How did the deep ruts in Turkey’s Phrygian Valley form?

Repeated traffic is a plausible explanation, but the depth alone doesn’t prove it. Softer volcanic rock can wear down over a long period, especially if the same routes were used again and again. The useful evidence would be the rut profiles, their relationship to the surrounding rock, and whether they connect with known roads or settlements.

The claim that the grooves were made millions of years ago by vehicles is a much bigger leap. If the rock is millions of years old, that tells us when the rock formed, not when the ruts were cut. A proposed date for the tracks needs evidence from the tracks themselves, not just the age of the underlying stone.

I’d be cautious about treating “two metres deep” as a settled measurement or as proof of extraordinary technology. The account gives a striking figure, but doesn’t provide a method for measuring it or enough detail to test competing explanations. Odd-looking features deserve investigation, but an unknown transport system is not the only alternative to ordinary road wear.

Could also be that different sections formed in different ways. Before settling on one explanation for every rut, I’d want to know whether the channels have consistent shapes and spacing, and whether they show signs of wheel use. A site can look uniform from a distance while the details vary.