Haven't been here long enough (~12 months) to anecdata that, but it's generally recognized that government policies are increasing air quality rapidly in many major cities. Example policies: routinely spraying water on the roads in dusty areas and near construction sites, banning motorbikes from city centers, banning the import of second hand vehicles, encouraging electric vehicles, moving polluting industries away from population centers, increasing industrial regulation, reducing opportunities and increasing penalties for corruption. I have a German friend who builds air quality monitoring systems for export here and he said that restaurant kitchen air vents are actually one of the worst urban air polluters now. Another is construction. He said India's cities, especially Delhi, are literally off the charts (sensors incapable of registering pollution levels that high) and that, compared to India, China has things well under control.
Dirty thing people miss about motorbikes. Better mileage, but not as much as you would think, in return for a lot more emissions. That said I'm lead to understand that electric motorcycles and bicycles have become very common in China.
Larger motorcycles, like Harley Davidson, use the same size engines as compact cars, like the Honda Fit. And they make a lot more noise dong so, which is part of the marketing for them.
Will automakers start putting "engine speakers" on electric Harley Davidson motorcycles and playing engine noises through them?
