At first, it seems like a normal traffic jam. However, things quickly take a turn for the worse, as it lasts so long that people are running out of food. Though the people in the cars are stranded near farms, they're still unable to get basic required necessities. Julio Cortázar writes:

The farms were either abandoned or the people refused to sell to them, alleging regulations forbidding the sale to private individuals and suspecting that they were inspectors taking advantage of the circumstances to test them. In spite of everything, they had been able to bring back a small amount of water and some provisions, perhaps stolen by the soldier, who was grinning and not going into details. Of course, the bottleneck couldn't last much longer, but the food they had wasn't the best for the children or the old lady.

Perhaps it's the lack of food that causes things to break down so quickly. Everyone forms their own groups in the traffic based on who they're near and work to take care of their own communities. As one day becomes two and then many, the people—identified by the types of cars they're driving in—begin to form relationships and patterns.

No one is sure why the traffic jam is happening; news comes from people who roam, but the engineer knows that he can't trust it. There are all kinds of wild theories but none that account for having to stay sitting on the highway for days. The news is so obviously fake and uninformed that it enrages others. For example:

Sometimes a stranger would appear, someone coming from the opposite side of the road or from the outside lanes on the right, who would slip between cars to bring some news, probably false, relayed from car to car along the hot miles. The stranger would savor the impact of his news, the slamming of doors as passengers rushed back to comment on the events; but after a while a horn, or an engine starting up, would drive the stranger away, zigzagging through the cars, rushing to get into his and away from the justified anger of the others. And so, all afternoon, they heard about the crash of a Floride and a 2CV near Corbeil—three dead and one child wounded; the double collision of a Fiat 1500 and a Renault station wagon, which in turn smashed into an Austin full of English tourists; the overturning of an Orly airport bus, teeming with passengers from the Copenhagen flight. The engineer was sure that almost everything was false.

So they sit without knowing why or when it is going to end. This only further cements their need for local communities and rituals to get through the time.

The boy in the Simca wants to meet a girl but knows that he can't because of the divisions between the communities made up of groups of cars. The situation is extremely desperate at this point, but human emotions still rule the hearts of the people waiting for the road to clear. Cortázar says:

it was unthinkable with this cold and hunger, not to mention that the group up front was openly hostile to Taunus' because of some story about a can of condensed milk, and except for official transactions with Ford Mercury and Porsche, there was no possible contact with other groups.

So many occurrences are rumors; there's a story about a can of condensed milk but no actual information on what happened. The groups are formed enough that there are official transactions. There's a whole new society forming on the road—until the traffic...