It was a big and rapid slow down due to construction. By the time we passed this "event" it was stop and go down to one lane, due to the "event". DW was driving,
which allowed me to take the picture of the "event". I can see how it happened, she had to put the hammers down pretty hard, but the air over hydraulic brake on our rig prevented another "event",
these actually work and 'STOP THINGS'.
HJS