HitchBOT co-creator David Harris Smith adjusts its position as co-creator Frauke Zeller, right, says farewell as the hitchhiking robot starts its journey Friday, July 17, 2015, in Marblehead, Mass. HitchBOT is beginning its' first cross-country hitchhiking trip of the U.S., in Marblehead with a final destination goal of reaching San Francisco. (AP Photo/Stephan Savoia)

With its thumb raised skyward and a grin on its digital face, the robotic creation of two researchers in Canada embarked on a hitchhiking journey across the U.S. on Friday.

The humanoid robot named hitchBOT has already caught rides across Canada and in Europe, relying on the kindness and curiosity of strangers. But this is its first U.S. tour, setting out from Massachusetts with dreams of San Francisco ahead.

Along the way, it hopes to see some quintessential American sites, including Times Square, Mount Rushmore and the Grand Canyon.

To start the journey, its creators set it alongside a road in Marblehead with tape wrapped around its cylindrical head that read "San Francisco or bust." Not long after, a group of German tourists picked it up and strapped it into their SUV with plans to take it to Boston or New York.

The kid-size robot is immobile on its own, so it gets from place to place by being schlepped around by strangers. Travelers can pass it off to others they meet, or leave it at a gas station or shop. They just leave it seated on its kickstand with its thumb raised.

Ideally, the creators hope, drivers won't leave the bot along busy roads and will charge the battery when it runs low. Otherwise, there are no rules.

"We want to see what people do with this kind of technology when we leave it up to them," said Frauke Zeller, one of the creators and an assistant professor in professional communication at Toronto's Ryerson University. "It's an art project in the wild—it invites people to participate."

HitchBOT, a hitchhiking robot, sits near the harbor waiting for its first ride as a little girl makes her way down to the water Friday, July 17, 2015, in Marblehead, Mass. HitchBOT is beginning its' first cross-country hitchhiking trip of the U.S., in Marblehead with a final destination goal of reaching San Francisco. (AP Photo/Stephan Savoia)

On the outside, hitchBOT looks like it's built for play rather than performance. It has a bucket for a body and bendy foam limbs capped by yellow gardening gloves and matching rubber boots. The whimsical attire is intentional, its makers said, to make it approachable and to deter potential thieves.

"It has a really low-tech look to it, something we dubbed the 'yard-sale aesthetic,'" said David Harris Smith, the other creator and an assistant professor in communication studies at McMaster University in Hamilton, Ontario. "The head is actually an acrylic cake-saver."

A pedestrian walks her dog and talks on her cell phone as HitchBOT, a hitchhiking robot, waits for a ride Friday, July 17, 2015, in Marblehead, Mass. HitchBOT is beginning its' first cross-country hitchhiking trip of the U.S., in Marblehead with a final destination goal of reaching San Francisco. (AP Photo/Stephan Savoia)

Designed to be a talking travel companion, the robot can toss out factoids and carry limited conversation. It can be charming and cheeky, its makers said.

So far, there are no signs of anything nefarious done to the robot, but there's also no proof. Its creators intentionally cast their gaze aside.

"We want to be very careful to avoid surveillance technologies with this; that's not what we're trying to do here," Smith said.

A GPS in the robot can track its location, and a camera randomly snaps photos about every 20 minutes to document its travels. But the team behind the robot seeks permission from people in the photos before posting them to social media, where hitchBOT has built a devoted fan base.

HitchBOT, a hitchhiking robot, waits for a passing motorist to pick it up Friday, July 17, 2015, in Marblehead, Mass. HitchBOT is beginning its' first cross-country hitchhiking trip of the U.S., in Marblehead with a final destination goal of reaching San Francisco. (AP Photo/Stephan Savoia)

More than 30,000 people follow the robot on Twitter, and dozens have posted their own selfies with it. Researchers are culling data from social media to study how people interact with a robot that needs their help, unlike traditional robots designed to help them.

Among the chief questions researchers are asking, Zeller said, is whether robots can trust humans.

During past travels, the robot has attended a comic convention and a wedding, and it had its portrait painted in the Netherlands. It once spent a week with a heavy metal band.

A car drives by HitchBOT, a hitchhiking robot Friday, July 17, 2015, in Marblehead, Mass. HitchBOT is beginning its' first cross-country hitchhiking trip of the U.S., in Marblehead with a final destination goal of reaching San Francisco. (AP Photo/Stephan Savoia)

The cross-country tour of Canada took 26 days, spanning more than 6,000 miles. As for the U.S. trip, researchers don't know how long it will take or what will happen along the way.

"We want to create something that has a bit of narrative to it, a sense of adventure," Smith said. "We don't really know what's going to happen."

Area residents gather around HitchBOT, a hitchhiking robot, as it waits for its first ride Friday, July 17, 2015, in Marblehead, Mass. HitchBOT is beginning its' first cross-country hitchhiking trip of the U.S., in Marblehead with a final destination goal of reaching San Francisco. (AP Photo/Stephan Savoia)

German tourist Quint Siess picks-up hitchBOT, a hitchhiking robot, and beings to carry it across Front Street to his car for hitchBOT's first ride as Siess' traveling companions Vicky Siess, center, and Sarah Strempel stand near Friday, July 17, 2015, in Marblehead, Mass. The tourists are not sure how far they will take HitchBOT but Boston and New York are possibilities. (AP Photo/Stephan Savoia)

German tourist Eric Vogel straps a seatbelt around HitchBOT, a hitchhiking robot, as Vogel and his traveling companions give hitchBot its first ride Friday, July 17, 2015, in Marblehead, Mass. HitchBOT is beginning its' first cross-country hitchhiking trip of the U.S., in Marblehead with a final destination goal of reaching San Francisco. (AP Photo/Stephan Savoia)

German tourist Sarah Strempel climbs into the back seat of a Chevy Suburban to take her place next to HitchBOT, a hitchhiking robot, as she and a group of her companions pickup hitchBot for its first ride Friday, July 17, 2015, in Marblehead, Mass. HitchBOT is beginning its' first cross-country hitchhiking trip of the U.S., in Marblehead with a final destination goal of reaching San Francisco. (AP Photo/Stephan Savoia)

HitchBOT, a hitchhiking robot, sits with German tourists Sarah Strempel and Eric Vogel, right, in the back seat of a vehicle as they and their companions prepare to leave Marblehead, Mass., after picking-up hitchBot for its first ride Friday, July 17, 2015. HitchBOT is beginning its first cross-country hitchhiking trip of the U.S., in Marblehead with a final destination goal of reaching San Francisco. (AP Photo/Stephan Savoia)

Explore further Hitchhiking robot travels across Canada (Update)

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