|Distance:||12.6 miles (20.3 km)|
|Meets:||A4053, B4544, B4110, A444, B4082, B4029, B4112, B4065, B4114, M69, A5, B590|
|Former Number(s):||A46, A447|
|Route outline (key)|
The route's original starting point was Bishop Street on the then A423, but today it begins on the north side of Coventry's Pool Meadow bus station, as the southern section of White Street: part of a gyratory system and grade-separated junction with the A4053 ring road. After uncoiling itself from this complex, the B4109 heads northeastwards along Stoney Stanton Road, crossing the Coventry Canal twice before meeting the A444 at a roundabout.
In Bell Green it crosses the B4082 at a junction made up of half a roundabout and a T-junction (where the B4109 TOTSOs left and the B4082 right). It then heads north, soon going under the M6 and crossing the Oxford Canal to enter open country.
After going under the West Coast Main Line we enter the village of Bulkington and meet the B4029 at a mini-roundabout by the recreation ground. The latter route becomes the dominant partner in a multiplex east through the centre of Bulkington, turning right at a mini-roundabout where it meets the B4112 before the B4109 regains its number by taking the next road left.
The B4109 now heads east along Wolvey Road through Ryton before going over the M69. Some ponds (part of a fishery) are passed before the road enters Wolvey itself and reaches a double mini-roundabout where it meets the B4065. This is the original end of the B4109; the other road here is the original line of the A46. That road was downgraded in the 1970s when the parallel motorway was built and at the same time the B4109 was extended. The B4109 turns left at the roundabouts and then, soon after passing the church and leaving the village, TOTSOs left (the through road here – which is in fact the old A46 – is today unclassified). From this point on, the B4109 follows the pre-M69 route of the A447.
The B4114 is soon crossed (with the B4109 having priority). After the next road to the left the B4109 bends to the right. It leaves the ex-A447 here; that went straight ahead but the road was severed by the M69. Soon afterwards a roundabout is met, where the road crosses both the A5 and the M69; this is junction 1 of the motorway.
Now in its last stretch, the B4109 continues north and soon rejoins the old road (although there is no actual junction). It runs through the southern suburbs of Hinckley before going under the Nuneaton to Leicester railway line on the edge of the town centre. It ends immediately afterwards at a roundabout where it meets the B590. The A447 used to continue straight ahead.