Making a trip across the United States into an adventure isn’t easy these days — unless your idea of adventure is fighting through the crowd at airport security or navigating transfers at half a dozen Greyhound bus stations. The simplest solution is to adopt an improbable, romantic or slightly ridiculous mode of transportation.

This approach has served well those who have traversed the country on roller skates, unicycles and Segways. (That doesn’t count this guy, who traveled in a lawn chair hefted aloft by weather balloons; he only made it from Oregon to Idaho.)

Now joining the ranks of those indefatigable road-trippers are 19 men and one woman from the Netherlands, who recently followed historic Route 66, from Chicago to Santa Monica, Calif., aboard Velosolex mopeds.

The group, which had a host of Dutch and American sponsors, left from the Art Institute in Chicago on September 27 and arrived in California on Wednesday. Along the way, the riders seem to have encountered the usual bits of road-trip Americana: the world’s largest rocking chair, a teepee motel and a suspect meal at Taco Bell. A diary of the tour, which also raised funds for three different charities, is here.

Essentially a single-gear bicycle with a motor mounted on the front wheel, the original Velosolex was a popular and cheap form of transportation in the mid-20th century. Part of the appeal, of course, is the machine’s simplicity — the 49cc two-cycle engine assists the rider up to a speed of about 20 miles an hour, and the engine is engaged via a hand lever in front of the handlebars.

The current Velosolex, which is manufactured in France, is based on a design dating back decades. After several ownership changes, production ceased in 2002. The brand was revived in 2005, and the mopeds are now distributed in the United States by Velosolex U.S.A., a New Jersey-based company. Another company sold a very similar bike in recent years.

The Dutch Velosolex group isn’t the first to have crossed the country on moped. But it’s not easy to find a truly novel way across the country. (There are hundreds of people who have walked, jogged or run.) My suggestion for a rambunctious adventurer? A pogo stick journey, from Pensacola to Pismo Beach.