Every time you disable one of Vaas’s radio scramblers, you also open up a Supply Drop mission. Somewhere nearby, the Rakyat have an urgent delivery to make, but their delivery man has been killed. It’s up to you to finish the job.
The starting point for it is found somewhere near the radio tower, typically at its base or somewhere near one of the ziplines attached to its top, and is labeled on your map with a
. The goal is simple: get from point A to point B as fast as you possibly can. Your route to your goal is indicated by lit flares scattered across the road, as well as target indicators on your minimap.
The point of a Supply Drop is to deliver the medical supplies inside a yellow backpack, which can be found in or on the vehicle required for the Supply Drop. You must get that backpack, and thus the vehicle, to the final stop, although it does not have to be in good condition when you get it there. As long as the backpack is fine, you can leave the vehicle in a smoking heap at the finish line and receive full credit. You cannot, however, finish a Supply Drop on foot after you’ve wrecked the vehicle.
The time limit on Supply Drops is very tight, often clocking in under 90 seconds. You do not have to touch every flare along the path in order to succeed; in fact, if skipping a flare saves a couple of seconds, you should do that whenever possible. If you run into trouble on the road, such as stray buffalo or armed pirates, or if you crash or roll your vehicle, just restart the mission. You’ll lose too much time to have any real chance of completing it. That also means that you cannot simply power through the entire run with your foot all the way down on the accelerator, as many of the Supply Drops are done on trikes or ATVs, and those are just as rollover-prone in-game as they are in real life.
One helpful trick, particularly early in the game when the pirates control more territory, is that any random encounters that have spawned in the general area of a Supply Drop will vanish if you manually restart the mission. This includes armed opponents along the road, who can inflict enough damage on your vehicle that it may get totaled before you reach your goal.
You get 250 EXP and a small sum of money ($175 to $500) for finishing a Supply Drop. To earn the Road Trip Achievement/Trophy, complete any Supply Drop quest. You must also complete three of them to unlock the Adrenaline Surge skill for purchase, which vastly speeds up the rate at which partially depleted health blocks regenerate. If you complete all eighteen Supply Drops, it counts towards 100% completion in your Handbook but has no other benefits.