For months, it seemed as if Abu Dhabi were slowly emptying out. Day after day, the traffic was a little lighter, the crowds a little less intense. Driving around the town, which often is nightmarish, was easy.

It peaked last week, when roads were nearly empty in the middle of the day.

But now it’s over. It’s as if someone parachuted 500,000 people and 100,000 cars into town overnight. It’s quite amazing.

We have explanations for what happened.

First, nobody wants to be in Abu Dhabi or the UAE in the summer. If they can help it, they go someplace cooler. Europe is preferred.

And those who “can help it” include a big chunk of the 1 million Emiratis who live here, often quite well, thank you. Many of them go to Paris, to London … they get up and leave for destinations were the weather is cooler and the scenery is verdant.

Also, many Westerners seem to work jobs that run about the length of the school year — with summers off. Certainly, all the schools are closed, and the university professors and kindergarten teachers we might know have all of July and August off … and they pack up and leave, too.

Second, last week was Eid Al Fitr, a major and lengthy holiday. It lasted all week, actually. As mentioned in an earlier post, every government worker had off nine consecutive days, including all of last week, and The National did a story about the rush to the airport for those who wanted to rejoin family (Eid Al Fitr is a big family holiday) or just wanted to take advantage of the nine straight days off.

(Oddly, to an Occidental mind, the nine-day break at Eid Al Fitr was not announced until a few days before it happened. The lunar-calendar event depends on the sighting of the moon, and it was only a few days ahead of the start of the long break that workers learned of it, prompting a rush for the airport.)

Abu Dhabi, then, was a ghost town. When driving to Al Ain last week, about 100 miles east of the capital, there were times when the three-lane highway (each direction), which bends gently, showed no observable cars ahead of me … and none in my rearview mirrors, either.

It was almost like living in some sort of post-apocalyptic world. Just me and a handful of others, knocking around the desert.

And then it all ended. Today.

I believe many school years began today, Sunday. (Which is like Monday in the West.) Many, many folks who had been on extended vacations, both Emiratis and expats, came back … and today, traffic was up about 500 percent. It was back to clotting at every major intersection, forcing drivers to wait two or three green-light cycles before being able to get across a street.

This was the Abu Dhabi of the spring, fall and winter. Crowded. Almost too busy.

It made for a major adjustment. From where we live to the Corniche … maybe 10 minutes yesterday … and 30 minutes today. Something to take into account.

Abu Dhabi and the UAE … back in business.