Alongside the economic shift from west to east, the early 21st century may also be remembered for its rapid urbanisation. By 2030, according to UN estimates, 60% of the world’s population, or 5 billion people, will live in cities, putting unprecedented pressure on city infrastructures.

There is little surprise, therefore, that in both developed and developing cities, transport networks – the arteries that transmit the daily pulse of workers from home to workplace and back again – are clogging up. Most large cities suffer daily gridlock, despite the fact that in North American urban areas, roads and car parks can account for up to 60% of the cities’ surface area. Cities in developing countries, many of which have grown faster, have similar or worse problems.

Improving inner-city transport has never been more important and levels of investment are slowly starting to rise, particularly in Asia, but also in Latin America where new thinking on transport has started to have a positive impact. In 2011, half a dozen developing country cities, including Bangalore (India), Algiers (Algeria), Xi’an (China), Almaty (Kazakhstan) and Lima (Peru), opened inner-city metro lines.

In the US, a growing lobby is calling for a 1930s-style New Deal stimulus package with public transport investment at its heart. In 2011, a number of urban transport schemes were approved in North America, including one in the US city of Cincinnati, Ohio, and another in the Waterloo region in Canada’s province of Ontario, which both committed to mass light-rail projects.

The Chinese model

In China, where an average of 18 million people are moving from the countryside into urban areas each year, levels of public investment in mass transport have already risen sharply. “With over 150 cities with a population of more than 1 million, China particularly needs mass-transit solutions,” says Chris Porter, a principal at Cambridge Systematics, a consulting firm specialising in transportation investment and planning. China’s infrastructure projects are estimated at more than $1500bn in the next five years. Many Chinese cities have also worked hard to encourage non-motorised transport in city centres, for example, by promoting bicycle greenways and pedestrian areas.

China is also using mass rail transit to create mega cities with populations of more than 40 million by joining existing urban centres through high-speed rail networks. For example, cities in the Pearl River delta such as Guangzhou, Shenzhen, Dongguan and others will be joined by 150 major infrastructure projects to create a city that will eventually account for about 10% of China's GDP. Some 29 rail lines accounting for 5000 kilometres of track will be added, cutting journey times considerably.

In northern China, another mega-city project to create the 'Bohai Economic Rim' involves linking cities including Beijing, Tianjin and their satellite areas. The high-speed rail link between Beijing and Tianjin has already been completed, cutting the 120-kilometre journey time to just 30 minutes.

Planning experts say this level of investment in urban transport schemes is vital to sustain current levels of urban development. Mr Porter says: “Transport investment is very important for development, in fact it is fundamental. People need to be able to get to jobs, and employers need access to a labour force. Improving transport effectively increases the size of the labour pool.”

Waterloo's added value

Research by the US Transportation Research Board concluded that road-based travel breaks down when more than 2000 cars per hour attempt to travel in a single lane. In striking contrast, a modern light rail system can move more than 25,000 passengers per hour – the equivalent of an 18-lane highway. Making the case for large-scale public investment in mass-transit schemes, particularly expensive inner-city rail systems, during a period of sustained global economic uncertainty may not be easy, yet the compelling arguments are being heard.

Canada’s Waterloo region looked at several European and North American transport systems before confirming its decision in 2011 to build a mass light-rail system. “We looked at numerous cities for examples of what to and what not to do,” says John Yung, CEO of the region’s investment promotion agency Canada’s Technology Triangle. Among the transit systems Waterloo looked at was London’s Docklands Light Railway, which carries more than 100,000 people each day and has recently been extended ahead of the 2012 Olympic Games being held in London.

Mr Yung says the decision is already having a positive impact: “The prospect of future rapid transit is already affecting development. The total value of building permits issued in 2010 for new construction in the Waterloo region was $1.5bn, an increase of 65% from 2009 values – the highest value ever recorded in the region.” In 2010, 36% of Waterloo's non-residential construction and 29% of residential construction took place within 800 metres of future rapid transit station areas.

