If you're not driving any faster then prevailing traffic, even though you're car pooling, STAY TO THE RIGHT! Pisses me the fuck off.
Me and the wife are fortunate enough to be able to commute together and use carpool lane for most of our 30 mile drive each way every day. Kind of a challenge for me, but nerve racking for the wife, trying to get around 62 MPH driving dicks in the Carpool lane.