London started its first major bike hire scheme   on July 30th. Transport For London (TFL), the agency responsible for moving people around England's capital, put 5,000 bicycles in 400 different places around the city.  The idea is to cut traffic, reduce pollution and provide a greener way of getting around London's streets. The scheme had a few small problems on its first day as people could not lock the bikes properly once they had finished riding them. As a gesture of goodwill, London Mayor Boris Johnson announced all rentals   on the first day would be free of charge. The bikes are available for free for the first 30 minutes but costs go up sharply since then. Renters have to pay $1.60 for the first hour and $78 for 24 hours. The bikes are clearly designed for very short trips. TFL says it sees a "cycle revolution" happening in London. It predicts there will be around 40,000 new cycle journeys every day on the rental bikes. Mr. Johnson says he wants to see a return to the turn of the 20th century, when 20 per cent of journeys in London were made by bicycle. The scheme has received a lot of positive feedback   in the first two days.  Many Londoners believe it is a great alternative   to London's overcrowded and overpriced trains and buses. One person, Andy Clark, told the Reuters news agency, "It's a great idea. I've seen it operating in Paris and Barcelona and thought why don't we have one?" The Londonist Blog said the bikes were very strong and were "designed to bear a beating from both careless cyclists and drunken people". What's the main idea of the passage?
London starts a new bike hire scheme. London needs better measures to cut traffic. London encourages people to buy bikes. London decides to protect the environment.