The preferred route of a northern bypass road in Norwich needs more consideration, officers have said.
The environmental and traffic effects of the Northern Distributor route between the A1067 and A47 needs further research, a report to the cabinet said.
Director of transportation Sam Ralph requested the deferral on Wednesday.
The results of the consultation are expected to be discussed by Norwich county and city councillors before the cabinet meets on 7 March.
Support for road
Mr Ralph said: "We have always recognised that the environmental impacts of a new route in this area would be significant.
"Following our detailed environmental assessments, and the responses from the statutory environmental bodies, we believe that a new river crossing could be difficult to achieve," he added.
The need for a Norwich Northern Distributor road has been included as a regional priority in the draft East of England Plan.
About 78% of local residents have supported the relief road in principle, according to consultations by Norfolk County Council.