The new Merafield Bridge will be 80 metres long, 11.3 metres wide and made of 2,503 tonnes of concrete and 401 tonnes of steel.
It will be developed alongside the old bridge this autumn.
Once the new structure is opened to traffic, the old bridge will be demolished.
Work is scheduled to begin on 9 September and continue until the summer of 2016.
Highways England's Julian Strong said: "This is a big project. We have carried out extensive planning and worked very closely with our stakeholders, including Plymouth City Council, the Plymouth and Devon Chamber of Commerce and local businesses.
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"We know there may be some concerns about the impact on traffic, but we will work hard to keep disruption to a minimum and will install the new bridge as quickly as we can.
"The good news is that the extensive design work means we will keep three narrow lanes open in both directions for most of the time and access to Merafield Road will be largely unaffected."
Construction work will normally be carried out during the day.
Occasional overnight work will be necessary when the new bridge sections are lifted into place.
Impact from those working on the construction site will be minimised by staggering deliveries and creating an unloading area within the site compound.
(LM)
