The woman, who was driving a black Honda, collided with a white VW van which was turning out of the post office, just in front of Howard Street in Epsom on Monday, April 15.

Police believe that around 9.10am the van driver, a 61-year-old Neilborough man, was turning out of the post office to head south along the highway.

A number of lanes of traffic began to give way to the van before it and the black Honda collided.

The van driver received minor injuries while the pregnant Honda driver was taken to hospital for observation but was otherwise appeared uninjured.

Traffic was slowed for around an hour after the crash with police, CFA and Ambulance Victoria on scene.

Victoria Police Sergeant Mick McCrann said he wanted to thank the witnesses who were able to give their account of the events to police.

"Thankfully we had a number of witnesses on scene able to detail what had occurred and we appreciate them sticking around," he said.

"The road safety message is pretty simple, if you are going to enter a lane of traffic make sure it is clear to go."