D.—l.

The average expenditure on maintenance per mile per annum on the whole highways system, by the Board and local authorities, since 1924, is shown in the following table Average Average Expenditure v Expenditure Year - per Mile Year ' per Mile per Annum. per Annum. £ £ 1924-25 .. .. .. .. 51-7 1930-31 .. .. .. .. 103-1 1925-26 .. .. .. .. 73-2 1931-32 .. .. .. .. 92-5 1926-27 .. .. .. .. 111-9 1932-33 .. .. .. .. 70-7 1927-28 .. .. .. .. 119-9 1933-34 .. .. .. .. 78-6 1928-29 .. .. .. .. 100-1 1934-35 .. .. .. .. 100-3 1929-30 .. .. .. .. 128-6 1935-36 .. .. .. .. 122-4 Construction, Reconstruction, and Surfacing. The expenditure from the Construction Fund for the year 1935-36 was £428,024, an increase of 32 per cent, on the corresponding expenditure for the preceding year. The season just past was not a good one for bituminous surfacing in most districts owing to wet weather being generally experienced. During the year ended 31st March, 1936, 152 miles of main highways were reconstructed, formed, or widened, 358 miles of dustless surfacing, including stage construction, were completed, of which 245 miles were sealing, and 93 miles plant-mix or road-mix pavement. The table below shows the extent and types of - work carried out on the main highways system by the Board and local authorities since the Board commenced active operations in 1924.

A description of some of the major works is as follows : — Auckland District. Auckland-Wellington Main Highway, Waipa County Division.—This work, extending over a length of 30 miles and estimated to cost £162,000, consists of improving the alignment, remetalling, and plant-mix surfacing, together with the reconstruction of several bridges in reinforced concrete, and the renewal of all culverts in permanent materials. As this highway is one of the most heavily trafficked in the Dominion, a high standard has been set. The minimum radius of curvature is 10 chains and vertical sight distances 500 ft. Good progress has been maintained and at least half of the work completed. The surfacing comprises a cushion course of sand or inferior metal on the subgrade, followed by a 6 in. consolidated thickness of crushed basalt rock. A mulch-dressing of chippings is then applied, and maintained for at least three weeks under traffic, after which a first-seal coat of No. 1 tar is laid. Finally a plant-mix surface, f in. thick, of densely-graded aggregate with M.C. 3 binder is planed on with a long base planer. Tauranga District. Rotorua County, Sealing.—Rotorua is one of the most important tourist resorts in the Dominion, and in the holiday season there is a large influx of visitors. It has been recorded that 2,400 vehicles traversed the main road between 5 p.m. and 5 a.m. on one day. The original surfacing was for the most part the natural pumice, which in dry weather dispersed clouds of dust, to the great discomfort and danger of motorists. The Board undertook some 20 miles of surface sealing in the area at a cost of £26,000. It was necessary to utilize local materials, as much as possible, as stone-chipping, which had to be obtained from remote areas, cost as much as £1 6s. per cubic yard. The pumice itself consists of fine fragments of glass, with very little cohesion, and is very absorbent, When the surface was

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„ n rr, i Road-and- Bituminous | t>„„.*.i Formation Gravelling Tar and plant . mix Macadam Bituminous' P °!" „ . pa Year - w .r d m f n Bl * UII ?. m0US Bituminous (Penetra- Concrete. ! p —* Brid § e8 - Widening. Metalling. Sealing. Surfacing. tion). Concrete. Miles. Miles. Miles. Miles. Miles. Miles. Miles. Ft. 1924-25.. .. 19 63 6 .. 6 .. .. 2,434 1925-26.. ..45 88 16 45 4 6 5,168 1926-27.. .. 174 151 35 .. 38 12 16 6,408 1927-28.. .. 173 133 83 .. 34 .. 6 7,760 1928-29.. .. 224 185 122 .. 51 14 11 9,482 1929-30.. .. 173 179 133 .. 39 31 12 7,547 1930-31.. .. 130 128 95 .. 41 14 9 11,175 1931-32.. .. 139 69 129 32 9 3 4,062 1932-33.. .. 56 45 72 .. 8 .. .. 3,178 1933-34.. .. 44 28 75 .. 7 .. 1 4,988 1934-35.. .. ! 113 69 172 27 3 .. 2 6,641 1935-36.. .. | 152 98 245 91 2 .. .. 8,718 1 j 1 Totals .. 1,442 : 1,236 1,183 118 306 84 j 66 77,561 I 1 L