Hybrid HOV Access: Feds doing what states have already done?

Hybrids and HOVs: Do the Feds really need to get involved?

The EPA is reviewing its certification of clean and energy efficient vehicles to help states determine which hybrid vehicles should be allowed in HOV lanes. While I don't know every state's legislation, California, for example, is already more strict than the EPA. Maybe the Feds should just leave things alone?

(Source: CNN)