The B2237 follows the pre-bypass route of the A24 through the centre of Horsham, although the road was numbered A2400 in between.
The road starts at a roundabout on the A24, on the edge of the grounds of Warnham Court, and heads eastwards into town. The road is briefly rural before we reach the edge of the urban area and then continue through the suburbs. After the B2180 heads off to the left at traffic lights we skirt the edge of Horsham Park and then reach the town centre and traffic lights on the A281 relief road.
There's a brief multiplex to the right to another set of lights where the A281 turns right and the B2237 continues ahead to regain its number. We're still on the D2 relief road at this point but after a couple of roundabouts – and a couple of supermarkets – we rejoin the old A24 and the road becomes S2 again as we leave town. We cross the River Arun and then climb the residential Worthing Road before going over the railway line on the edge of town.
We continue south along a leafy lane and then pass a golf course. After a set of traffic lights giving access to a park-and-ride facility the B2237 ends at a roundabout where it rejoins the A24.