On Thursday, a human skull was found alongside the M54 slip road by workers doing a survey of the junction four roundabout, near Telford.
Police confirmed the skull was that of an adult male and had been there for at least two years.
West Mercia Police said "further skeletal remains" were found close to the skull.
The eastbound entry slip road remains partially closed.
Det Chief Insp Neil Jamieson said: "We are in the very early stages of this investigation and inquiries are ongoing."
He said further forensic examinations and excavations were being carried out and police had been in contact with neighbouring forces asking for information about people who had been reported missing.
Archaeological experts may be called in to help with the investigation.
"This will be a lengthy process but we will continue to update the public in due course," he added.
More human remains have been found near a motorway slip road in Shropshire, police have said.