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Once known as East Africa's green "City in the Sun", Nairobi is so choked with traffic that Kenya's architects suggest moving to a new capital and angry business leaders say the booming economy is under threat.
Bad drivers, ramshackle vehicles, overloaded trucks, pot-holed roads and corrupt traffic police make one of Africa's biggest cities resemble dodgems on a good day and, when things get really bad, reduce it to gridlock.
Swarming minibuses, known as matatus, are the only option for most Nairobi commuters but are notorious for their drivers' kamikaze tactics and their crumbling mechanical condition - which often means no lights at night. Matatus, weaving wildly from lane to lane, account for 80 per cent of public transport and are a major cause of congestion. Fatal crashes are common.
Kenya's crumbling roads and the chaotic traffic have become a political issue ahead of elections in December, denting the popularity of President Mwai Kibaki.
A recent survey said traffic jams were costing Nairobi drivers up to 50 million shillings ($1 million) a day through increased fuel consumption, mechanical damage and pollution.
"The amount of fuel used is astronomical, just sitting in traffic idling away," said Betty Maina, head of the Kenya Association of Manufacturers.
She said the turnaround time for trucks and vans had doubled and some companies were increasing the sizes of their delivery vehicles because of the delays, compounding the problem.
The Architectural Association of Kenya last month asked the Government to move the capital elsewhere.
"Nairobi was designed half a century ago for a population of half a million people while the population today is three million. This has overstretched entirely all the services of the whole city," AAK chairman Gideon Mulyungi said.
City traffic is worst on Friday evenings, especially near pay day. When rain turns the potholes into ponds, there is chaos. Some estimates say traffic has expanded by 300 per cent in a decade.
Plans to overcome Nairobi's congestion - bypasses, overpasses and 14 "missing links" to avoid long detours - began 30 years ago. Nothing was done.
The reason, say experts, was systematic corruption during the 24-year rule of former President Daniel arap Moi, who was replaced in 2002.
Big donor countries privately express frustration that a comprehensive 2006 Japanese plan for solving Nairobi's road and traffic problems has still not been implemented.
Roads Ministry spokesman Richard Abura said it had taken time to find donors to fund the work. In April, Kibaki announced plans for a Chinese project to widen the main highway and link it to the west of the city.
But some Western donors complain this is not co-ordinated with the Japanese plan and many people remain sceptical at the pace of change.
- Reuters