H.—4o,

F. PETROL-CONSUMPTION. The following table shows a classification of the manner in which petrol was consumed in the Dominion during the last ten calendar years :—

The total gallons are calculated from the quantity of motor-spirits 011 which petrol-tax was paid. A further tremendous increase in motor-vehicle petrol-consumption took place in 1937 as compared with 1936, the previous peak year, the figures showing an increase of 10,000,000 gallons. 3. ROADS. A. ALTERATIONS IN RESTRICTIONS AS TO LOADING AND SPEED OF HEAVY MOTOR-VEHICLES. For some time past the Department has been engaged on an investigation into the effects of wheel-loads on road surfaces. Due primarily to improved tire equipment of heavy vehicles, including a considerable reduction in tire-pressures, it has been found that roads will now carry greater loads without necessitating any increase in the strength of the surface. It will be appreciated that it is desirable to permit as great a load as possible, consistent with adequate protection of the road surface. A conference of representatives of road-controlling authorities and the various organizations of the users of heavy motor-vehicles was held during the year to discuss the position in regard to the restrictions placed upon heavy motor-vehicles under the Heavy Motor-vehicle Regulations, 1932. Following upon the discussions at this conference of interested parties, and upon the investigations carried out by the Department, the following amendments to the regulations were effected : — (i) The Class Two classification, prescribing maximum gross loads of 8 tons in the case of two-axled heavy motor-vehicles and 12 tons in the case of multi-axled vehicles, was removed, and the roads formerly classified in Class Two are now deemed to be unclassified. Little advantage has in the past been taken of this class, only some seven hundred miles of road being so classified. (ii) The gross load-limits for two-axled heavy motor-vehicles have been increased as follows : — Class Three : From 6| tons to 7 tons. Class Four: From tons to 5 tons. Class Five : From 3 tons to tons. Corresponding increases have been made in respect of the permissible axle loads.

2—H. 40.

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Estimated Consumption of Petrol. Calendar Year. By Motor-vehicles Other-i.e Engines (i.e., Petrol on which Aeroplanes &c. (Petrol Total all Duty was paid). °" w f h,ch Refunds of ' r -Duty were made). Gallons. Gallons. Gallons. 1928 .. .. .. .. 41,457,150 2,057,940* 43,515,090* 1929 .. .. .. .. 56,575,840 3,650,040 60,225,880 1930 .. .. .. .. 62,821,479 3,907,900 66,729,379 1931 .. .. .. .. 55,202,983 5,286,000 60,488,983 .1932 .. .. .. .. 49,861,976 5,495,479 55,357,455 1933 .. .. .. .. 51,293,572 5,400,000 56,693,572 1934 .. .. .. .. 55,991,831 6,100,000 62,091,831 1935 .. .. .. .. 62,807,535 6,483,600 69,291,135 1936 .. .. .. .. 72,107,051 6,685,600 78,792,651 1937 .. .. .. .. 82,110,905 7,339,000 89,449,905 * Excludes an unknown amount of petrol on which duty was not paid.