The carriageways reopened at 1:30 am on Saturday 12 February.
The A46 between Wanlip and Wymeswold reopened after being closed since 2:30 am on Friday 11 February.
A murder investigation has been launched following a road traffic collision on the A46 near to the Six Hills junction at about 1.35am on Friday 11 February.
Two people were pronounced dead at the scene.
The investigation is in the very early stages and work is being carried out to ascertain the circumstances of the collision and what happened in the minutes before.
Detectives want to hear from anyone who saw three cars travelling in the area of Troon Way or Abbey Lane at around 1.25am, and on the A46 between the Thurmaston Shopping Centre and the Hobby Horse Island.
The cars – a silver Skoda Fabia, a grey Audi TT and a blue Seat Leon – were travelling at speed and work is being carried out to work out the routes taken.
Detective Chief Inspector Tony Yarwood from East Midlands Special Operations Unit said: “Anyone who was travelling in the area in the early hours and has any dashcam footage, we are urging you to come forward.
“We are working to piece together the movements of all the cars involved and any footage of them will help our investigation.”
A post-mortem examination has not yet taken place.
Four people have been arrested on suspicion of murder. Two women aged 45 and 22, and a 20-year-old man from Stoke, and a 21-year-old woman from Birmingham are all in police custody.
Anyone with information can submit it online on the Holmes public portal or can alternatively call Leicestershire Police on 101 quoting incident 30 of 11 February.