In the KNP, all vehicles (self-drive, SANParks guided drives, commercial guided drives) may use the public roads from the time the gates open in the morning, until they close in the evening. That means sightings are a first-come-first-serve, free-for-all, self-regulated show. The result may occasionally be chaos and mayhem, but usually not. It is equally possible, probably more likely, that the number of vehicles at a sighting is fairly low, or if you are lucky only one (you). On public roads, you are welcome to stay at a sighting for as long as you feel like. I've known people to stay for the whole day.
In the KNP, SANParks guided drives may and do use roads not open to the general public, and may drive outside of gate hours. That means they have sightings to themselves, i.e. one or maybe two vehicles max.
In the KNP, certain lodges on private concessions are also allowed to use a number of designated public and management roads outside of gate hours.
On private land, the land owners and/or lodge operators make up their own rules. They can be very imaginative and creative, the rules can be very numerous and vary depending on a host of factors. Quite a few are also, in my opinion, downright silly. In any case, they usually boil down to this:
- the number of vehicles at a specific sighting is restricted to X (usually between two and four)
- If the number of vehicles responding to a sighting exceeds X, the incoming vehicles have to "take a standby".
- If there are vehicles on standby, the vehicles at the sighting will have to make room for waiting vehicles after Z minutes (10 or 15 is common).
There are any number of refinements and exceptions to these rules, differing from reserve to reserve.
Private lodges on concessions in National Parks operate on the same principle. As they are constrained by SANParks regulations, they have a bit less leeway to make up their own rules, but when it comes to behavior at sightings the differences are small.
At private lodges game vehicles
do not drive in a caravan. On the contrary, they spread out in as many different directions as they can in their endeavor to find as many interesting animals/sightings as possible. A specific sighting will therefore almost always be found/tracked down/chanced upon by a single vehicle. If interesting enough, other vehicles will be notified and may then choose to respond. Depending on the size of the reserve, the condition of the roads and their location, they may take anywhere from a few minutes to an hour to get to the sighting. That means that sightings often become partially self-regulating, in the sense that various vehicles will arrive at various intervals, thus allowing for a fairly regular turnover at the sighting. It is in reserves with a very high density of vehicles (Madikwe immediately comes to mind) that sightings can become ridiculously congested, even to the point where the standby list becomes oversubscribed. This issue is exacerbated when all these vehicles mostly utilize certain parts of the reserve where game concentrations are much higher than elsewhere (Madikwe comes to mind again).
As an aside, I know of a few instances where private game viewing lodges have resorted to "caravan" game drives, albeit against their will. These all involved large groups of Chinese tourists chaperoned by a asssertive guide who insisted that "all guests must see same animal!". The guests were then packed into half a dozen or more OSVs, which all drove single file down the same roads.
On one occasion, such a large group had also booked a game walk. The solution was to march all 40+ of them through the bush single file, with armed rangers inserted into the column at seven-guest intervals.
For some funny reason, they did not see that many animals.
Finally, there's no such thing as a "single vehicle drive". Well, in a sense all drives actually are, but I suspect you are referring to sole use of vehicle (SoV), which usually comes at a (steep) extra. SoV just guarantees you that you will not share the vehicle with any other guest than those belonging to your party. It does not guarantee you that you will have all sightings to yourself for as long as you want.
However, enough money will buy you almost anything. There's a lodge on a concession in Kruger that will charge you an arm and a leg, but also bend over backwards to accommodate your wishes. They have a regular guest who has stipulated that on her sole-use-of-vehicle game drives no other vehicles should be encountered, not even glimpsed in the distance. The lucky guide assigned to drive her around has his work cut out for him, as he is kept extremely busy on the radio coordinating with all the other vehicles out there to make absolutely sure they do not meet. It also means they are invariably the last ones at any sighing, as they can only approach when all the other vehicles have left, and only along an empty road.
This same lady, when she feels like having a meal, will first phone the restaurant to make sure no other guests are in. If there are, she will have the meal served in her room instead.
The really upmarket lodges get more than their fair share of eccentrics!
Johan