It happened at the junction of Ashby Road and Regent Street shortly before 10am yesterday (10th May) and involved a Renault lorry and a mobility scooter.
Police are appealing for anyone with dashcam footage to come forward.
The person in the mobility scooter – a man in his 30s – was taken to the Queen’s Medical Centre in Nottingham. He remains in hospital where he is being treated for life-changing injuries.
No-one has been arrested in connection with the incident.
Detective Constable Kasie Carter, from the Serious Collision Investigation Unit (SCIU) is the investigating officer. She said: “I would like to speak to anyone who has information regarding this collision but has not yet contacted police.
“I’m particularly keen to speak to any motorists who were in the area at the time and who have a dashcam in their vehicle.
“I am also interested in speaking to anyone who saw either the lorry or the person in the mobility scooter prior to the collision occurring. Any information you have could help.”
The crash left the road closed for several hours and traffic was severely disrupted.