In New Zealand, when you are towing a trailer, the rule you should follow is the "Four-Second Rule." This rule means that under normal driving conditions, you should ensure that you maintain at least a four-second distance from the vehicle in front of you. The main reason for this is that when towing a trailer, the stopping distance of your vehicle is extended, requiring more time and space to safely stop or slow down. Adhering to this rule helps reduce the risk of collisions caused by following too closely. Remember: the four-second principle should be extended to greater distances in adverse weather conditions, on slippery surfaces, or when towing, as you will need more time to stop.