Cheshire East Council has agreed to fund full planning for the scheme, including the development of a business case.
The preferred option is to widen the road on land to the south rather than the north, increasing traffic capacity to accommodate housing growth and paving the way for HS2 construction traffic.
Widening to the south is the preferred option of three widening schemes considered as part of consultations that have taken place with stakeholders, including landowners, tenants, parish councils and Highways England.
Councillor David Brown, Cheshire East Council cabinet member for highways and infrastructure, said: “This is a scheme we need to press ahead with as we expect to see the arrival of construction traffic for the proposed HS2 hub station by 2021. This is a key infrastructure project that is essential to support Local Plan-led housing and employment growth around Crewe.”