In 2019, National Highways, previously known as Highways England, put forward six colour-labelled options for the A27 bypass that the public could have their say on.
Andrew Jackson, National Highways senior project manager, said the team has been continuing to work closely with landowners, local people and businesses to 'develop our plans for the A27 bypass'.
He added: "We want to make sure we can present to the public an appropriate proposal for consideration.
“However, this is a very complex project and a short delay until January next year is necessary so that we can better present all our findings, and explain how the scheme will be safe, affordable, environmentally-led and meets its aim of reducing congestion.”
Campaigners against the road have argued that the multi-million pound project would be 'environmentally damaging'.
Arundel Bypass Local Campaign Groups questioned if the delay was to avoid highlighting the plans at the same time as COP26 climate summit — an international conference on the climate, currently hosted by the UK in Glasgow.
"Public awareness of the destruction of our climate and nature caused by new roads and increased traffic is heightened by COP26," said Arundel-area resident, Camilla Lambert.
"We think National Highways doesn’t want it reported that what they are planning is totally at odds with the zero carbon future that we must meet.
"It makes the UK look hypocritical as it leads the conference. In this climate emergency the government should be spending this money on alternatives to driving instead of such a damaging road scheme."
The 8km dual carriageway is one of a set of road projects in the £27 billion Road Investment Strategy (RIS) for England, planned by National Highways.
Kay Wagland, who chairs the Arundel residents’ campaign group, said: "It looks like National Highways can see the writing on the wall and that people are realising that we just can’t keep building more big roads and expect to meet urgent climate and biodiversity targets.
"They are undertaking as much preparation work on the Arundel plans as they can now. This extends to commissioning a construction company before they have even started the statutory consultation process for planning permission."
The campaigners argued that the route selected for the scheme was an unpopular choice in earlier consultation and will 'devastate an area of exceptional wildlife, landscape and heritage'. as well as the three villages of Tortington, Binsted and Walberton, alongside the South Downs National Park.
A group spokesperson added: "Several local residents’ campaign groups and environmental groups are joining forces to oppose the National Highways plans for the A27 at Arundel.
"They have achieved a lot of support both locally and regionally for a lower carbon, lower cost, effective solution called the Arundel Alternative."