From Roader's Digest: The SABRE Wiki
|The B4159 is the Class II road to the left of the map|
|From:||Darlington Street, Wolverhampton (SO911986)|
|To:||Salop Street, Wolverhampton (SO911984)|
|Length:||0.2 miles (0.3 km)|
|Met:||A449, A454, A41|
|Route outline (key)|
The original use of the B4159 number was for School Street, in Wolverhampton city centre.
Quite why School Street was allocated a B classification in 1922 is unknown as its only function at the time was as a short, though busy, city centre street. It is so short that it can barely be seen on 1920s MoT Mapping, with the green B-road colouring being almost invisible.
At that time, the southern section of School Street south of Salop Street did not exist, and so the route of the A449 in the city centre was via Worcester Street and Victoria Street. Whilst it would make sense for the A449 to then continue north via North Street, the traditional route northwards to Five Ways, it seems to be the case that the original allocation multiplexed with the A454 along Darlington Street before proceeding north along Waterloo Road leaving B4159 as a short stub.
However, in the 1960s upon the construction of the southern section of School Street, the B4159 number was swapped with that of A449, with A449 taking the logical path from Waterloo Road to Penn Road via School Street (with the southbound section using the gyratory system via Pitt Street and Worcester Street), and B4159 being moved to the northern part of Worcester Street and Victoria Street before terminating on the A454 at Queen Square. This meant that the B4159 was finally declassified in 1986, in common with all roads within the city centre when the final section of the Inner Ring Road was completed.