Why do trains go on Heat restriction?

Question

My thoughts are that the tracks are metal, they heat up, metal expands and bends and you do not want to be a train traveling over a warped track at a high speed because 'derailment' could happen.

Answer 1

You are correct, rail can distort in high heat and kick out to one side several feet, in the old days we called this a "sun kink".

But that's not good enough now, it is known as "thermal buckling" but the result is the same. .

I imagine almost everyone here with much experience has some stories about sun kinks

slowing trains down has proven to help reduce stress on rail and roadbed.

personally, although I dont like sowling down any more than anyone else I think trains should be slowed down a bit more when the rail temp exceeds 130 degrees.