Waterloo & City Line. The shortest of the London tube lines, it was built to convey commuters between the City of London and Waterloo station. Infrastructure Roads Many new roads were built after the formation of the Metropolitan Board of Works in 1855. They included the Embankment from 1864, Northumberland Avenue, Clerkenwell and Theobalds Roads all from 1874. The MBW was authorized to create Charing Cross Road and Shaftesbury Avenue in the Metropolitan Streets Improvements Act of 1877, the intention being to improve communication between Charing Cross, Piccadilly Circus, Oxford Street, and Tottenham Court Road. This required extensive demolition in the slums of Soho and St. Giles, with the MBW responsible for rehousing over 3,000 laborers in new-built tenements over the ten-year period it took to construct the roads. One of the most ambitious urban redesign initiatives was the building of Regent Street at the behest of the Prince Regent, who wished to build a grand boulevard linking his Carlton House in the south with Regent's Park in the north, the latter of which had reverted to Crown ownership in 1811. The new road had myriad benefits: it cleared a warren of narrow streets in Westminster in favor of a symmetrical, aesthetically pleasing street which not only relieved traffic congestion but, by providing a direct north–south route, allowed the rural area around Regent's Park to be profitably developed for residential use. Regent Street was also meant to provide a clear separation between the fashionable new development of Mayfair to the west, and the by-then undesirable area of Soho to the east. The plans, designed by John Nash, were approved by Act of Parliament in 1813, and by 1819 Nash's grand colonnaded, stucco-covered buildings were largely open for business. The street stretches from Pall Mall at its southern terminus (built closer to the Haymarket to avoid St. James's Square), crosses Piccadilly (creating Piccadilly Circus in the process), from where it curves west via the Quadrant and then runs due north, joining with Langham Place and Portland Place to create the link to Regent's Park. The area achieved its intended purpose of becoming a thriving commercial district, lined with shops of every variety to rival the quality of nearby St. James's. 1890 London had 5,728 street accidents, resulting in 144 deaths. London was the site of the world's first traffic lights, installed at the crossroads of Bridge, Great George, and Parliament Streets