This article is about the original A278, which ran between East Grinstead and Horsham. For the current A278, a road in the Medway Towns area between Rainham and Bredhurst, see A278.
The A278 was a rural A-road in north Sussex. The landscape in this area is now somewhat different!
The road started on the A22 at Felbridge, just north of East Grinstead, and headed west through Copthorne and Three Bridges into Crawley, where it crossed the A23 in the town centre. The road continued west shadowing the railway line west of Crawley. It entered Horsham along Crawley Road and continued into the town centre where it ended on the A281 in the Market Square.
In 1935 the entire A278 was renumbered as a western extension of the A264. Significant development in the area since then have rerouted that road somewhat. The A264 still follows the ex-A278 as far as Copthorne - but then the A278 takes the A2220 through Crawley (although the very centre is now unclassified). The road into Horsham is now largely the B2195, although there are still some unclassified sections and the Market Square is now pedestrianised.