A good driver knows how their car will respond to heavy braking, cornering, or acceleration because they have practiced safely somewhere there is no traffic so they are not surprised by a situation.
The single most distinguishing factor is the ability to merge onto a highway. Bad drivers cannot do this without causing a ripple effect in the flow of traffic, causing other drivers the need to react. i.e. Needless lane changes or dangerous braking. Bad drivers on the highway do not know how to let other cars merge properly.
Good drivers on the highway maintain a constant speed and good drivers merging into traffic plan their merge to put their car in the space between cars at the speed of traffic. This simple cooperation is screwed-up by the majority of people.
A good driver:
• Knows the capabilities and limits of his/her car
• Maintains his/her car
• Keeps his/her tires properly inflated
• Inspects the car before each use
• Maintains complete situational awareness at all times
• Keeps to the right (or left, in the UK) except to pass
• Has no blind spot because the sport mirrors are adjusted correctly
• Never tailgates; if one is on a two-lane road and the driver ahead is going slowly, one adjusts one’s speed accordingly to maintain proper distance
• Never uses a cell phone while driving (hands-free or not)
• Is polite to other drivers; one always has the right to yield
• Never uses the horn except to avoid an accident
• Never takes his/her frustration out in road rage
• Has lights on at all times—they’re not just for the driver to see, they’re for other drivers to see you
• Won’t drive when inebriated
• Won’t drive when overly fatigued
• Uses the on ramp to get up to speed before merging
• Obeys traffic laws
• Allocates time for the trip taking into account the speed limits/possible traffic jams/weather conditions
• Adjusts speed according to conditions
• Knows how to hit/use the apexes to maintain speed and avoids braking in a turn
A bad driver:
Violates one, some, or all of these