Fatma rides on the shoulder of the road, her infant daughter secured to her back with a length of brightly coloured kanga fabric.

Arms outstretched, she grasps the handles that function as pedals and rotates the chain around a gear, propelling herself through Dar es Salaam's heavy traffic.

On roads that claim upwards of 10,000 lives every year, people who cannot walk take on the traffic in hand-pedaled tricycles.

"If I don't use my bike, it would be very hard for my family to survive," she says.

The roads are not just dangerous for those with disabilities. With five million inhabitants, Tanzania's commercial and administrative capital is growing beyond the capacity of its infrastructure.

Trucks, buses and private vehicles share the road with mini-buses known as daladalas, which are sometimes so crammed that passengers have to disembark through rear windows.

Battered motorcycles and autorickshaws negotiate the space between cars, speeding along sidewalks and darting into opposing traffic to gain a few extra metres. Vendors form a slow procession between the cars, selling everything from fire extinguishers to cowboy hats and self-help books.

"Most people spend up to 43 days a year stuck in their car," says Mejah Mbuya, the founder of UWABA, Dar es Salaam's cycling advocacy group. "I'm talking about people who are spending two hours to go to work and two hours to go back home."

On these gridlocked streets, cyclists are trying to lay claim to a piece of the road.

During the annual Cycle Caravan, more than 400 people took to the streets to advocate for cyclists' rights and to encourage policymakers to recognise that bike lanes help make cities more livable and also save lives.

Mbuya has been organising the event since 2006, and is passionate about the benefits of cycling not only for the health of individuals, but also for the health of cities.

It is not only drivers who need to be mindful of cyclists, but also city planners and highway engineers, he says.

"They have to plan including people and people who cycle - not only for cars and buildings."

The city's planned solution to the jams is a new infrastructure scheme called the Dar Rapid Transit Project. Scheduled for completion in 2015, the project will rehabilitate 21 kilometres (13 miles) of trunk road to introduce a speedy bus system.

- Coping with mega-city status -

"We are working very hard to keep up with the pace, to design an intensive master plan with Dar es Salaam," says Jerry William Silaa, the mayor of Illala Municipal Council, which includes the city centre.

Sporting a helmet and reflector vest at the Cycle Caravan, he says the plans also include dedicated bike lanes.

"We are trying to make the city live another 100 years to come because with this growth we are going to reach a population of 15 million people and go to mega-city criteria by the year 2025."

Dar es Salaam, along with other rapidly urbanising cities in east Africa, must follow the smart cities model and become more sustainable and innovative, the mayor says.

Other government responses to urban sprawl have included a recent ban on semi-formal modes of public transportation, like motorcycles and autorickshaws, in the town centre. But this has failed to alleviate congestion in the busy area.

"The thing with infrastructure is that it's a socio-technical system, and so you might improve the technical aspect of it, but then the social and economic side might undo all the good work that you've done," says economist Angela Ambroz, a researcher on urbanisation.

"So the example with widening a street, if you widen a street to address traffic, all that's going to happen is that your supply increases, but then your demand will increase to meet that supply, and you'll have congestion again down the line."

One way in which citizens are addressing congestion is by developing their own strategies for negotiating and thriving in a growing city.

Filbert Mbecha works as a dispatcher and messenger at FASTA, the city's first bike courier service. While the idea is still novel to many people, the business has attracted diverse customers since they hit the road three years ago, delivering everything from letters to wedding cakes.

"As a courier, I'm very relaxed when I'm riding a bicycle, when the car is stopped in a traffic jam - for me I'm going very fast," says Mbecha.

He says he hopes that Dar es Salaam's infrastructure will soon accommodate cyclists. And with the crowded city expected to triple in size over the next decade, he is not alone.