Definitely don't rely on 'winging it'... this is part of an article from an Automobile Association magazine (of all things!) looking at the word ‘instinct’. The article's about something suddenly happening while driving.

'Pre-planning works. Winging it, rarely does. The most mysterious thing at first glance is why the driver doesn't get out of the way. The answer lies in a thing called 'IQ Dump'. In a highly charged situation, an unprepared brain doesn't work too well. The enormity of the situation overwhelms it. The brain can't process all the information and order the body to take the best action. Instead, the brain works on instinct and usually simply tells the body to react. Instinctive reactions can kill you. If you are driving on instinct your brain won't tell your arms what's the best and safest thing to do. To beat these dangerous instincts, you have to seriously develop your skill options for a variety of situations so you know exactly what to do.'