as someone who 30 years ago laid rail for the RJ corman railroad, the hardest sites were in the southwest. track that can go from near zero to fifty celcius is not long for this world. if the job site was quiet some days you could even hear the ties groaning as the sun came up.

in the US we use a vision system on a special rail repair engine that checks for issues, but common controls are lowering speed and some days just not using certain tracks