If you've been drinking
Alcohol impairs your judgement and can make you behave in a way you wouldn't if you were sober.
After a drink, your ability to judge distances and the speed of vehicles can worsen, making the likelihood of you having an accident much greater.
If you've been drinking, consider taking a bus or taxi home rather than walking. Alternatively, have a designated driver in your group who can make sure everyone gets home safely.
It's also important that you don't walk home along a canal or river if you're intoxicated; you could fall in and drown.