This seems washed out in color to me - and nothing is sharp. Plus the car and bus compete for my attention. I would prefer to see a car or the bus sharp against a motion blurred background.
I know that the title is speed, and I can see what effect you were going for (I think), but with the entire image out of focus the effect is lost and it's just a blurry. Would have been much better had there been motion blur, but only for the background with the main subject(s) in focus.
I like the idea and the smoggy feeling of this photo. A little improvement would be - according to my mind - to make this pic more panoramic. I would crop 1/3 from down. This photo would have been a bit clearer, too, if the passenger car and the bus would have been separate to each other.