PREVIOUS QUARTER BASE--index for each quarter as compared with 100.0 for each preceding quarter. 1Base for composite index, 1957-59, involves 3,641,885,000 cubic yards of roadway excavation 154,953,000 square yards of Portland cement Index figures for 1922 through 1950 are simple mathematical conversions from the 1925-29 base to the 1957-59 base. They were derived from 40516-U.S. Dept. of Co-DC--1961 EXHIBIT F DEPARTMENT OF COMMERCE, BUREAU OF PUBLIC ROADS, Washington, D.C., June 23, 1958. Circular memorandum to: Regional and division engineers. Subject: Availability of aggregates for construction. Replies have been received in accordance with the memorandum of November 5, 1957, same subject. They have been very helpful in reviewing the situation with regard to the supply of aggregates and in some cases actions have been initiated that will assist in increasing the known sources of supply and thereby facilitating the highway construction program and possibly reducing the cost thereof. A brief summary of the replies is as follows: 1. "Is the known supply of aggregates ample to take care of the anticipated needs for highway purposes for at least the next 15 years?" The supply is not considered adequate in Colorado, Mississippi, or Oklahoma. In Florida it is adequate for at least 10 years; Kansas adequate in the eastern one-third of the State; Nebraska is short on crushed rock; New Hampshire expects a gravel shortage; New York expects a shortage of fine aggregate and bank-run gravel; Oregon short in the southwest and northwest part of the State; Pennsylvania short of coarse aggregate in the northwest part of the State and fine aggregate in the central part; Virginia short of coarse aggregate in Suffolk district; other States have minor shortages of certain types of aggregates in small areas. 2. "Are the sources of available aggregates within economical shipping distances?" The replies were most interesting to study in regard to what is considered an economical shipping distance. In States with plentiful aggregate sources, 2 to 5 miles might be considered the limit, while a State with general shortage or large shortage areas might consider up to 100 miles economical. It would seem that where the longer hauls are required the States should consider every alternate means of upgrading, stabilizing, or other means of reducing the quantity needed for these long hauls. 3. "What action has been taken or is planned to inventory existing supplies of aggregates and to find and explore new sources?" Most States have kept some records of the known and used sources of supply. Many have kept such records and also have done some exploring for new sources in the vicinity of proposed construction; among them are Arizona, Arkansas, Colorado, Florida, Georgia, Idaho, Illinois, Indiana, Kansas, Kentucky, Michigan, Minnesota, Mississippi, Missouri, Nevada, New Hampshire, New Mexico, North Carolina, Oklahoma, Oregon, Texas, Utah, Vermont, Virginia, Washington, and Wisconsin. Commercial producers are active with or without State assistance in Alabama, Arkansas, Florida, Iowa, Maryland, New Jersey, New York, North Carolina, Ohio, Hawaii, and the District of Columbia. 4. "Would the State be interested in undertaking a comprehensive cooperative survey of existing and potential aggregate sources?" Some interest in a cooperative survey has been expressed in Arizona, Colorado, Connecticut, Florida, Idaho, Iowa, Kansas, Louisiana, Minnesota, Mississippi, New Hampshire, New York, Oklahoma, Oregon, South Dakota, Utah, Vermont, Washington, and Hawaii. Cooperative soil surveys have been completed in New Jersey and Rhode Island. Cooperative surveys of aggregates are now underway in Maine, North Dakota, Oklahoma, Oregon, Washington, and West Virginia. It is anticipated that cooperative surveys will soon be started in Arizona, Vermont, and Utah. Rather complete independent surveys have been made in Michigan, North Carolina, Virginia, and Wyoming among others. 5. "What measures have been or can be taken to conserve the best quality aggregates by making maximum use of those of lower quality?" The most common reply to this query and mentioned by 25 States was the use of medium quality material for subbase and conserving high quality material for bases and surfaces where greater shear strength is required. Several States advised that this was done for economy rather than for conservation. The net result in either case is the same-smaller quantities of higher quality material are required and the construction cost is lowered without reducing the strength of the pavement. EXHIBIT I HIGHWAY CONSTRUCTION USAGE FACTORS FOR CEMENT, BITUMENS, CONCRETE PIPE, AND CLAY PIPE, 1958-60 DISCUSSION This is the sixth in a series of tabulations showing highway construction usage factors for cement, bitumens, concrete pipe, and clay pipe for 3-year periods. The first of the series was based on the years 1953, 1954, and 1955 and the fifth of the series covered the years 1957, 1958, and 1959. An important phase in highway construction planning is the estimating of future requirements for materials in order that industry may be geared to supply such materials. Of the various materials used in highway construction, steel and aggregates constitute the largest elements of cost, together amounting to more than 50 percent of the cost of all materials and supplies and about 30 percent of the total construction cost (not including the cost of right-of-way and engineering). The approximate comparable percentages for the materials in this tabulation are as follows: The usage factors for cement, bitumens, and the pipe items are intended to aid producers, manufacturers, and suppliers of these commodities and related industries, as well as highway contractors, engineers, and economists in planning to meet the needs of the expanded highway construction program in the United States. These factors when applied to expected contract construction expenditures for both Federal-aid and non-Federal-aid highway construction, will generally result in reasonably accurate estimates of requirements. The data used in the development of the usage factors are supplied by contractors for projects on the Federal-aid primary system (including Interstate). Investigations have indicated that, for comparable standards of design, material usage factors for non-Federal-aid work do not differ appreciably from those developed for Federal-aid construction. Information for computing Federal-aid secondary factors, by States, is not currently reported. It is recommended, therefore, that the State secondary factors on the tabulation of November 1957, covering the period 1954-56, be used for reasonably accurate estimating purposes. It should be recognized that the factors shown for individual States, in some instances, may not be truly representative of normal usage because of being based on low volumes of work and/or temporary disproportionate percentages of the three major classifications of highway construction, i.e., grading and drainage, surfacing, and structures. An outstanding and unusual example of this is shown for concrete pipe on the Interstate Urban System in Arizona, where there were a relatively small number of projects, all of which consisted primarily of drainage work. In most States, however, during the 3-year period, the volume of work is large enough and the type distribution is of proper proportion to reflect fairly representative usage factors. As in previous tabulations of the series, the elimination of data for the first year of the last edition and the inclusion of data for the most current complete year resulted in some significant changes in the factors for some States. Generally the U.S. average factors for cement, bitumens, and concrete pipe have decreased to some extent as compared to the previous issue, while those for clay pipe have increased. |