We all know that blue and red flashing lights mean cops, ambulance and fire use mostly red lights, and amber and red mean snow plow ahead. But what does a flashing green light on a vehicle indicate?

You might not be aware those green lights indicate a volunteer firefighter heading to a call. Lacombe County Fire Chief Drayton Bussiere says they call it a courtesy light, and volunteers get them once they become full volunteers with their department.

"It's kind of our way of having our volunteer firefighters kind of ask the person in front of them to move over and let them go by. So we have some bylaws that allow our guys to use those. It's really just a, 'hey I'm on my way to the fire hall, could you do me a favour and move over so I could potentially get there a little faster.'" 

Bussiere says unlike police or fire vehicles, these lights do not give the volunteer firefighters the right to circumvent traffic laws.

However, Bussiere says since it is a courtesy, you're under no obligation to give them room, besides being polite.

"These lights are a courtesy light, so if people are confused and don't move out of the way we understand that, and we also expect very highly, that our members will drive responsibly while using them. If people do see these lights and they see somebody driving irresponsibly with the light we do want to know about it."

They can also display a yellow license plate on the front of their vehicle indicating they are volunteer firefighters.