Emergency services were called to Derby Road, near the Queen’s Medical Centre entrance, at 7.32 pm on Tuesday 6 February.
The victim, a 73-year-old man, remains in hospital with serious injuries.
Officers believe two vehicles were involved which have been identified and recovered. They are now appealing for additional witnesses to come forward.
Sergeant Craig Luckett, of Nottinghamshire Police’s road policing unit and serious collision investigation unit, said: “This incident happened on a busy road and will have been witnessed by other people.
“So if you saw what happened and have yet to get in contact with us, please do not assume that others have already told us what you saw.
“We are working to build up a complete picture of what happened and are particularly keen to review any dashcam or mobile phone footage recorded at the scene.
“We want to view any footage recorded either at the time of the incident, or after it had taken place.
“This can be sent directly to us and may prove to be vital to our investigation.
“Finally, I would also like to thank the members of the public who came to the injured man’s aid and stayed with him until emergency services arrived. This was a distressing incident for everyone involved and they acquitted themselves admirably in a difficult situation.”
• Police statement after pedestrian seriously injured near QMC
