Being a safe driver is more than just going the speed limit (though that is really important).  

Speed is a key factor and increases the likelihood of an accident significantly but there are a number of other considerations.

• 30% of all crashes are rear-end crashes - watch your distance.  A good general rule of thumb is to stay 3 seconds behind the vehicle in front of you.
• Fatigue is a major factor in road safety.  Simply don't drive when you are tired.
• Alcohol and drugs should never be mixed with driving.  Avoid the risks and plan ahead.
• It is illegal to use mobile phone when you drive.  Turn them off or give it to a passenger.  Avoid the temptation - put your phone in the glove box or console away from you and turn the ringer off.