If you drink and drive

[Barrel of Fun]

One unit of wine is based on a 9.5% beverage and at 125ml.

It's quite possible to motor close to the limit on 'one glass' at home.

 

[Thunder Bolt]

http://www.standard.co.uk/news/london/fathers-heartbreak-after-shortsighted-driver-who-killed-his-son-avoids-jail-9050989.html

http://www.newsnortheast.org.uk/news/careless-driver-who-killed-oap-has-been-spared-jail

http://www.manchestereveningnews.co.uk/news/greater-manchester-news/driver-guilty-of-carless-driving-avoids-680320

You are confusing careless driving (known as driving without due care and attention) with reckless driving.

Someone else made the point about alcohol still being in the system the next morning. There is now tests for drug driving as cannabis can stay in the system for up to 3 days.