The three-way junction is being built to serve the New Monks Farm development in Lancing, but planning conditions state a fourth, northbound exit must connect with Coombes Road.
Lancing College insisted on the amendment during the consultation process to ensure access for vehicles travelling east and west along the A27.
Developer The Community Stadium Ltd’s preferred option is a 330m lane that runs alongside the existing A27 carriageway before connecting to Coombes Road via The Drive.
The planned route would have the least impact on the South Downs and require removing the fewest trees, according to the developer, with almost no change to air and noise pollution.
The existing A27/Coombes Road junction would be removed, as would five trees and vegetation, albeit with replacement greenery and landscaping added.
The new lane would also have pedestrian and cycling paths alongside, with a 20mph speed limit for vehicles.
Traffic lights at the Sussex Pad will also be removed.
Comments on the application are overwhelmingly in favour – 31 letters of support compared to 12 against – but environmental group Adur Residents Environmental Action (AREA) has objected.
The group expressed concerns around noise and air pollution, particularly given the road’s proximity to the nursery in the former Sussex Pad hotel.
Pollution from traffic is expected to rise as a result of hundreds of new homes and the IKEA superstore, and AREA has warned the removal of vegetation could increase noise pollution.
Preparation work for the approved three-arm roundabout is already underway, with no date set for a decision on the fourth arm.
A spokesman for Highways England said much of the work would take place on the New Monks Farm and former Withy Patch travellers’ site, with little impact on the existing A27 carriageway.
For more information on the plans, search ref AWDM/1906/20 on the Adur and Worthing planning portal.
The New Monks Farm development, next to Shoreham Airport, will include 600 new homes as well as an IKEA superstore, community park and a school.
After a long, divisive planning process and delays brought on by the coronavirus pandemic, work is finally underway in earnest.
Read more about the development here: