Bill Lorenz of the International Organisation for Migration (IOM) is keeping a diary for the BBC News website as he helps thousands of Sudanese trek home to Raga in the south-west, following a deal to end a 21-year war.
He is transporting the most vulnerable on trucks through forests and swamps in a race against time, as the heavy July rains are due.
Monday July 4th
At last! The hold-up over fuel is now over. But there is a new problem. One of our big six-wheel trucks broke down trying to rescue the truck stuck in the marshes last week.
We've had to tow it back to camp. And I am not sure how or when this one is going to get fixed.
We really could do with more resources. More trucks. More land cruisers. More motorcycles... The latter are our lifeline. I don't know what we would do without them.
They follow the trucks and report back on problems. They go up the road to see how far the road cutters have gone. And they've had to go back to Tambura for spare parts flown in from Nairobi.
The good news is that 150 people have moved 20km up the road this morning to Kuru.
Today, together with the elders, we started a new system of identifying the most vulnerable among the group. We need to have fewer people on the trucks.
We gave tickets to those who really can't walk so they could board the trucks. Most of the people moved today were blind or crippled.
But this whole experience has made me think. How does one define vulnerability?
It's easy when there is an elderly blind person or a mother with a small baby. But what about their family?
Do you separate them or keep them together when you know that means losing places for others who can't make the journey. Whatever the definition - it's a moral dilemma.
It is hard to decide who should be given a lift in the trucks
For the elders, it seems easier. A 12-year-old sibling of a baby was fit to walk. So he walked.
As the trucks leave, the last two kilometres of road to Kuru are being cleared. There are 115 men in the advance group. Fifteen men mark out the route and two teams of 50 hack the trees.
The end result is a road three to four metres wide. Just enough for the trucks to pass.
I am told work has already begun on the next road - from Kuru to Yakap, including the building of the two bridges before Yakap itself. This is where we will be headed in two days to set up camp.
We are doing well for food. Along with the new fuel supplies that arrived at the weekend, there were three rather scrawny chickens for us to eat.
Everyone here keeps chickens. It's amazing. I use pieces of soap to trade for eggs. One piece buys four eggs.
But today, I give a piece away for nothing. A little girl who suffers from epilepsy has come to eat lunch with us.
Since last week when she grabbed my hand and demanded "sweetie", she has come every day for food. I give her mother some soap to wash her with.
In some ways, things are getting easier. Now we are getting closer to the savannah, there are fewer mosquitoes. It's drier, cooler weather. I even need a sleeping bag at night.
The best news - there are no snakes. Or at least, I haven't met any for a while.
Wednesday 29 June
I am awoken at 0400 by a heavy, rhythmic pounding.
It takes a few seconds before I realise what it is. The women are crushing maize and sorghum to make flour.
It's easier to carry food in this way when one is walking hundreds of kilometres through dense forest and swamps.
It's 52 days now since we joined the group, who fled their homes in Raga four years ago to escape Sudanese government forces.
We are going through the forests, because the main routes are too dangerous due to minefields and collapsed bridges.
The journey seems relentless. But I am happy today.
I am told the terrain changes 12km ahead into something more savannah-like. It should be easier for the people to move and less problematic for the lorries to operate.
News has got back that the advance group has opened the first 15km of the 42km of road we still have to travel before we get to the next camp at Yakap.
Some 6,000 people are currently walking the 400km
Last night we had a meeting with the community elders. We told them more able-bodied people needed to walk as the four lorries we have are really for those who aren't able to.
The message seems to have got through. This morning, lots of people left on foot.
Maybe it was because an old blind man with a cane, led by an eight-year-old boy, went around the camp last night telling people there would be no more airdrops of food supplies, so they might as well start walking.
He's nicknamed "the minister of public information" and his joke made everyone laugh.
Stuck in the mud
This morning I hear from two of our staff stuck in marshes further behind us. They have the new fuel supplies.
Without it, we won't be able to move anywhere. I am worried about them but reassured by the good radio contact we have.
They tell me that they have had to rebuild one bridge and cross two swamps to be able to reach the marshy patch. Now they are trying to fill the marsh with rocks and debris so their lorry and a land cruiser can cross it.
The news concerns me for other reasons too.
Since leaving Tambura in May, the displaced people have built 200km of road as they travel, but now the rains are making it impassable.
This is our logistical pipeline. I really hope that fuel arrives tonight.
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