imported to Hok Yuen Quarry for crushing to meet the unabated demands for bitumen coated materials.
4.52. Formation and drainage of the plant areas continued at Diamond Hill and work commenced on the construction of plant foundations and the installation of equipment and services.
4.53. At Mt. Butler Quarry the manufacture and use of ammonium nitrate and fuel oil mixtures was introduced as a routine means of blasting rock. Steps were also taken to place quality control of bituminous coated materials on a more regular basis with the provision of a small laboratory and the recruitment of a laboratory assistant for the quarry.
4.54. Most of the seven private quarries let on long-term contracts and administered by the Quarry Section, were affected by the general drop in demand for quarry products due to the recession in private building.
4.55. Details of production at the Government quarries are given in Appendix N.
4.56. A review of some seventy private quarries on short-term leases was carried out with a view to gauging efficiency and to determine which should be placed on a long-term contract basis. A report on the supply of quarry products and future demands throughout the Colony was also under preparation.
General
TRAFFIC ENGINEERING DIVISION
Chief Engineer:
CHAN Nai-keong, A.M.I.C.E., A.M.I.T.E. (Acting)
4.57. Traffic flow on the roads of the Colony continued to grow and the number of new vehicles registered during the year was substantially the same as last year. During the year, however, Police records were brought up to date and vehicles which had not been re-registered deleted therefrom. The total number of vehicles now registered as compared with last year's records does not therefore indicate the increase in new vehicles registered during the year. This explains the apparent flattening of the graph of vehicle registration given on page 40.
4.58. In addition to vehicle registration the graph on page 40 shows the general trend of statistics for population, road mileage, and accidents over the past decade. Both population and road mileage
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