Four-time Boston marathon champion Bill Rodgers rose up in a cherry picker on Boylston Street on a chilly Thursday morning to reveal new banners celebrating the 108th Boston Marathon, which 20,000 people will run on April 18, according to the Boston Athletic Association. As the cherry picker rose, Rodgers, 56, said the banners are “beauties and can’t go wrong.” The cherry picker jutted abruptly to the left, and Rodgers clutched the edge of the banner, asking “Do I look scared up here?” John Hancock Financial Services provided 800 of the brightly-colored banners that will line the streets of Boston and the surrounding area, said Amy MacDonald, owner of the Heritage Flag company, which has installed and produced the marathon’s banners in past years. “They’re a sign of spring,” she said. The Hill Holliday agency designed the banners, which feature three designs, each representing the different divisions of the race. A banner for the women is purple and yellow, the men’s is blue and white and the banner for wheelchair racers is fuschia and green. Each banner has an athlete in motion and “Boston Marathon” on it as well the John Hancock logo. This year, the top competing women will be given a 29-minute head start, according to the BAA. “I think it’s wonderful – women have always been lost in the crowd of men,” Rodgers said. “This gives women a chance to show their strength and capabilities.” Boston is following the lead of the marathons in New York, Los Angeles and London. “Boston has always kept abreast with changes occurring in sports. This is the number one marathon in the world,” Rodgers said. Women’s participation in the marathon has increased exponentially, he said, and currently about half of the runners are women. “Boston has always been at the forefront,” he said. “Margaret Okayo set the women’s record [2:20:43 in 2002] here in Boston. “The marathon is a commitment,” Rodgers said. “I got a call from one of my buddies this morning. He and his friends were going to go running before work at 6 a.m.” Some of the most impressive athletes run marathons, he said, because they often work full-time. “I was a teacher,” he said. “Being a professional athlete was easier. I chickened out!” On his intentions to return to the Boston Marathon, Rodgers said, “I do intend to run again, in my mind and heart.” Rodgers’ training for this year’s marathon was hampered by an injury last August. Marathons take at least six months to a year to train for, he said. “I still run competitively in the ‘masters over 40’ in a half-marathon,” he said.