An initial investigation indicates that the Cadillac SRX was traveling at a high rate of speed southbound in the carpool lane when the driver lost control, veered across all lanes and struck the sound wall along the on-ramp, said officer Denise Quesada of the CHP.
So look at the INTENTION of what the report is trying to say. It is trying to convey the message that the vehicle was traveling VERY FAST, i.e. "high speed". So instead of saying what it should say, i.e. high speed, it got cute by writing "rate of speed", which in this case, since the vehicle is moving linearly, means ACCELERATION!
They'll never learn!
But what was funny is that one of the comments listed with this story was someone pointing to my blog entry on this bad usage! :)