I think these people have not visited India in recent years or they are biased to other country. Matter of the fact is India has officially faster capacity on road basis. In US maximum official speed is 70 MPH (~115 kmph) including all type of roads.
The developement of the Bangalore airport to city road limit is going to be 180 kmph and it will finish by 2010. This will be real achievement by India. Right now, Express Roads are having 110-120 kmph. All of these are official. Unoffcially people do drive 130-140 kmph on Express roads.
I do believe on Highway Police and catching of violation of the speed limit are liberal in India and its really very well implemented in US. These do increment Average speed but not the Fastest speed.
We are no longer behind ....