re: Utah to drop blood alcohol limit to .05

BAC can be used as a guide to what effects alcohol may have on behaviour. People who drink alcohol regularly may show less effect at higher BAC.

A BAC of up to .05 g% is likely to cause a feeling of wellbeing. Likely effects are being talkative, more relaxed and more confident.
A BAC of .05 - .08 g% is likely to make you at risk of impaired judgment and reduced inhibitions.
A BAC of .08 - .15 g% is likely to put you in a risky state. Likely effects include slurred speech, impaired balance and coordination, unstable emotions and possibly nausea and vomiting.
A BAC of .15 - .30 g% will put you at high risk with likely effects to be inadequate breathing, unable to walk without assistance, loss of bladder control and possibly loss of consciousness.
A BAC of over .30 g% is likely to put you in a coma or result in death.

Link for stats

In 2016, there were 2,017 people killed in alcohol-related crashes where drivers had lower alcohol levels (BACs of .01 to .07 g/dL).

LINK

Also helpful tips for the OT drunks, If you will be drinking, plan on not driving. Plan your safe ride home before you start the party. Designate a sober driver ahead of time.
If you drink, do not drive for any reason. Call a taxi, phone a sober friend or family member, use public transportation, etc. Download NHTSA’s SaferRide app from Google Play or the iTunes Store which helps you identify your location and call a taxi or friend to pick you up.
If someone you know has been drinking, do not let that person get behind the wheel. Take their keys and help them arrange a sober ride home.
If you see an impaired driver on the road, contact local law enforcement. Your actions could help save someone’s life.