Five large black taxicabs are making a cross-country jaunt. They’re halfway from New York to San Francisco and they’re stopping in Des Moines this weekend. Terry Faucher is a cab driver from London. He and four other cabbies are making the four-thousand mile drive across the U.S. to act as tour guides for their hometown in England. Faucher says they’re promoting London by driving around in a grid pattern and offering people free rides in actual London cabs. The cabs are scheduled to arrive at Des Moines City Hall on Sunday at 9 A.M. Faucher says the cabs themselves are rolling billboards, inside and out. Each cab has a different theme to promote London, including its pubs, parks, theaters and the Underground, London’s subway system. He says the taxicabs themselves are very distinctive. Faucher, who’s 42, says he spent four years in training to become a London cabbie, earning what he says is the equivalent of a university degree in taxi. Faucher and the other four were chosen from among thousands by English passengers as the best cabbies in London to be ambassadors on this venture.