"I've been scared, I don't mind telling you."
The highway stretches through deserted but dangerous mountains
Chris Humphries is honest about living and working in one of the most dangerous parts of Afghanistan - Zabul province, where attacks by the Taleban are a regular occurrence.
He admits he hasn't told people back home exactly where he is.
"I don't want my family to worry."
So do they have any idea of his location?
"No," he laughs. "They think it's part of Iraq."
The reason Mr Humphries is there, inside a fortified camp in the middle of the desert, is that he works for US construction firm Louis Berger.
It is responsible for a $250m project to rebuild the nearly 400km (250-mile)-long Kabul to Kandahar highway through southern Afghanistan.
It is almost complete. But despite employing hundreds of armed guards, Louis Berger has lost over 30 staff during the 18-month project, most to attacks by militants.
Mr Humphries oversees a particularly isolated 85km stretch of road, surrounded by empty desert and mountains.
And he and fellow American Mike Jennings, a security specialist, are the only Westerners living there.
Although in this most volatile province, the construction camp is also used occasionally by US soldiers.
Much of the remaining work involves replacing sections finished in a hurry, in response to pressure from Washington to get the road open by December last year.
It is no surprise that it has been dubbed the George Bush highway.
The White House was desperate to have a major US-funded project in Afghanistan to talk about, and to head off criticism that its reconstruction efforts here were stalling.
"It's the most political project I've ever done," says Jim Myers, head of Louis Berger's Afghan operations.
The road is now making a big difference though.
"It used to take two or three days to get to Kabul, now it's just a day," says Hamidullah, a truck driver about to start another journey from Kandahar.
Yet roads are just as political an issue inside Afghanistan, especially as elections approach on October 9.
But in the north, you will often hear people complain that all the US investment in roads has gone south, because that is where President Hamid Karzai is from.
The project has highlighted concerns about the region's future
Perhaps hoping to dampen such criticism, the Afghan leader made a point of travelling to open a new road project in the north last month.
He was then attacked for using a government trip for campaigning purposes.
There is another concern now, according to Jim Myers - that US funds originally committed for Afghan road-building are being diverted to Iraq.
But Patrick Fine, director of the US Agency for International Development in Kabul, which provides the cash, rejects this.
"That is just not an accurate characterisation either of the way the US government allocates funds, or of any reality," he says.
The US will see through all the projects it has committed to, he says.
"I would challenge you to find any place where roads are being built faster under the conditions in which we are working here," he adds.
And if, as everyone assumes, President Karzai wins the election, one of the things Afghans will be hoping for is that he can speed up road and other reconstruction projects across the country.
But as always, every action has consequences.
With the Kabul-Kandahar now largely open, a new problem has emerged - speed.
Now that drivers can cruise at over 120km/h for much of the way, there has been an upsurge in accidents.
"We've seen some horrific injuries round here," says Chris Humphries.
In response, he and Mike Jennings have spent their own money to build a roadside clinic. They pay for all the drugs and the doctor's salary.
What is not clear, though, is what will happen to the clinic when the road work is finally done.