l am in a tiny steel cage attached to a motor cycle, stuttering & through traffic in Dhaka. In the last ten minutes we have moved forward may be three feet, inch by inch. Up ahead, the traffic is jammed so close together that pedestrians are climbing over pickup trucks and through empty rickshaws to cross the street. Two rows to my left is an ambulance, blue lights spinning uselessly. This is what the streets here look like from seven O’clock in the morning until ten O'clock at night. If you are rich, you experience it from the back seat of a car. If you are poor, you are in a rickshaw, breathing in the exhaust. I am sitting in the back of a CNG, a three wheeled motor cycle shaped like a slice of pie and covered with scrap metal. I am here working on a human .Tights project, but whenever I ask people in Dhaka what they think international organizations ‘should really be working on, they tell me about the traffic. Alleviating traffic Congestion is one of the major development challenges of ‘our time. Half the world’s population already lives in cities, and the United Nation estimates that the proportion will rise ‘to 70% by 2050. Dhaka, the world’s densest and fastest growing city, is a case study in how this problem got so bad and why it’s so difficult to solve.