The B198 is a short road on the west side of the Hertfordshire town of Cheshunt.
The route starts at a roundabout on the B156 on the western edge of the town and heads anti-clockwise along Lieutenant Ellis Way, a D2 road which forms a southwestern bypass of Cheshunt. This road was opened in the 1970s with the number A1241 but appears to have been downgraded quickly. It is named after 2nd Lt. John D Ellis, pilot of a US Air Force B24 Liberator bomber who crashed in farmland near Cheshunt in 1944. It it thought (although not known for certain) that the pilot intentionally steered the aeroplane away from residential areas but died in the crash as a result - see Herts Memories for more detail.
In the early 2010s a roundabout was added to the middle of this formerly rural dual-carriageway link road to provide access to a new school. It's then not long before we reach a roundabout on the A10, where the road ahead is numbered A121.
The route appears to end here, but if we track north along the A10 for three quarters of a mile we arrive at a set of traffic lights where we may turn right onto College Road, which is a further, detached portion of the B198 taking us into the town centre, reached in just over a third of a mile at the Old Pond roundabout on the B176 (ex-A10).
The road running west from the lights on the A10 at which we turned right is sometimes erroneously mapped as being part of the B198. It is in fact, however, the Hertfordshire C164, which started out as the B156, briefly became a part of the A121, and later the A1010. Following construction of the present line of the A121 in the 1990s the road was downgraded to dissuade through traffic going through the centre of Cheshunt and it was at this point that the section east of the lights was reclassified as an extension of the B198.