The B1400 is a largely rural B-road in north Lincolnshire. Not included in the 1922 Road Lists, the route – or at least that part of it running west of the small town of Kirton in Lindsey – was first classified in about 1925. The short section south-east of Kirton was added in the 1950s to give the road its current length of seven miles.
The route starts on the B1205 and heads north-west into Kirton in Lindsey, skirting the airfield, which lies to the left. At a T-junction we meet the B1398 and turn right to follow this road for half a mile through Kirton. At a crossroads by the Queen's Head public house we turn left and the B1400 resumes. We descend Spa Hill and the road turns north-north-westward before going under the Retford to Grimsby railway line by the station, which lies on the very edge of the town and sees very few passenger trains: only six a week (three in each direction) and only on Saturdays!
The road now continues across flat countryside, heading north-westward overall but with several very sharp corners along the way. After some three and a half miles we pass a Wildlife Trust nature reserve to our right: a series of lagoons created by the extraction of sand. The exact location of the public entrance to this site almost qualifies for "closely guarded secret" status, however! A little further on we come to Brigg Lane, onto which we must turn left, after giving way, to reach the end of our route, about a mile to the west, at a T-junction on the A159 at the south end of the village of Messingham.