An Olympic 400 m track has staggered start lines. Why? Because the outer lanes are longer — runners in lane 8 would run further than lane 1 if they started level.
Do the maths
Each lane is 1.22 m wider than the inside of the next. The extra distance per lap is roughly 2π × 1.22 ≈ 7.66 m per lane. Stagger fixes that exactly.
On a curve, going wider means a longer arc — even if it 'looks' the same length. Geometry gets you fair.