Level Transition Travel Simulator  

This neat little addon simulates travel time between level transitions within a pre-defined range. By default it is 1-2 in-game hours, although certain transitions are adjusted depending on the distance between levels on the world map. For example, travel to and from underground labs usually takes only a couple of minutes. On the other hand, travelling all the way from the Deserted Hospital to the CNPP takes 3+ hours.

This helps simulate actual travel across the Zone, as transitions between distant levels are no longer instantaneous. Just one more thing to increase immersion.