Road vs Air: What It Costs to Move Relief Cargo Inside South Sudan

Tony Miller
Aug 28
7 min read

Airdrops into South Sudan can cost as much as 17 times road transport and deliver much less cargo in the same timeframe, according to WFP. Road is always the cheaper modality. The catch is that road is only available for part of the year, so the real decision is made months before the cargo moves.

What does air actually cost compared with road?

The cleanest published figure comes from WFP's own South Sudan operation: airdrops there "can be as much as 17 times more expensive than road transport", and they move much less cargo per rotation. Globally, WFP puts the airdrop premium lower, noting that the cost of aircraft, fuel and personnel can run seven times higher than road, and that a single truck convoy can deliver more than dozens of flights. The gap between the two figures is South Sudan itself: longer sectors, dirt airstrips, no commercial competition on the route, and cargo that has already been flown or barged a long way before it goes airborne again.

Airdrop is the extreme case. Landing cargo on an airstrip is cheaper than dropping it, and helicopter lift sits between the two. We are not going to quote a hard multiple for landed air cargo, because no institutional source publishes one for South Sudan and a made-up number is worse than none. What is safe to say, and what every country logistician already knows, is the ranking: river is the cheapest per tonne on the routes it serves, road is next, landed air is a long way above both, and airdrop is the most expensive thing you can do with a pallet. WFP treats airdrops as a last resort, used only when there is no other way to reach people.

Two things follow for a budget holder. First, the modality decision is worth more than almost any unit-price negotiation you will run this year. Second, because the multiple is so large, a small percentage of your tonnage moving by air can dominate the transport line in your budget.

Why is road only available for part of the year?

Because there is almost no paved road to be seasonal about. South Sudan has around 20,000 km of roads, of which only 400 km are paved, and during the rains the majority of rural roads become completely inaccessible. The Logistics Cluster describes the same picture from the operating end: most roads are impassable in the rainy season, and even the fixed-wing option needs three to four dry days before a dirt airstrip is safe to land on.

That produces a short overland window rather than a year-round option. WFP frames its own planning around a brief dry season window from December to April for prepositioning food by road into remote areas, and says plainly that road transport is only feasible for a couple of months of the year in much of the country.

So the honest way to describe the choice is not "road or air". It is "road now, or air later at many times the price". If your cargo is not in the field before the window closes, the market has already decided your modality for you.

When is air the right decision, and when is it a budget failure?

Air is the right decision in three situations, and only three.

The route is physically or militarily closed and people will die inside the delay. This is the case the Logistics Cluster covers with air transport for emergency life-saving supplies to locations unreachable by road or river, provided free to organisations and prioritised through the Inter Cluster Coordination Group.
The consignment is small, high-value and time-critical, such as vaccines, rapid diagnostic tests or a pump part that has a whole water system waiting behind it. Here the air premium is small in absolute terms against the cost of the stoppage.
The response is genuinely new, an outbreak or a displacement surge in a location nobody had planned stock for.

Everything else is a planning failure that arrives dressed as an emergency. WFP's own numbers make this concrete: in 2024 it had to double the volume delivered by airdrop during the lean season, adding US$30 million to operational costs, because food was not in-country in time. That is not a logistics problem. That is a funding-timing and prepositioning problem that logistics was made to absorb.

What does the river corridor change?

The Nile and its tributaries are the cheapest bulk option South Sudan has, and they run when the roads do not. The Logistics Cluster operates an all-season river movement service on a 50% cost-sharing basis with partners through WFP, with main ports at Bor and Malakal and monthly departure schedules published for partner planning. Barges are slow, but they take heavy and bulky loads that a Caravan will never carry.

The limits are real. River routes serve a specific geography, mainly Greater Upper Nile and the corridors off it, so a barge does not help you in Western Equatoria. They are also the first thing to close when fighting moves onto the water. Plan the river as your bulk backbone where it reaches, then use road for the spurs, and hold air in reserve for the exceptions above.

For scale, the Logistics Cluster moves roughly 1,600 metric tonnes of cargo a month across air, road and barge, and handles an estimated 90% of all non-food-item aid cargo in South Sudan. If your consignment is not in that pipeline, you are arranging your own movement, and the modality decision is entirely yours to fund.

How much does prepositioning actually save?

Enough to change a country budget. WFP reports that it reduced airdrops by 70% in 2019 when prepositioning was optimised by timely funding and timely arrival of food. Set that against the US$30 million the same operation added in 2024 when stock arrived late, and the lever is obvious: the money is made or lost in the December to April window, not in the airfreight negotiation in August.

Prepositioning only works if there is somewhere to put the stock. That is the part most plans under-resource. A standard humanitarian mobile storage unit measures 24 x 10 x 5 m, giving 240 m² of floor and around 840 m³ of capacity, and the Logistics Cluster supports field storage by loaning MSUs where it can. Loaned units are finite and prioritised, so an organisation running its own dry-season push should assume it needs its own covered, raised, lockable storage at the forward site rather than a slot in someone else's shed.

The wider prepositioning logic is well proven. WFP's UNHRD network holds stock at five hubs so that relief items can be dispatched within 48 hours of a partner request. The same principle applied at county level inside South Sudan is what keeps cargo off aircraft.

What we would do with a 2026 budget line

Take a view, because the funding environment no longer rewards hedging. WFP's South Sudan operation was carrying a US$398.9 million six-month shortfall in October 2025, with all 2.7 million people it assists on 50 to 70% rations. In that environment, paying an air premium for cargo that could have travelled by road in February is not a resilience decision, it is a cut to somebody's ration.

Our recommendation for a country programme moving relief cargo inside South Sudan:

Lock the forward locations by October. You cannot preposition into a site you have not chosen.
Buy or secure storage before you buy the stock. Structure lead time, not commodity lead time, is what usually misses the window.
Move bulk on the river where it reaches, road for the spurs, and budget air only for the three exception cases.
Import to Juba, not to the field. Clearing and consolidating in-country lets you push full trucks in the dry window instead of chasing part-loads later.
Price the delay, not just the freight. A four-week slip in February is an airdrop in July.

Frequently asked questions

How much more expensive is air than road in South Sudan?

WFP states that airdrops in South Sudan can be as much as 17 times more expensive than road transport and deliver much less cargo in the same timeframe. Globally WFP puts the airdrop premium at up to seven times road cost.

When are roads usable in South Sudan?

Mainly in the dry season. WFP plans road prepositioning around a brief window from December to April, and only 400 km of the country's roughly 20,000 km road network is paved, with most rural roads inaccessible during the rains.

Is river transport cheaper than road?

For bulk cargo on the routes it serves, yes. The Logistics Cluster runs an all-season river service on a 50% cost-sharing basis with partners through Bor and Malakal, and barges carry heavier and bulkier loads than aircraft.

Does prepositioning actually reduce air costs?

Measurably. WFP cut airdrops by 70% in 2019 when prepositioning was optimised, and added US$30 million in 2024 when food did not arrive in-country in time.

How much storage does prepositioning need?

A standard humanitarian mobile storage unit is 24 x 10 x 5 m, roughly 240 m² of floor and 840 m³ of capacity. Size the forward site to the tonnage you intend to hold through the rains, not to the first convoy.