'Threat avoidance' is an umbrella term for multiple preventative measures that can be taken in order to avoid a developing situation or potential developing situation as a result of maintaining threat awareness and utilising threat evaluation. In that context, this will be the moment when a predefined action trigger has been tripped.
Relocation
The most effective preventative measure is also the simplest - don't be there! Avoid places, people and situations you perceive to be potentially threatening. Failing that, walk away from potential threats before a situation develops without attracting undue criminal attention to yourself. Failing that, escape a developing situation via the safest and fastest method you can find.
The balance between speed and safety is important to find in escaping a developing situation.
Useful Skills and Training for Threat Avoidance
Cardio exercise is essential for the physical difficulty that can be encountered in threat avoidance. You may find yourself in a situation requiring running a significant distance, or in undesirable conditions (weather, terrain, etc).
Freerunning/parkour should be trained to gain an awareness of potential methods of overcoming obstacles in order to effect a more efficient escape. In addition, the fitness benefits of this training are extremely beneficial. Beware of tricks and flips in this kind of training - remember your goal is efficiency and safety if you're being pursued. The easiest, quickest and safest option should always be the one you take.
It is good practice to introduce escaping to self-protection drills, whereby once the practitioner gains the opportunity they run away from their partner.