(former B664) towards Rockingham
The second incarnation of the B664 was a short B-road through the Northamptonshire town of Corby.
The road started on the A43 to the north of Stanion and headed northwestwards along Geddington Road and Stanion Lane to reach Corby town centre, where it met the A427 opposite St John the Baptist Church.
There was a short multiplex along the A427 along the High Street before the B664 regained its number by turning right along The Jamb, which soon became Rockingham Road. After crossing the railway line it continued northwestwards out of town, ending on the A6116 to the south of Rockingham itself.
The B664 was originally unclassified but gained its number around 1930, making it a rare example of a pre-1935 reuse of a number. However, the number was short-lived as the road was upgraded to Class I status in 1935, when it became an extension of the A6116.
Upgrades to Corby's road network at the end of the 20th century mean that only the western end of the former B664 is still part of the A6116. The section east of Corby town centre has been much improved and renumbered A6086, whilst the remainder is unclassified.