Why does Valentino Rossi's motorbike tyre have no traction line?

I'm a complete beginner and noob to bikes. I dont know shit, but i know that bikes are supposed to need traction and have those lines on the tyres.I saw Valentino's new post containing pics of his ride around the track and it didnt have lines on the tyres. Why is that so? Wouldn't that be no traction or what? The road seen in his pictures look like normal track roads so i dont know. via /r/motorcycles https://www.reddit.com/r/motorcycles/comments/d43jld/why_does_valentino_rossis_motorbike_tyre_have_no/?utm_source=ifttt