with a third transmitter further in rear of the signal increasing the effectiveness to 100 mph (160 km/h). When installed in conjunction with signal controls such as 'double blocking' (i.e. two red signal aspects in succession), TPWS can be fully effective at any realistic speed.

TPWS is not the same as train stops which accomplish a similar task using electro-mechanical technology. Buffer stop protection using train stops is known as 'Moorgate protection'