I was born in Los Angeles, a city with miserable amounts of traffic. Every rush hour, the entire city comes to a standstill, because there are too many cars on the road and they are in each other's way. The slightest slowdown anywhere in the traffic grid makes slow-moving, congested, stop and go traffic lines that go on for miles and miles. A traffic engineer once told me that traffic jams like that start when there is over a critical threshhold of cars, and one of them goes slower than 35MPH on the highway. (That would be 20 - 30 MPH under the limit, a significant slowdown.) Often, this is an accident, reducing at least two cars to 0 MPH and other cars around it to speeds under 20MPH as they slow or stop to gawk.
Most of China's cities are even denser than Los Angeles, and can suffer traffic jams that are longer than the city itself. So there's a big effort to push some of this traffic to busses, trains, and subways. And now on top of that, busses just got a big improvement. Busses may just be one very large car, but it's one very large car that takes so many people around that 30 or 40 other people aren't driving a private car. So it reduces traffic slightly. The new busses from China are raised above the street with a hollow first floor that cars can drive right through. Busses and their perpetual stopping are no longer a source of traffic jams. If the bus isn't going fast enough for you, you can drive right under it. If the bus stops to pick up passengers, you'll go right under it and no one on the bus will notice. The people are still transferred about...but as far as the cars below are concerned, it's like it's not even there.
I'm now thinking, what else can we do to alleviate the traffic problem? Near Los Angeles there's a really great light rail system, but it stops short of the city where'd be useful. Why? Taxi lobby bitched and the city caved. It would be helpful if that would be extended, perhaps into a subway system? And speaking of subways, if we build a tunnel highway beneath existing ones, we'd have twice the capacity in the same space.
But to really solve the problem, we'll need some sort of transportation that's completely different altogether.