Shinkansen train system secures deceleration by controlling braking force according to adhesion characteristics as the speed changes, preventing wheel slide.
Emergency braking distance of Shinkansen is just under 4000m (for E2 series trains at 275km/h)
One of the reasons the Fastech 360 trains on the Shinkansen are still not feasible for operation at the rated 360km/h because of large braking distances (of ~7000m).

shinkansen-braking