On a couple of occasions I have had first-hand experience with...

On a couple of occasions I have had first-hand experience with police-breathalysers on both myself and acquaintences both of us tested at the same time..
On one, the mate had 5 times the amount of ethanol as me but there was no way I would drive but he did. From past experiences with him I judged he would be OK as he showed no evidence of effects. He barely registered and I was on the limit. Eating the same for both of us.
The other time I was not the designated driver so did not hold back. I registered well under but the driver was just under. Eating the same for both of us.
What we need is an Akida-assisted breathalyser to take into account all the variables.