The section of line between Egginton Junction and Friargate was then acquired by the Train Control Group of the BR Research Division, as a suitable test track. It was singled between Friargate and Mickleover, but in 1973 the line was cut back to Mickleover since the eastern end of the track bed had been earmarked for the new A38 trunk road. Thereafter the line was used as a test track until 1990 when the A516 feeder road to the A50 by-pass was built over the trackbed and the line was closed and lifted.