Why have nine lanes and not use lane 1? Isn’t it normally eight? Does the inside lane get a bit worn out from everyone being on it for 95% of the long races, so it’s a bit crappy for the sprinters?

Possibly that, but also the outer lanes have a larger radius to the bend, so would be easier to run in.

Ah yes. If anyone should know about wide turning circles…. 😕

2-9 are also closer to the crowd (if it’s the World Champs you are thinking of).

Does the inside lane get a bit worn out from everyone being on it for 95% of the long races,

Yes, plus many tracks are open to running clubs/public who all want to jog/train on the inside lane so often it is closed just to stop excessive wear.

I think they don’t use lane 1 for the 200 and 400m events as the radius of lane 1 is too tight and disadvantages the runner in that lane too much. But lane 1 seems to be used for all other running events.