I've often wondered if allowing hybrids into the HOV lane is more a reward for those early green-goers who've chosen hybrids based on their own personal calculus, or is it more of an encouragement for those hybrid teeterers looking for a little more in-it-for-me. It's good highway management, especially on roads where the HOV lanes go under-utilized. Either way, it's great policy (if only until the HOV lanes get clogged with 1-passenger hybrids).