The lethality of the roadway stems from the unique mix of geography, the road itself, and the drivers’ disregard for the laws of physics.

The two-lane highway is barely wide enough for two cars to pass. On the inside lane, less than a yard outside your window, stands a wall of treeless rock that climbs upward in a nearly perpendicular line. A foot-high ledge guards the outside lane, behind which lies a valley floor as far as 1,000 feet down.

For the drivers, of course, that means there is virtually no margin for error: they go into the wall, or over the edge, or into each other.

The only note of caution is provided by children, who live in the impoverished villages nearby. Often as young as 4 or 5, they stand bedraggled at the bends, using flattened green Sprite bottles as flags, waving the drivers through when the way is clear.

Image A boy directed traffic last month on the Kabul-to-Jalalabad highway. In some places, children signal drivers using flattened soda bottles. Credit... Moises Saman for The New York Times

Under the circumstances, you might imagine that drivers in the Kabul Gorge would proceed slowly, crawling and craning their necks to guard against oncoming traffic whipping round the next curve. In fact, for most of history, they did.

Over the centuries, countless invading forces passed through or near the gorge on their way to the Khyber Pass. Among them were a group of 17,000 British troops and civilians, who were massacred as they beat a retreat from Kabul at the end of the first Anglo-Afghan War in 1842. Dr. William Brydon, who rode into Jalalabad on a horse, was the only European to survive.