From the press release:
For the first time, one team will be booted at the start of the trek, and racers will have to tackle the Switchback, a new twist that sends teams back to one of the series' most challenging "roadblocks." Executive producer Bertram van Munster said the racers will set off from the Los Angeles River, then first head to Tokyo to complete several zany tasks.
Let's see what the roadblock possibilities are for the countries visited this time around (descriptions from wikipedia):
"in the Roadblock one team member had to walk through a pit of tigers."
Not very exciting, but nerve wracking for the racers.
Bo Tor, Ao Luk Thailand
"The Roadblock was to paddle a kayak with the team and their luggage to a nearby cave with snorkling gear and their next clue."
"one team member had to venture into a cave full of bats and retrieve their next clue from inside. "
Chiang Mai Thailand
"The Roadblock was to wash chalk markings off an elephants back until the judge was satisfied."
Boring and old hat. Wouldn't delay teams very long (a plus) and can be set up anywhere (another plus). Possible but I hope not.
Ho Chi Minh City Vietnam
"The Roadblock was to drive the other team member in cyclos through a marked path, over a ferry and to the pitstop."
Doesn't sound infamous to me.
Hoi An Vietnam
"The Roadblock was to use a fishing platform to raise a net out of the water with the clue dangling underneath."
Even less infamous.
"The Roadblock was to catch 25 eels and place them in a container."
This one could be fun and could be set up in any number of places. Possible.
Burj al-Arab Dubai
"The unaired Roadblock involved one team member to buying nuts in the market and delivering them to a ship."
No. If it wasn't worthy of being aired the first time, it's not infamous (except among us handful of fanatics).
"one team member had to unroll large bales of hay to find clues rolled up inside them. Out of 270 hay bales, 20 of them had clues."
Very infamous and a strong candidate. There are no doubt farms not far from Stockholm where it could be recreated. The only drawback is that it could cost a team several hours and I doubt TAR would do this unless a bunching point is present on the next leg. And the ferry ride to Talinn, Estonia could easily qualify as a bunching point.
Seasons 7 and 8: Didn't visit any Season 15 countries (except USA)
"The Roadblock required one team member to make a ceremonial feast for monkeys at the temple and give it to them during an annual festival. Following a demo that has already been set up. When it is finished and offered it to the monkeys, they would get their next clue."
Eh. I doubt it.
Fujiyoshida, Yamanashi Prefecture Japan
"The Roadblock required one team member to ride on three extreme rides in the Fujikyu Highland Amusement Park in the following order: The Pizza, Dodonpa, and Fujiyama. While riding the rides, they had to look for a man holding a sign. Upon completion of their third ride, they had to tell the park manager what was written on the sign to receive their next clue. If they didn't see the sign they would have to go on all three rides again."
They are already going to an amusement park in Stockholm. I can't see them going to one in Japan. Possibly they will recreate it in Stockholm, but if I start taking roadblocks from one country to another then this search gets way too complicated.
"In this leg's Roadblock, one team member to choose a Vietnamese bicycles with a basket of flowers and sell enough to make at least 80,000₫ (dong VND - approximately USD $5). Whatever the money earned, they were allowed to keep the money they made."
Not very thrilling or memorable.
Ha Long Bay Vietnam
"This leg's Roadblock one team member to use a mechanical ascender to climb 90 feet (27 m) the sheer face of the rock, receive the clue and then rappel down. "
This was the one I thought of first. However, it would require travel time there and back. It was also grueling physically and TAR has really shied away from that in recent seasons. So, I doubt it.
Season 11: Didn't visit any Season 15 countries (except USA)
"one team member had to complete a single vault over a watery, muddy ditch (known as fierljeppen) and successfully touch both feet to the marshy grass on the opposite side in a regional sport known as ditch vaulting in order to receive their next clue."
Another very strong candidate. It can be set up anywhere that there's a swampy creek and doesn't require much in the way of expensive equipment. It also has a lot of pratfall humor and TAR has done that a couple of times each season recently.
"This leg's Roadblock required one team member to put on a hat and gloves as local cabbies do and transport a Japanese couple five miles through a maze of confusing, often one way streets to a specified address (the Osaka Central Post Office (Japanese)). They could not invite a local to lead them or join them in the car and the couple could not help them. Upon arrival at the correct address, the couple would hand them their next clue. However, the drivers would also have to make their way back to their teammate before they read what was inside."
Possible. It was challenging for the racers, but not that time consuming. It could be done in any Japanese city. I don't think it qualifies as infamous though.
Angkor Wat Cambodia
"In this leg's Roadblock, teams had to go into Angkor Wat and find an Echo Chamber where they had to beat their chest to hear the echo. They could then pick up a stone frieze displaying their next clue on the reverse."
Doubtful. It would require travel from Phnom Penh and it wasn't that memorable the first time.
"one team member had to put a propeller on a traditional Thai long-tail boat to receive their next clue."
No. Way too simple to be infamous.
I think it comes down to either the hay bale unrolling in Sweden or the ditch vaulting with pitchforks in the Netherlands. Since the hay bale roadblock went on for over 8 hours for Lena and Kristy in season 6 and they didn't finish it (Phil had to go there to eliminate them), I think it's more infamous. I'll guess that it's the hay bale roadblock.