Heighington Road and its new 33-metre long bridge above the bypass opened to traffic on Friday 31 January.
Cllr Richard Davies, executive member for highways, said: "The new Heighington Road bridge is officially open for people to use. And as part of that, Heighington Road itself is now re-open.
"Getting the new bridge built was a massive undertaking since it involved splitting Heighington Road in half, digging out 16 metres of rock and earth to make space for the bypass and then reconnecting the road with a new 33-metre long bridge.
"We want to thank everyone for their patience over the past fourteen months while this huge structure was being built."
A further closure of Heighington Road will be required later this year to remove the concrete plant crossing currently in place and resurface that section of road. This won't take place until the closure at Washingborough Road has ended.
In addition, works to complete painting the bridge will take place later in the year under temporary traffic signals during warmer temperatures.
Cllr Davies continued: "With Heighington Road now re-opened, the team will make a start building the roundabout at Washingborough Road starting in mid-February.
"As part of this, Washingborough Road will be closed for up to five months. This will allow Galliford Try to lower the road by about 1.5m before carrying out drainage, street lighting, kerbing and surfacing works.
"We'll be doing everything we can to minimise disruption, including doing our very best to get Washingborough Road opened sooner than planned. However, that will be dependent on what the weather is like."
The diversion route for non-HGV vehicles will be via Church Hill / Canwick Road / Sheep Wash Lane / Branston Road / Station Road / B1188 Lincoln Road, and vice versa.
The diversion route for HGVs will be via B1188/Lincoln Road to B1202 to B1190, and vice versa.
The 7.5km Lincoln Eastern Bypass project is part-funded by a £50m Central Government capital grant and will improve Lincoln’s infrastructure, encourage growth, minimise traffic congestion and enhance the inter-city environment.
For the latest news on the Lincoln Eastern Bypass, visit www.lincolnshire.gov.uk/leb.