The highlight of my late June visit to the unopened and much-delayed Berlin Brandenburg Willy Brandt Airport was racing down a runway as a passenger in a tour bus going more than 60 miles per hour.

It was also one of the saddest parts of the tour.

That’s because due to technical glitches, cost overruns, corruption and project mismanagement, tour buses – not airplanes – are likely the only vehicles that will be barreling down the BER runways for quite some time.

Under construction since 2006, Berlin’s much-needed new airport was designed to serve 27 million passengers, with an initial opening target date of late 2011. That date was pushed back to June 3, 2012, and, despite trial runs during which the airport authority did tests of the baggage carousels, check-in desks and security checkpoints, and simulated what it termed “all imaginable scenarios,” a problem with the airport’s fire safety and suppression system was discovered.

With just four weeks’ notice, opening day was called off.

Since then multiple target dates for a new opening day – six or seven, it’s hard to keep count – have come and gone. Now all the company managing the project will say is that “an opening date is expected to be announced at the end of the year.”

2016 has been bandied about as the next possible opening date, but additional problems and embarrassing operational revelations keep cropping up.

In May, there was an announcement of a suspected corruption case involving bribes for the awarding of contracts.

In early June, there was out-of court settlement between the airport management company and airberlin, the major tenant at Berlin’s outdated Tegel Airport, over claims the airline felt it was due because of delays in the switchover. And at the end of June it was revealed that the engineer responsible for designing the new airport’s fire safety system was in fact just a draftsman, not a real engineer, and had been fired.

Despite – perhaps because of – the delays and the unfolding issues, there is a steady stream of people eager to pay 10 euros – about $13.60 – to go on the “BER Experience” bus tour, which is offered four days a week, in German only. (A two-hour bike tour of the airport grounds – about $20, including a box lunch – is offered on weekends as well.)

Besides showing off any progress, one reason the airport authority offers BER tours “is because it’s important that people don’t only read about the airport in the newspaper and see the reports on TV,” said Lars Wagner, Berlin Brandenburg Airport spokesman.

Tour buses stop first at a 105-foot-tall observation tower offering a bird’s-eye view of the unopened airport terminal, the unused runways, empty parking lots and assorted other facilities-in-waiting. At the bottom of the tower is an airport information center, with a scale model of the airport and a glass cabinet of souvenirs emblazoned with the BER logo.

The staff on duty the day I visited said they don’t sell many of these souvenirs to tourists and they seemed amused when I wanted to purchasing some BER T-shirts, baseball caps, tote bags, inflatable beach balls and plastic lunch boxes.

Our tour bus then drove slowly past quiet office, cargo and airport security facilities and by the railway station, where empty trains run each day to make sure systems remain working. Photo ops of the front of the main terminal building were only offered from inside the bus, but the terminal’s glass façade offered a glimpse of “The Magic Carpet,” by Pae White. The large, red work of art, one of several pieces specially-commissioned for the airport, hovers over the check-in lobby.

Out back, the bus pulled up at BER’s one A380-compatible gate, which has a jet bridge draped with Olaf Nicolai’s “Gadget,” a piece of art that looks like a string of giant pop beads and is designed to change colors to match those of the livery of the airplane at the gate.

Tour goers were allowed off the bus here and invited up a set of not-quite-finished stairs for a look at a gate area where seats were installed, but still wrapped in plastic, and ceiling panels gaped open.

“It’s not unusual for big projects like this to be over budget,” said Johann Bammann, a retired architect whose tour ticket was a gift from a friend. But delays are dragging on too long, he said, and “it’s time for the city to have a new front door.”

After a stop near the control tower, the bus made that dash down the runway, stopping to let passengers out to run around and pose for photos.

“It’s just unbelievable. I can’t understand why it’s taking such a long time to open this airport,” said Barbel Liedtke, a former Berlin-based Pan Am Airlines employee taking the tour with a friend.

“But I’m sure there are a lot people to blame.”

(My story about visiting the unopened Berlin Brandenburg Airport first appeared on USA Today)

Thanks for visiting Stuck at the Airport. Subscribe to get daily travel tidbits. And follow me on Twitter at @hbaskas and Instagram.