A second factor promoting better air quality is the requirement for a periodic certificate of pollution compliance. I understand that testing is every six months for private cars. Tis certainly helps keep the older polluting cars off the roads. I have yet to see any spot checks by police of pollution compliance documents, but friends say that it does happen.
The ban on smoking in public also seems to be effective. I see very few people smoking in lanes or on streets or around college campuses.
Another hopeful sign is that the garbage crisis that was only too visible when I left last year appears to have been somehow resolved. I returned to my old neighborhood (near Mhatre Bridge) and the piles of garbage are gone. Friends tell me that a new collection system is in place and it wi working.
Does this mean that the city is becoming more governable and that the elected officials are producing results? I think that it is too soon to declare a trend.
On the negative side of the ledger, traffic is worse. Even though large trucks are banned, it is not unusual to be stuck in traffic for 10-15 at much used intersections. I have seen no new traffic lights or other forms of traffic control installed in the year I was away. There seems to be slow progress on a couple of flyovers, but I did not see any new ones actually open. The Mumbai-Pune road as a divided highway still stops 15 kms From the center of the city. (At the Mumbai end, however, I have been told that a new expressway takes traffic to the airport and another brings traffic right down to the Fort area.)
So, for now, the sustainability picture seems mixed, with some real progress on air pollution tempered by more cars, more sprawl, and the continuing of diesel rickshaws and busses.