Clogged highways, grinding poverty, high-rise apartments and collapsing infrastructure. You think it is bad now, citizens of Johannesburg and Cape Town?Brace yourselves for the worst because your cities are about to become a lot smaller and more cramped, according to an Oxford Economics Global Cities 2030 study.The study, which looks at the world's 750 largest cities, shows that city populations are to increase dramatically in the next few years, putting heavy pressure on existing infrastructure.The document states these cities will be home to 2.8 billion people (35% of the world's population).According to the UN's projections for the period between 2015 and 2030, Johannesburg's population will grow from 9.3-million to 11.5-million and Cape Town's from 3.6-million to 4.3-million.With many people migrating to Johannesburg almost daily, the study reveals the middle class will be under pressure and shrink.In 2013 Johannesburg's middle-income class was ranked 42 out of 50 in size when compared with other global cities.By 2030, Johannesburg's middle income households are expected to drop to 48 from 50.Out of the world's top 50 cities for car consumer markets, Johannesburg's will increase to $12.7-billion in value. The country's city administrators are bracing themselves for a big influx of people, which will have an impact on housing, basic services, jobs and public transport. Think-tanks and community organisations warn that cities are leaving it too late to deal with migration. At present South Africa faces a housing backlog totalling 2million units.But cities claim they are more than prepared and are pouring billions of rands into the development of special housing and transport corridors to integrate people and bring them closer to jobs, schools and other amenities.Alderman Ian Neilson, Cape Town city deputy mayor, said the city had invested heavily in infrastructure, development and economic growth promotion.He said the city was investing R750-million in alleviating traffic congestion and rolling out bus rapid transit systems."A significant portion of the budget has been dedicated to creating new housing opportunities and integrated human settlements."City of Johannesburg spokesman Nthatisi Modingoane said 120 000 people migrated to Johannesburg annually."You cannot wish urbanisation away. If we invest enough now in infrastructure we should have enough to respond to the demands."We have development strategies looking at the city up to 2040, looking at what kind of Johannesburg will exist and what kind of infrastructure interventions need to be put in place to cater for this anticipated growth," he said.Modingoane said the city had a R100-billion infrastructure investment programme "which, over the next decade, will look at bulk infrastructure and how it will cope with the numbers coming into the city".The city, he said, was creating "corridors of freedom"."The reality is that the poorest of the poor live on the periphery of the city, spending 50% of their salaries on transport. These corridors will bring people closer to the city and employment."Blessing Mancitshana, a Community Organisation Resource Centre data analyst, said though moves were under way to improve infrastructure, it was too little too late."Currently, there is not enough support, with most who come into cities ending up in informal settlements, whose densities will dramatically increase over time."To address mass urbanisation problems, cities need to think out of the box. They need to turn to new development approaches involving citizens from engagement to planning and implementation of city creation development projects. They need development based on the needs of the citizens of the cities," he said.He said the most important support required was housing."But to get housing you need land, which is difficult in both Johannesburg and Cape Town. Even if land is provided, the infrastructure support needed will involve huge rollouts of basic services, which city administrators are battling to do now. Overcrowding is going to be a huge problem."Dr Geci Karuri-Sebina of SA Cities Network, an institutional knowledge organisation for cities, said whether cities were ready for the projected population influxes was a complex question."It is not just whether infrastructure plans are up to the task of supporting the projected population influxes, but whether there is the necessary institutional, financial and human capacity to deal with cities of the future."She said infrastructure demands were not just quantitative, but were also about the qualities, use-value and affordability of that infrastructure, and for whom."Demands on infrastructure change over time. There are changing economic, social and technical demands and requirements; infrastructure has to fit purpose and context, it's not just about having it," she said."There has to be an entire societal response from building capacity to understanding what needs to be done to address the challenges and opportunities of urbanisation."..