More than 1,000 homes could be built on the outskirts of Bury St Edmunds under outline plans submitted to West Suffolk Council.
A new primary school and a 'village' centre of shops and other services would also be built to serve up to 1,375 proposed homes in Great Barton.
However the proposals, currently open to public consultation, have sparked fears the existing road network will be unable to cope with the extra traffic generated.
The huge new estate by developers St Joseph Homes Ltd, part of the Berkeley group, is proposed for just over 78 hectares of agricultural land 500 metres south of the existing village of Great Barton.
Access would be via two new roundabouts - one on the A143 Bury Road on the northern side, and the other 300 metres from the existing junction with the A143 and Orttewell Road in the south.
The new estate would feature parks and community gardens, play areas, allotments and urban farms. It would also see the creation of new foot and cycle links into the site, crossings of the A143 and a link through the existing railway underpass.
The council is being asked to approve a full application for 291 homes as part of the first phase of the scheme.
The land has been zoned for development since 2013 when the Vision 2031 growth plan for Bury St Edmunds was adopted by the former St Edmundsbury District Council, and then by its successor West Suffolk on its formation last year.
Ward councillor Beccy Hopfensperger said the application was no surprise and new homes were needed in Bury St Edmunds but it was important a balance was struck.
"There are strong local concerns about the pressure this much new housing will put on the current road infrastructure," she said.
"It's already very busy and then there is the added pressure being brought by the new West Suffolk waste and recycling hub.
"We need to be able to come to a sensible approach that will see a development providing much needed housing but also addressing the local issues."
Ms Hopfensperger said it was important a green buffer was kept between the village and Bury St Edmunds but development had to take place: "It is a vast number of proposed homes and it will have a huge impact, but we need affordable housing that lets local people stay in their communities."
The public consultation concludes on February 13. The proposals are not expected to be considered by planning members before spring.
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