Cow closes Melbourne tunnel

CityLink was forced to close a lane in the Domain Tunnel in Melbourne this morning after a cow on a livestock truck smashed into an electronic road sign.

CCTV captured the moment a cow on the top level of the truck reared up and crashed into the sign about 10.25am, before the truck continued to drive out of the tunnel.

CityLink spokeswoman Selby-Lynn Nicholas said it was unclear whether the truck driver knew about the collision, or whether the cow had survived the accident.

It was the second serious collision involving cows on Melbourne's roads today, after an ambulance crashed into and killed a cow at Badger Creek north-east of Melbourne.

Ms Nicholas said CityLink crews closed the Domain Tunnel's centre lane to assess the damage to the sign, while two other lanes were reduced to 40km/h.

The sign was temporarily secured until repairs are carried out tonight, and the lane reopened 20 minutes later.

"We don't know what the condition of the cow is because the truck continued through the tunnel," Ms Nicholas said.

"It's really bad footage, it shows the cow reared up a little and then went back down."

She said it was unclear whether the sign - used to advise motorists of lane closures - hit the cow on the head or back.

"Basically from what I'm told these trucks basically sort of just go underneath the height restrictions in the tunnel so obviously it's big enough that if a cow just pops its head up it can hit [a sign]," she said.

Ms Nicholas said CityLink had an informal agreement with the Australian Livestock Transporters Association for trucks to bypass tunnels when they had livestock on board.

"So I'm not quite sure why in this case that hasn't happened," she said.

Earlier this morning, a cow was killed when an ambulance responding to an emergency rounded a bend and hit the animal on Wallaby Way at Badger Creek.

Ambulance Victoria spokeswoman Lauren Nowak said the paramedics were not injured in the collision at 2am, but the ambulance was significantly damaged and had to be towed away.

She said another paramedic crew was sent to treat the initial patient, whose condition was not life-threatening.