The New Zealand Railways Magazine, Volume 3, Issue 2 (June 1, 1928)
The work of installing selective telephones and other necessary mechanical aids on the sections between Wellington and Marton (116 miles) and between Christchurch and Oamaru (152 miles) is well advanced, and it is hoped to be able to institute the latest Traffic Control System on these sections of our lines before this year is out.
In view of the adoption of the principle of Traffic Control on our lines, it is interesting to have particulars of how the traffic control system is succeeding in South Australia. Mr. W. A. Webb, Chief Commissioner of the South Australian Railways, has supplied figures to the “Railway Gazette” showing that an increase of one mile or more per hour in speed, equal to a saving of one hour per trip, has been obtained on the Cockburn line of their Peterborough division. Approximately, 3,600 trains are run on this section per annum, roughly 300 per month, which makes a saving of 3,600 hours—the equal of, approximately, £4,170—while the saving in train crews represents, approximately, £1,456 per annum; a total of £5,626 per annum.
The additional cost of the introduction of traffic control, in salaries and interest on capital cost of traffic control circuits, amounts to £3,126 per annum, so that the net saving per annum is equivalent to 17.5 per cent, on the capital investment, quite apart, of course, from the incalculable advantage to the travelling public and traders in time saved. These are big figures, but they are proved by similar examples of economics effected on other railways, and should suffice to show that the development of traffic control schemes in suitable localities can abundantly be justified by the results achieved.