The raised slip road off the M56 westbound at Junction 7 has been restricted to one lane since 2006 because the bridge can no longer carry two lanes of traffic.
The slip road connects the M56 to the A556 which itself links drivers to the M6 at Junction 19.
The Highways Agency is spending £1.5m to resurface the carriageway and introduce a monitoring programme to assess the condition of the bridge and help engineers consider long-term options for the junction.
Highways Agency project manager Phil Hardy-Bishop said, "This work has been part of our continuing commitment to keeping this vital junction open and ensuring that a long-term solution to the bridge's problems is identified.
“We have aimed as always, to keep disruption to drivers to a minimum but I would like to thank drivers for their patience over the last few months while this work has been going on.”