I love the idea of the Humana pedal bus, 20 of which were on the ground to be used by delegates to the Republican and then the Democratic conventions this year. The rhetoric was polluting host cities Tampa and Charlotte, but not these overgrown bicycles, or bus-cycles, which can seat up to eight passengers (six of whom pedal, one of whom steers). At the conventions, they made pre-set trips in a loop that included the convention centers and downtown.

In Tampa, the pedal buses covered 541.7 miles and gave 1,250 rides. That resulted in 595 metric tons of avoided greenhouse gas emissions. The Democrats appeared to have been a bit more enthusiastic about the pedal bus: there was better weather and 1,333 rides. Mileage covered more than doubled to 1,307. And avoided climate gas also was up sharply to 1,438. To be fair, the Republicans didn’t have access to the buses for the entire event, because as you recall Hurricane Issac roared through Tampa and the program was temporarily shut down.

All told, the participants downed 6,800 glasses of water and ate 2,100 pieces of fruit, which was probably much better for them than the rubber chicken at the convention centers.

Ordinarily you’d think of a bus as too heavy to pedal, but this is a lightweight wonder (just 525 pounds) with a fiberglass nose and rear fenders, and a hardtop made of aluminum and Lexan. The buses are a collaboration between sponsor Humana, a Kentucky-based health care company, International Surrey Company, and Missouri-based Craftsmen Industries, which made them.

This would just be a feel-good story, but for the fact that the buses will continue in service, with the cities of Charlotte and Tampa getting to keep five each. Here's the Tampa donation, on video:

Karen Kress, director of transportation and planning for Tampa Downtown Partnership, said the city “regifted” the pedal buses to her nonprofit. “We’re still figuring out how to use them,” she told me. “Our idea is to use them to help people get around downtown, with a leisure focus. We have a 15-foot wide RiverWalk in Tampa, and we were thinking of using the pedal bikes to give guided tours. We’re hopeful that if that’s well-received, they can eventually go into regular downtown circulation.” A few liability hurdles remain, and some city codes will have to be changed to get the pedal bikes into regular service.

Kress says the biggest learning curve with Humana pedal bikes is getting used to the pedal arrangements. “The pedals are not independent, so you go along with whoever is pedaling the fastest,” she said. “But it’s a minor thing. We’re excited about this, and think it will be welcomed by the community.”

Mayor Anthony Foxx of Charlotte says the buses are a great way to experience his center city “while getting some exercise at the same time.” And from what I saw on TV, exercise is exactly what some of these delegates need.

I wondered if anybody else had run pedal buses, and lo and behold they had! The most popular form is the bike bar or party bus. According to the Tampa Bay Times, “Invented in the Netherlands, the pedaling party buses can be seen in Chicago, Austin, Texas, Denver, Savannah, Georgia, and Milwaukee, with passengers facing inward around a bar.”

In Denver, a lucky few in 2011 were able to ride on a wonderful combined bar and people mover called the Pedal Hopper. That's it at right. Yes, you drink and drive, with beer kegs on board no less. The enterprise was well received, but now the website is down and the Pedal Hopper appears to be no more. The Pedal Hopper, reports BikeDenver, was “essentially a roving pub powered by pedaling patrons seated around the perimeter of the bike, while one person stands and ‘tends bar’ in the middle.” The driver stays sober, of course.

In St. Petersburg, Fla., open container laws mean they don’t let you drink alcohol on board the party bus. You get blotto anyway, because the bus — capable of carrying 16 passengers, plus the driver — travels from bar to bar.

A less alcohol-soaked concept (at left) is the pedal vehicle that serves as a school bus in Holland. Sold by the De Café Racer company, it’s designed to be moved by eight 4- to 12-year-olds, with electric assist on the hills. It can reach the heady speed of 10 mph. There are also more stylized forms of the pedal school bus in England, in which the kids carry a cardboard bus — and this alert drivers as to what they're doing.

These people movers have precedents. We have to go way back in history to find Leonardo Da Vinci’s human-propelled vehicle, which was far less benign than a school bus — it was, in fact, a prototype tank (right), moved by combatants turning cranks. He told the Duke of Milan in a 15th-century job application, “I can make armored cars, safe and unassailable, which will enter the close ranks of the enemy with their artillery, and no company of soldiers is so great that they will not break through them.” Alas, the design had major technical flaws and never would have brought shock and awe to early battlefields.

Jim Motavalli ( @jmotavalli ) writes about cars, technology and the environmental world to anyone curious enough to ask.

The pedal bus: Carrying the party faithful, and party hoppers too
These pedal buses saw action at the Democratic and Republican conventions. But this unique form of human-powered transportation is more often either a beer-soak