"Emergency Vehicles" in HOV

Does anyone know what the definition of an emergency vehicle is for the purpose of the HOV[?]

I recently sent a comment to VA State Police about the inordinate number of SOV in the lanes. They said that "emergency vehicles" are permitted. My issue is, why is a DC or MD unmarked police car or apparently anyone who puts a blue flashing light on their dash allowed to use HOV for their daily commutes?

There are a ton of cops who commute in their work vehicles in order to use HOV lanes.

It is a violation, it is wrong. If you are a slug, write down their tags and call the appropriate jusrisdiction.

smithma,

I don't know the answer to your question.
It seems like a clarification on emergency and law enforcement vehicle HOV use is something that should be asked of VDOT who publishes the rules, or of the State Police who enforce them.

As I read it, I think exemption #4 says that public utility vehicles (power, water, and gas company vehicles) are exempt from the HOV restrictions only when they are responding to emergency calls. The exemption appears to treat them differently (exempts them only when they are responding to emergency calls) than the fire, ambulance, rescue, and law enforcement vehicles mentioned in the first sentence of the same exemption. Exemption #4 does not appear to place a restriction on when fire, ambulance, rescue, and law enforcement vehicles can use the HOV lanes.