Technically, the railways of New Zealand are far more advanced than most New Zealanders would appear to believe. In the field of track engineering New Zealand railway engineers are making excellent progress, and main lines are being relaid or constructed to very high standards permitting heavier traffic and higher speeds, yet costing less to maintain. The standard rail now being laid in main lines weighs 91 lb per yard, compared with the old standard of 70 lb introduced in 1901. Increasing use is being made of specialised machinery for the laying and maintenance of track, and rails are now welded together into long lengths by the electric flash-butt method. Traffic flow is also being steadily improved by means of modern signalling and communications equipment. Electric colour-light signals are replacing the old mechanically operated semaphores, and the classic signal cabin, with its huge manually worked levers, is being replaced by compact all-electric or electronic installations requiring only finger-tip control.

On some heavy-traffic routes the electric train-tablet system – used since 1901 to regulate the passage of trains over single-line sections between stations – has been replaced by a modern remote-control system known as C.T.C. (Centralised Traffic Control). C.T.C., which makes use of colour-light signals and electrically operated points, enables a train controller at a central control station to regulate the flow of traffic in both directions over sections of single line up to 100 miles in length. It permits a smoother operation of a larger number of trains than could be handled in a given period by the tablet system, and enables a reduction to be made in the number of employees required for signalling purposes at wayside stations. New Zealand was the first country outside the North American continent to adopt C.T.C., and since 1938 more than 400 route miles of line have been equipped. The longest individual sections are Frankton-Taumarunui (90 miles), on the North Island Main Trunk line, and St. Leonards – Oamaru (74 miles) on the South Island main line. Preparations are in hand for eventual installation of C.T.C. on the whole of the North Island Main Trunk line between Paekakariki and Frankton, and at the time of writing only 60 miles of single-track line on this route remain under tablet control.