

Republican Presidential candidate Herman Cain stopped next to his campaign bus to be photographed with two policemen during a campaign stop to launch his 'Economic opportunity zone plan' in Detroit, Mich., in October. Rebecca Cook/Reuters
Warlord-turned-pastor and politician Prince Johnson gestured to supporters out the window of Liberian President Ellen Johnson Sirleaf's bus after staging a rally on the final day of campaigning, in Monrovia, Liberia, in November. Rebecca Blackwell/AP
US Republican presidential candidate and Texas Governor Rick Perry stepped off his bus to make a campaign stop at Dave's Restaurant in Charles City, Iowa, on December 18. Jim Young/Reuters
The tour bus of Sarah Palin, former GOP vice presidential candidate and Alaska governor, was parked outside Independence National Historical Park in Philadelphia in June. Matt Rourke/AP
Sarah Palin, former governor of Alaska, greeted people outside Fox News headquarters before boarding her 'One Nation Tour' bus with her daughter Piper (l.) in New York. Palin was on a tour of historical sites between Washington and New England in June. Gary Hershorn/Reuters
Kenza Drider, wearing a niqab, a French Muslim of North African descent, was surrounded by the media as she exited a bus to announce her intention to be a candidate in France's 2012 presidential elections, in Meaux, France, in September. In France, individuals must have the signatures of 500 mayors in order to run in the presidential elections. Charles Platiau/Reuters
The bus carrying US Republican presidential candidate and Rep. Michele Bachmann (R-MN) drives into Orange City, Iowa, on the first day of her 99 county tour of the state on December 16. Jeff Haynes/Reuters
Michael Steele, then-chairman of the Republican National Committee, spoke with Florida Sen. Mike Haridopolos (l.) during a stop at Osceola Heritage Park in Kissimmee, Fla., in 2010 as part of the 'Fire Pelosi Bus Tour,' which traveled to over 100 cities in the United States. Ann Hermes/Staff
The bus used by US President Barack Obama to travel around Minnesota, Iowa and Illinois is pictured on the tarmac of Minneapolis-St. Paul Airport in August. Jason Reed/Reuters
Manuel Baldizon, presidential candidate for Libertad Democratica Renovada, smiled as he took a bus in Guatemala City. Baldizon, who picked up 23.3 percent of votes in September's first round run-off, started a '30-hour trek' to visit markets, neighborhoods and squares to promote his candidacy in November. Jorge Dan Lopez/Reuters
Democratic presidential candidate Sen. Hillary Clinton (D-NY) and her daughter, Chelsea (c.,) spoke with 18-year-old Ben Coleman (in white shirt) as they met with young undecided voters aboard Clinton's campaign bus before a campaign event in Durham, N.H., in 2008. Mike Segar/Reuters
Supporters of Haitian presidential candidate Michel Martelly waved posters from a bus in Port-au-Prince in 2010. Keith Bedford/Reuters
Democratic Presidential candidate former Sen. John Edwards waved farewell in Des Moines, Iowa, at the start of a bus tour around the state in 2007. Andy Nelson/Staff
Peru's presidential candidate and former President Alejandro Toledo waved to the crowd during a rally on his campaign bus in the shanty towns of San Juan de Lurigancho in Lima in March. Mariana Bazo/Reuters
View of the bus driver on the campaign bus of Democratic Presidential candidate Dr. Howard Dean as they drove through Kansas in 2003. Andy Nelson/Staff
A public bus displayed a poster with a portrait of popular Conservative candidate Mariano Rajoy in Pamplona, Spain, in November. Alvaro Barrientos/AP
Republican presidential candidate Sen. John McCain (R-AZ) stepped off his campaign bus for a book signing into a large crowd of supporters in Cincinnati, Ohio, in 2000. Stephan Savoia/AP
Election officials rode in a bus with ballot boxes from a closed polling station en route to a counting center in Cairo on December 6. Khalil Hamra/AP