes leading up to the actual strike that too would have been an indeed distraction and a risk.
Well all I can say is this I have been through several of these and have seen the aftermath! When you see a 2 foot steel I beam twisted in a knot, you know there is only one plan leave,
go as fast as you can when the siren goes off! Check the radar before you go and go perpendicular to the storm cell!
When you see miles of nothing but empty lots with nothing but house material strewn for what looks like forever you know your 2x4 house will not save you.
We have built some homes with shelters in the past for people with 2’ concrete walls and ceilings to hold up in. But if you do not have what we call a fraidie hole best is get outta Dodge. Some Federal Buildings and City ones have shelters and may be a good spot!