I don't know where the diagram is from and I need to admit, that I did not think about the deadly hazzard limits of electricity yet.
But I nowhere found an indication, wheather the values hold for DC or also AC (and what is more dangereous)?

However, 1s seems to be quite long in my perspective. 54km/h is 20m/s or about 10 roations of the wheel per second. In other words the current will have changed direction about 130 times in 1s.