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The crushed stone industry in developed country like USA is the largest non-fuel, non-metallic mineral industry with respect to both total volume and value of production with about 901 million tons production valued at over 2 billion US $ in year 1975. The industry is geographically highly dispersed with all states. The stone production by individual states is proportional to population and industrial activity. There are over 5400 crushers in the USA located in urban, suburban and rural areas. Plans are either stationary or portable type in the capacity range varying from 100 tons to several thousand tons per hr. The various rock type processed are lime stone, granite, trap rock and sandstone. Important products include construction related material such as specified and unspecified construction aggregates and road stone, concrete aggregate, bituminous aggregate etc. As per USEPA data, the crushed stone industry was ranked third highest among the nations 56 no. of largest particulate source emitting category industries in the year 1975.

The prices of the crushed stone in USA vary from place to place depending on the transportation involved, costs of raw material, size of crushed stone etc. Typically the prices range (converted in equivalent Rs.) from Rs.90 to Rs.370/ton for 1.5” size stones and about Rs.250/- per ton for 0.75” size stones. Typically the transportation costs range from Rs.25/- to Rs.75/- per ton from the quarry to city. As the professional manufacturer of complete sets of mining machinery, such as ore beneficiation, Henan Hongxing is always doing the best in products and service.

The financial profile of typical stone crusher plants indicates the industry sector operates on an average profitability of about 7%, the industry if capital intensive, depreciation and depletion represent major sources of funds for capital expansion and a major portion of the industry’s assets is tied up in working capital, primarily inventories and accounts receivable.

Crushed stone is generally distributed directly from the quarry to the user with no intermediary involved. It is readily available in most metropolitan areas because transportation and distribution are predominantly by truck. Inventories are held almost entirely at the quarry location because double handling would be prohibitively expensive, and customers maintain only sufficient inventory to ensure uniform production rates over a pre-determined time. Typically the crushers operate for 9 months in a year in USA.

In this chapter, researchers describe an overall assessment process that allows practitioners to objectively compare the safety consequences of performing a particular work activity either during daytime hours or as night work. Specifically, the process focuses on calculating the expected crash costs over the entire period of time required to complete the work activity under either scenario. By focusing on the total time required to complete a particular work activity, analysts can account for the differences in the duration of each work zone set-up during the day or at night. Obviously, longer work durations each night allows a project to be completed over fewer nights. The process relies on the availability of normal daytime and nighttime roadway crash rates for a particular facility, which the analyst then modifies by a percent increase to account for the additional crashes expected to occur as a result of having the work zone in place on that facility. The percentage increases used in the analysis are based on the previously-documented results of crash studies at several work zones where night work occurred, as well as observational studies of erratic maneuvers under daytime and nighttime queuing conditions.

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