There are several reasons for this reversal of fortunes for rail transport, which has seen a steady decline during the last 30 years through a mixture of political instability, civil war, economic decline, corruption and indifference. Many African countries now have relatively stable governments enabling them to start planning for the future.

This is also helping to encourage the world's mining giants to return to Africa to start exploiting its huge mineral wealth, which means investment in heavy-haul railways, as we reported in January. And, as in other parts of the world, African cities are starting to recognise that rail can play a valuable role in developing a transport network, something which is long overdue and sorely needed.

Speaking at the opening ceremony of the UITP Congress in Geneva in May, Mr Joan Clos, executive director of UN-Habitat, highlighted the acceleration in global urbanisation and how this is affecting Africa. He says that never in human history has the trend to urbanisation been faster. More than 50% of the global population now live in urban areas and this is expected to increase to between 65 and 70% during the next 30-40 years. To make matters worse, the world's population is expected to grow from 7 billion today to 9 billion in the future, provided there is no major change in economic growth. These twin trends represent a huge challenge to transport planners.

Clos says that with industrialisation it has taken 30 years to reach a situation where around half of China's population lives in urban areas. "We are now witnessing a very different urbanisation in Africa - it is growing at the same speed as in China but without industrialisation," says Clos. This means urbanisation without jobs, with the result that 65% of people in African cities are living in slums.

In a planned city, such as New York, about 36% of the land is allocated to streets, whereas in slums it is just 2.3%, and the average for sub-Saharan African cities is 10%. As Clos points out, it will take a huge effort to develop transport networks in these cities, but this is vital if they are to develop and prosper.

Far too many African countries have allowed their limited road and rail networks to fall into disrepair with the result that they are not largely fit for purpose, and have failed to keep pace with population growth.

Nigeria, for example, now has a population of around 170 million and 24 cities with populations exceeding 100,000. But Nigeria's rail network still reflects its colonial past and has only recently started to receive some long-overdue attention. As we report this month, the country is now starting to build new lines and has ambitious plans to create a proper network in the south of the country to connect many of its large cities by rail for the first time.

Similarly, construction is underway of the first metro line in Nigeria's largest city, Lagos, which has a population of 20 million and appalling road congestion due to an inadequate public transport network.

The metro is being implemented as a PPP, with funding for the infrastructure being provided by Lagos state government and bond sales, while the private sector will pick up the tab for the moveable assets as well as operations and maintenance. As passenger demand is expected to be high, the private sector was confident enough to offer bids for the 25-year operating and maintenance concession which included payments to the government.

To keep costs down, the concessionaire has purchased a fleet of 35-year-old trains from Toronto which are expected to last the life of the concession, with refurbishment half way through. This could be a model for other African cities to adopt which would make investment in rail projects much more manageable.

The use of second-hand rolling stock is not new. Spanish trains are a common feature on South American railways, for example, while old German trams are running on new light rail lines in Eastern Europe and Turkey. But railways and urban operators have been slow to exploit this potential, and need to consider trying to find new homes for their old rolling stock.

As SCI Verkehr's report on Africa demonstrates, the continent is becoming one of the world's most dynamic railway markets. More than $US 50bn is expected to be invested during the next 10 years in the construction of 4000km of heavy-haul railways to extract minerals, while the market for railway technology and services is expected to grow by 10.2% a year to reach €5.4bn in 2017. But don't wait to get a slice of this lucrative market, because the Chinese, which are already well-entrenched in several African countries, have a head start.