The funding, provided by Homes England and the Department for Transport, will go towards Oxfordshire County Council’s A40 improvement programme.
The programme will focus on making bus travel better and walking and cycling safer for the thousands of people who use the route.
The council’s proposed scheme includes the construction of a new junction that will link to the new park and ride at Eynsham, making it operational.
This will provide additional travel options and make journeys safer and faster for both residents and visitors to Oxford, the council said.
Councillor Judy Roberts, Oxfordshire County Council’s cabinet member for infrastructure and development strategy, said: “We are happy to have received the support of Homes England and the Department for Transport for our plan.
“This investment is a crucial step towards improving the overall travel experience along the A40 in West Oxfordshire.
“We are prioritising improvements to bus travel here, as well as walking and cycling infrastructure to help create a more sustainable, healthier, and connected county.
“This project could really bring a step change in travel for those who live in, work in, and visit West Oxfordshire and for people using the A40 between Witney, Eynsham, and Oxford.”
The project aligns with the council’s vision for a greener, healthier, and more accessible county, it added.
Along with the park and ride site at Eynsham, the planned bus lanes and active travel facilities are expected to support the provision of new homes in the West Oxfordshire area.
The current scheme designs come after a review of the A40 improvements programme due to continued high inflation and construction cost increases since 2020.
The council said it has worked with the government to secure the existing level of funding, adapting the programme’s design and phasing its delivery to provide upgrades to travel in the area.
It said future planned phases of work can be provided when further funding has been sourced.
The funding secured for the scheme comes from the Department for Transport’s retained Local Growth Fund and Homes England’s Housing Infrastructure Fund.
With approval now in place, the county council is set to apply for planning permission.
It will also be planning a number of engagement opportunities for the public to review the plans in detail from November.
Subject to planning permission, construction could start in early 2026 and last for two years.