to freeway standard ("M" freeways), while most are generally sealed and of reasonable to high quality. Urban freeways In the 1950s and 1960s, private ownership of cars increased, and newer suburbs were created beyond the tram and rail networks. This eventually led to congestion on the road network between the suburbs and the CBD. As Melbourne extended, planners and politicians decided that the roads could no longer cope. The 1969 Melbourne Transportation Plan called for construction of an extensive network of freeways. The Victorian government were advised by American highway planners and it sent its road engineers to the US. The resulting network is the most extensive in Australia. Unlike many American cities, Melbourne had an extensive public transport network and opposition to the plan grew, arguing that money is better spent on public transport upgrades, particularly to areas of Melbourne poorly served by public transport such as the outer east. This led to clashes including the showdown in 1977, over the plan to build the F19 freeway through Collingwood and Fitzroy. In the fiercest battle, groups of protesters such as the Carlton Association barricaded Alexandra Parade. Although the resulting Eastern Freeway was finally built, many road projects were shelved and freeway construction was suspended until the mid-1990s. One notable exception was the South Eastern arterial, which was constructed under the John Cain Labor government. The party had a policy of no new freeways, but the road was desperately needed to link the existing Mulgrave and South-Eastern freeways. The result was a multi-lane highway with traffic lights at several major intersection. This created traffic congestion, the road being dubbed Melbourne's longest carpark. It was eventually upgraded to freeway standard, and incorporated into the Monash Freeway. Freeway construction resumed in the 1990s, with the construction of the Western Ring Road, CityLink and others. Most of these freeways are expected eventually to join in a continuous and extensive network. Most recently, the M11 Peninsula Link was opened in 2013, to join the 2 halves of the unfinished Mornington Peninsula Freeway. Impact of road transport in Melbourne Where they were built, population growth followed, as Melburnians moved away from the crowded inner and middle suburbs to cheaper outer suburbs; for example, Monash Freeway and Mornington Peninsula Freeway led to explosive growth of population in the south east and the Mornington Peninsula. The completion of Western Ring Road spurred housing growth in the western