The consultation process will begin on 14 June and run until 27 July, with a focus on the airport’s revised highway design.
It will seek views on an updated North Terminal junction plan and a third lane to the A23 approaching Longbridge roundabout, as well as a new lane westbound over the Brighton main rail line.
Plans for a roundabout at the airport’s South Terminal will remain almost the same.
Gatwick plans to use the Northern Runway for departing aircraft by moving its centre line further north by 12m to facilitate dual runway operations with its Main Runway.
Gatwick Airport CEO Stewart Wingate said: “When we launched our initial public consultation last September, we wanted to hear from people and interested groups on our plans to bring our existing Northern Runway into regular use alongside our Main Runway.
“Following feedback on our proposals, we have listened and taken the decision to amend several aspects of these plans, particularly our highways designs, so we are keen to get further feedback from local people and other stakeholders on these updated changes before we take our plans forward.”
The Northern Runway is expected to start operations by mid-2029.
Most of the airfield construction works will be contained within the current airport boundary and require a £500m ($631m) investment, which will be privately funded.
Gatwick’s proposal is expected to create nearly 18,400 jobs by 2038, as well as contribute an additional £1.5bn in gross value added (GVA) to the region.
To help the airport meet its zero emissions goal by 2040, the project will be carried out in a sustainable manner.