It's all about taming traffic: keeping a tab on the number of vehicles on the road, and promoting public transport. Singapore, one of the smallest but richest Asian cities, has mastered this art. From being one of the most polluted Asian cities three decades ago, its pollution levels are now below World Health Organisation standards. They have remained so for 10 years now. Its citizens breathe air, which is among the cleanest in the world, while people in its South Asian counterpart, India, are choking in exhaust fumes. Indian policymakers need to take a close look at the Singapore model that guarantees its rich citizens the right to clean air. But for this, they have to take the bus, cycle or walk