“Without rapid transit, road expansion costs including property would be in the range of $1.4bn to $1.5bn,” says Mr Yung. “Achieving higher transit ridership targets will not eliminate the need for road improvements, but it can reduce the amount of road construction required and reduce road expansion costs by $400m to $500m.”

Cairo counts the costs

Cities around the world are beginning to see the wider costs of poor inner-city transport. Cambridge Systematics was recently asked by the World Bank to estimate the cost of congestion to Cairo’s economy. Mr Porter says: “Preliminary estimates of the costs of congestion in the greater Cairo metro area, which includes lost time, business productivity, air quality, carbon dioxide emissions, vehicle operating costs and safety [measured by the number of crashes], is in the range of $8bn to $10bn per year.” This compares with recent congestion cost projections of $5.2bn a year for Jakarta, $3.5bn for Sydney and between $8bn and $11bn for major US cities.

“These are hypothetical comparisons of current congestion versus conditions without any traffic congestion, which of course, is unachievable. But they do provide an order of magnitude of impacts,” says Mr Porter. “In cities with a high population and business density, you need transport that will move a lot of people efficiently, particularly in developing countries, and hence the need for mass transit, pedestrian access and limited car access.”

In the case of Cairo, even ambitious plans to build satellite towns and an underground metro system have done little to reduce the city’s notorious road congestion. Plans for up to three more underground railway lines have been discussed, but David Sims, a veteran city planner and author of Understanding Cairo: the Logic of a City Out of Control, is not optimistic. “It is anyone’s guess at what distant point in the far future these lines will materialise,” he says.

Mr Sims argues that with only 14.9% car ownership at the time of the last household survey in 2008 and rapidly increasing car ownership, Cairo’s transport problems can only get worse and now require more drastic action. “By midday, the entire city [grinds] to a halt under the sheer weight of traffic that builds as the day goes on.”

Satellite towns built in the desert surrounding Egypt’s capital were supposed to alleviate inner-city road congestion, but now even the roads connecting new towns with old Cairo have become choked with cars. By 2020, city planners had hoped that one-quarter of Cairo’s 20 million inhabitants would live in satellite cities, but with poor transport links, many satellite housing developments are struggling to increase their low levels of occupancy.

Bus alternative

Mass-transit rail systems may not be the answer for all large and growing cities, but there are cheaper yet effective alternatives. The Brazilian city of Curitiba’s development of a rapid-transit system based on buses running along dedicated lanes at high-frequency intervals with easy boarding has shown the effectiveness of bus alternatives to underground and inner-city rail.

In the 1970s, Curitiba’s city planners looked at the New York subway system and asked themselves if they could recreate something similar above ground in their own city, offering speed, reliability, comfort and high frequency. It started with 25,000 passengers a day travelling on one bus line each day and has grown to five dedicated bus routes, transporting some 2.3 million passengers each day. Now a staggering 75% of Curitiba’s population travel to work by bus, compared, for example, with Phoenix in the US (a similar-sized city) where just 1% of the city’s population travel to work by bus.

This idea has been copied across Latin America, and is spreading to cities in the Middle East and Asia. In Mexico, Guadalajara’s 16-kilometre rapid bus transit scheme opened in 2009 and carries 125,000 people each day. The scheme will be expanded to 81 kilometres during 2012. Similar but smaller systems have also been developed in Johannesburg and Cape Town in South Africa, with dedicated bicycle lanes running alongside the bus rapid transit corridor.

In the past 10 years, a string of Chinese cities have developed rapid bus transit system, including Guangzhou, Lanzhou, Huizhou, Wuhan, Harbin and Fuzhou. “Bus rapid transit is a way to move a lot of people efficiently without the same level of capital costs that goes into a subway or rail line,” says Mr Porter. “It is also more flexible than rail.”

Whether cities invest in high-end metro lines or lower-cost bus rapid-transit routes, unblocking clogged inner-cities is essential to unlock their economic potential.