As demonstrated in a previous post here: https://pwayblog.com/2015/10/29/11-82_cant-deficiency-un-compensated-acceleration-pway/ , the cant deficiency is the conventional representation of the uncompensated lateral acceleration.
And since cant deficiency is an acceleration, we can easily represent it as a percentage of g, the gravitational acceleration.
The formula that relates the cant deficiency D to un-compensated lateral acceleration is:
The percentage of g can be therefore calculated from the following formula:
With this formula we can now compare the limits we have to cant deficiency with the ones we have for vertical curves (UK rules exemplified here):