I suspect "normal"
if the white lines have built up paint then you will feel a quick pull to the left or right,,because your weight is usually on the center of the tyre , but as you go to the raised white line suddenly your weight is on the edge of the tyre that is raised of the floor by the paint,so you fall away from it and as you cross it you will pull towards it,
it is unnerving but you should expect it.