The preferred route would then be announced in September 2015 and the plan would be to start construction in February 2018 with a completion date of December 2019.

[7] After five options were published and two dropped the government cancelled the whole project on 28 February 2017, citing lack of support from local authorities as the main reason.

[11] A proposed scheme to bypass Arundel was dropped in 2003, although the junction at the end of the dual carriageway has been partly made into an underpass.

[12][13] However, the scheme was relaunched in Spring 2018 when Highways England announced their preferred route, choosing a "a modified version of Option 5A".

[14] Although the document claims 48% of respondents support this option, there are worries that the new road may damage ancient woodland in the South Downs National Park.

[16][17] At Worthing, where the possibility of a bypass has often been discussed since 1967, even getting as far as passing the inspector's report at a public inquiry, the plan was dropped in 1996 following rising costs.

[24] Further, it is widely considered by businesses on the coast to cost money and inhibit economic performance due to its unreliability and frequent congestion.

Further Highways England identified the A27 between Lancing and the A24; between Arundel and the A284; between the A23 and Polegate; also around Chichester as being some of worst performing links in the country for safety issues.

[27] There are several sections of the A27 that fall inside the Highways Agency nationwide top 250 collision rankings:[28] At the Shoreham Airshow on 22 August 2015, a Hawker Hunter crashed into the A27 at Lancing, striking several vehicles and killing eleven people.

It then closely parallels the south coast and travels on via Fareham, Cosham, Havant, Chichester, Arundel, Worthing, Lancing, Shoreham-by-Sea, Hove, Brighton, Falmer, Lewes and Polegate where it then terminates at Pevensey in East Sussex.

Much of the road has been improved to dual carriageway standard, with the westernmost section of the trunk portion even having as much as four lanes plus a hard shoulder in each direction, and on a motorway alignment with grade-separated junctions.

[38] After the 'flyover' over the Adur, the A27 then runs past the Holmbush interchange (Shoreham-by-Sea) and on through the Southwick Hill Tunnel, at that point entering the City of Brighton and Hove, traditionally (though no longer administratively) part of East Sussex.

When Brighton and Hove Albion play at home this section can become congested due to its proximity to Falmer Stadium.

The South Coast Multi-Modal Study (SoCoMMS) recommended a dual carriageway, but the Highways Agency built it to a cheaper single-carriageway standard.