West of Caldewgate and north of Denton Holme the suburbs of Newtown, Morton, Sandsfield Park, Longsowerby, Raffles and Belle Vue developed in the late 19th and 20th centuries. The eastern side of the city centre developed in the 19th century into a more affluent area along the main A69 road. It links with the former village of Botcherby to which a large council estate was added in the mid-20th century and later still Durranhill Housing Estate. South of the city centre is the Botchergate/St Nicholas area of late Victorian terraced housing similar to that found in Denton Holme and Caldewgate. The Botchergate East area until recently had older slum dwellings. To the south west of Botchergate and St Nicholas are the former villages now suburbs of Upperby and Currock. The urban area spills over the former county borough boundary into Blackwell and Durdar in the civil parish of St Cuthbert Without. Between Upperby and Botcherby is Harraby a former village once part of St Cuthbert Without and the largest suburb of Carlisle. Harraby is subdivided into Harraby East, New Harraby, Harraby Green, Old Harraby, Petteril Bank and the Durranhill Industrial Estate. Adjoining Harraby to the south but outside the former borough boundary is the hamlet of Carleton. Carlisle is linked to the rest of England via the M6 motorway to the south, and to Scotland via the M74/A74 towards Glasgow and the north. Many trunk roads begin or terminate in Carlisle, including the A6 to Penrith and Luton (historically the main road to the south) , the A595 to western Cumbria, the A69 to Newcastle upon Tyne and the A7 to Edinburgh. The city of Carlisle is the only city in Great Britain other than London and Edinburgh with more than one single numbered 'A' road - A6 and A7 (although at one time the A5 and A6 met in St Albans). Traffic in the Carlisle area, especially at rush hour, is a significant problem and in 2012 a bypass opened to take traffic from west Cumbria heading to the M6 away from the city centre. Carlisle became a major railway centre with at one time seven different companies using Carlisle Citadel railway station. Prior to the building of the Citadel railway station, Carlisle had several railway stations, including London Road railway station.