A driver should look 10-12 seconds ahead as opposed to focusing only on the vehicle in front of them. This is where many trouble spots have the potential to begin. To see how far 10-12 seconds ahead is, pick a stationary object, like a traffic sign or street light, and count the seconds it takes for you to pass the object. If you are passing the object before the seconds are up, pick an object slighty further ahead. This will give you a good idea of how far ahead you should be scanning the road.
2) Size up the whole scene:
You should be continually scanning for bicycles, pedestrians, construction sites, congested traffic, other drivers and changing road conditions. This would include checking your review and side mirrors every few seconds to spot potential problems.
3. Signal your intentions early:
When you use your turn signals, horn or lights, it alerts other drivers of your plans and helps them make their own defensive driving decisions. Use them appropriately to avoid potential problems.
4. Plan an escape route:
To maneuver smoothly, carefully time your passing moves and avoid tailgating. Thinking ahead to give yourself more room, time and visibility to stop will help avoid a crash.
5. Take decisive action:
Any driver who follows the previous 4 principles should be able to react correctly and safely in most traffic situations. Defensive driving ultimately comes with experience!