TSRs

Probably by altering the codes fed to the rails...

TSR's on the Victoria Line require trains to be driven in coded manual, they are not operated automatically !

This means the highest set TSR is usually 22mph, as a train in coded manual will not generally be able to exceed this speed. Lower TSR's obviously require the driver to drive at the stated TSR speed.

Whist a train in ATO can be braked to a lower speed or stopped and switched over between stations it is customary for a TSR to be applied from the station starter. Trains may NOT resume ATO between stations so after the end of the TSR is reached the train is restricted to 22 or so MPH until the next station starter.

Additional delays are caused, as in coded manual a lunar white aspect must be treated as a stop signal. It is only a proceed aspect to a train in ATO mode, so trains end up much further apart.

For all these reasons TSR's on the Victoria Line tend to be very short lived and are subject to rapid rectification after close of traffic.