|Length:||5.2 miles (8.4 km)|
|Meets:||A4148, B4149, A4041, A41, A4182, A457|
|Old route now:||A4252|
|Route outline (key)|
Starting at traffic lights on the southern section of the A4148 Walsall Ring Road, the A4031 heads south along the residential West Bromwich Road. The road soon widens to dual carriageway (at almost the exact point it moves from Walsall to Sandwell MB) before running under three consecutive motorway bridges at the northern tip of Ray Hall Interchange; the central bridge carries the M6 whilst the outer two are the M5 slip roads.
The road goes over the River Tame and Birmingham to Walsall railway line (by Tame Bridge Parkway station) and the Tame Valley Canal in quick succession. This section appears semi-rural but the houses soon come back and then a gyratory is reached, with the road returning to S2 status on the far side. It continues along Walsall Road to reach the Heath Lane Cemetery and a one-way system. Southbound traffic is forced left then has to stay in the right-hand lane to bear right to reach traffic lights on the A4041, where it TOTSOs right. The next set of lights sees northbound A4031 traffic TOTSO; it heads west to meet the B4149 then north alongside the cemetery to become two-way once again.
The A4031 takes primary D2 status from the A4041 (although it remains residential) and heads south along All Saints Way past Sandwell General Hospital into West Bromwich. On the northern side of the town centre it meets the grade-separated A41 and turns left to multiplex along that road for a few hundred yards. It regains its number at a GSJ with west-facing slip roads and then continues south, still D2 but no longer primary and only with a few houses fronting the road. The Midland Metro is crossed above Trinity Way station, named after this road, before a roundabout is reached and the A4182 is crossed. The D2 road then ends just before the road goes under the M5 and then we run through an industrial area. The two levels of the Birmingham Canal and the Stour Valley Line are crossed in quick succession before the road ends at a roundabout on the A457 to the west of Smethwick.
In the original 1922 road numbering, the A4031 number was allocated only to the section between the A41 at West Bromwich and the A457 near Smethwick; with the road between West Bromwich and Walsall being allocated the number B4165. The entire route was upgraded early on, as the 1932 Ten Mile Map shows the entire route as A-class.
Walsall and West Bromwich have since been bypassed, curtailing the A4031 in the first case (the road's northern end was on the A34 Wednesbury Road) and rerouting it in the second; whilst for a short while in the late 1970s, the route between West Bromwich and Smethwick was achieved via what is now the A4252.