There are too many drivers on the road who are not able to operate a vehicle safely, drink and drugs are only two of the reasons. The present law penalises people who are safe, competent and who are perfectly capable of having a drink and driving home without presenting a danger to others – they presently risk being penalised by exceeding a number which they have no way of calculating. The excuse that "They should not be drinking anyway" is irrevelant – such a law is bad law particularly where draconian penalties affect one (otherwise law abiding) section of the community while penalties for worse behaviour on the roads attract lesser sanctions.
Remove the present bad law that uses the "one over the 85" for deciding whether a driver is capable of safely handling a vehicle and replace it with a straightforward charge of "Driving While Unfit To Do So" – for whatever reason be it drinking, drug taking or simply not capable of operating a vehicle safely. The disablity lobby may object but is not the safety of all road users more important than inconvenience to a few.