The weekend closures will allow for work to complete the dualled A47 between Norwich and Dereham.
Norfolk Police has reopened the A47 after an earlier collision involving several vehicles.
The road has been closed for an investigation to take place, says National Highways.
The mayor says the move will prevent him from looking at other funding methods.
National Highways says bad weather meant asphalt-laying work had to be delayed.
Norwich City Council says the market will still be moved and it has another "preferred site".
Norfolk Police says it is appealing for any witnesses or anyone with dashcam footage.
Summer Mace says the speeding driver who killed three of her relatives should have stayed in prison.
Alistair Stout urges road users to "bear with us" during long delays and disruption at the junction.
