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sufficient bridging available for emergencies, which are not uncommon under present bridging and traffic conditions. It has been used for forty bridges, and is at present in use on thirty of these, and may expect to remain in some cases up to five years. Apart from construction in New Zealand of bridges in permanent materials, tenders were called in Britain for three manufactured steel bridges, and these should arrive shortly. Also, Callender-Hamilton bridging is being obtained for the Pelorus and Canvastown Bridges on the Blenheim-Nelson highway. Some twenty-one secondhand, 66 ft., wrought-iron truss spans are being acquired ex New Zealand Bailways strengthening programme for three highway bridges. By various temporary means and the steps outlined, together with an improvement in material supplies, if the construction and skilled man-power situation can be improved for bridge-work, the position can gradually be remedied. LOADING ON HIGHWAYS During recent years the Board has drawn attention to the great increase in both the numbers and the individual loads of heavy motor-vehicles, and has stressed the effect which this development is making on our highway system and thus on our national economy. Beference to registration figures shows a striking position. Whereas in 1939 only 3 per cent, of the total number of heavy motor-vehicles were registered in the 1\ to 8 tons class, by 1949 this figure has risen to 31 per cent. In the multi-axled vehicle classes, from 8 to 10 tons, the increase over the same years has been from 6 per cent, to 22 per cent. ; while in the heaviest class, consisting of vehicles over 10 tons in gross weight, the figures have risen from 3-|- per cent, to 8 per cent. The significance of these figures lies in the fact that the 7-| to 8 ton vehicle is the heaviest two-axled vehicle of conventional design which up till now it has been possible to operate over a highway. Operators are naturally going to the legal loading limit to provide economic and competitive transportation. Unfortunately they have been all too frequently in practice going beyond the limit. The same position obtains for the multi-axled vehicles with their increasing numbers working to the class limits, and beyond, for the various highways. As stated in last year's report, the Board had endeavoured to make a realistic approach to the problem of loadings and, after investigation, had made detailed recommendations to the Transport Department. As a result, new loading regulations are now to be introduced at an early date, and in preparation for this a review is being made of the classification or load-carrying capacity of all highways. In the result, with the rationalizing of anomalies which have existed and with a general up-grading of highways, there will be advantage to operators. On the other hand, our highway assets must be protected and preserved within our ability to pay for their reasonable maintenance and there must be strict exercise of control and enforcement of these more modern and liberalized regulations. Strict control and enforcement has been promised the Board by the Transport Department. Unless this control is effective and unless penalties are sufficiently severe to act as a deterrent against overloading, extensive failure and excessive and costly maintenance will continue on our highways. CENTRE-LINE MARKING OF HIGHWAYS The usual centre marking of highways consists generally of a 4-in.-wide fine, 18 in. long, with 4 ft. 6 in. gap to the next mark. This, however, is not fully standard, and other lengths of line and gap exist. This marking costs by machine marking from £7 to £l2 per mile, and has to be done, for satisfactory marking, two and sometimes three times per year. In view of the cost of centre-line marking, and despite the generally temporary nature of the types of surfacing used in this country, the use of more permanent markings may be economic. To this end centre-line marking has been carried out, chiefly in Southland, utilizing white quartzite pebbles. These have been generally 4 in. wide and 12 in.

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