Andrew Marr rickshaw cycling in the Dhaka rush hour

There are more than 600,000 cycle rickshaws on the streets of Dhaka, many driven by young men who have come to the city looking for work.

With no tube system and only two railway lines serving the Bangladeshi capital's 13 million population, the rickshaw is a popular way for people to get around, particularly during the rush hour which seems to last most of the day.

Andrew Marr's Megacities looks at how people live in five of the world's biggest cities - London, Dhaka, Tokyo, Mexico City and Shanghai. The final programme Sustaining the City can be seen on BBC One at 2000 BST on Thursday 16 June 2011 and afterwards onBBC iPlayer(UK only).