Constitutional amendments and laws passed in the late twenties added some mileage to the original State road system and authorized the construction of supplementary or feeder roads, so that the entire State system of roads at the present time comprises approximately 16,000 miles, divided about equally between the main State system and the supplementary roads. The total road mileage of the State is approximately 116,000. It is estimated that there are an additional 7,200 miles of streets in cities of over 2,500 population, some of which are used by the highways passing through these cities. The present laws of the State prohibit the use of State funds for the construction of roads through towns and cities of more than 2,500 population; therefore, little has been done in the improving, widening, and resurfacing of city streets which are used as a part of the State highway system. The commission, however, has followed the policy of bypassing or relocating roads through congested areas on most of the main highways, which has relieved to some extent the bottlenecking of traffic. The 16,000-mile State road system as now constructed is distributed in the different counties of the State. There is a decided need for the expansion of the feeder-road system, and the improvement of the main roads in the congested areas, especially on those which were built in the twenties. These are mostly of 18-foot width, have relatively short sight distance, and poor alinement. We have before us, therefore, a big problem in widening a large percentage of our roads and in bringing them to the proper presentday standards. In some of the congested areas we have widened the roads to three and four lanes, and in a few places we have built fourlane divided highways. Based on statements of facts, I believe it has been conclusively shown that Missouri represents a fair cross section of the Nation; therefore it qualifies as a typical State. What about its highway needs? In 1938 the Missouri State Highway Department, in cooperation with the Public Roads Administration, conducted a complete and comprehensive highway survey to determine present and future State highway needs. This survey, published in book form early in 1939, a copy of which is being filed with your committee, served as a guide to the selection of improvements up to and including 1941 when highway work was interrupted by the national emergency. The CHAIRMAN. The Special Report on Missouri State Highway Needs, 1939, referred to, will be placed in the committee's files and is made a part of the printed hearings by reference only. Mr. BROWN. Since that time construction operations, except for access roads and the improvement of a few sections of highways considered essential to the war effort, have been discontinued, thus bringing about the necessity for a restudy of conditions to take into consideration accelerated deterioration of the entire highway system caused by curtailment of necessary annual reconstruction and the continuous burden of heavy wartime traffic. Some idea of the completeness of the detailed studies carried out is indicated by the following brief description of the scope of the 1938 survey. Future traffic trends.-In order to estimate future needs intelligently, information on expected traffic increases is essential. Informa tion collected by the State-wide Planning Survey concerning motorvehicle registration, gasoline consumption, average mileage per car per year, increases in power unit efficiency, population trends, and motor-vehicle ownership, were studied and future predictions made. Traffic hazards.-Traffic accident experience records were studied to determine the causes of accidents, as well as the most logical procedure to follow to reduce their number in the future. Adequate design standards were recommended for adoption, and estimates of cost necessary to the use of such standards were included in the over-all cost of future work. Surface types and pavement width. The selection of surface types and pavement width, including the necessary number of lanes, depends upon traffic volume, percentage of heavy commercial vehicles and concentration of heavy loads. After making a detailed analysis of traffic volumes, a formula was developed taking into consideration transportation costs per vehicle-mile to determine justifiable surface types on various classes of roads. The following conclusions were reached and used in later computations of costs. Granular surfaces are satisfactory for traffic volumes up to 150 vehicles per day. Low-cost dustless surfaces are necessary and justifiable for traffic volumes between 150 and 600 vehicles per day. Intermediate type surfaces are necessary for traffic volumes between 600 and 900 vehicles per day. High-type surfaces are necessary and justifiable for traffic volumes in excess of 900 vehicles per day. Dual-lane high-type pavements are justifiable for traffic volumes in excess of 3,000 vehicles per day. Obsolescence. There are several reasons why it may be necessary to reconstruct, widen, or otherwise modernize existing highways, the most important of which are obsolescence and deterioration, or a combination of both. A road becomes obsolete when the alinement, grades, widths, and sight distances are such that they do not facilitate the free movement of traffic without congestion or danger. When deterioration reaches a point which causes excessive maintenance and the road has only a rough and hazardous riding surface, reconstruction is necessary. In an attempt to determine the probable date of reconstruction brought about by either or both of these conditions, a study of the physical condition of highways was made and combined with a surface condition survey. Physical characteristics.-Data for this survey were obtained from two sources: Construction records from the State highway department files, and field investigations. All substandard sections of highway were recorded, together with width and type of surface, as well as hazards not inherent in the road itself. This study resulted in the preparation of a map of the complete highway system showing the location and degree of deficiency of each road in the system, a section of which is shown in figure 11 of the report. It was used principally to determine priority for elimination of unsatisfactory conditions, and I wish at this point to insert a copy in the record. The CHAIRMAN. Very well. (The map referred to as figure 11 is as follows:) Mr. BROWN. A surface condition survey was made in order to ascertain the location of all road surfaces which were deteriorating. In 1930, the State highway department, in cooperation with the Portland Cement Association, made a survey of all concrete pavements constructed prior to 1928. At that time all indications of material deterioration or structural failure were noted. The pavements included in this survey which were still in service in 1938 were resurveyed and the progress of deterioration and failure recorded. These data, correlated with traffic information, were then used in conjunction with road-life studies to determine the life expectancy of all rigid and semirigid surfaces. Road life. The purpose of the road-life study is to determine the average service life, rate of retirement, and annual cost of each type of roadway improvement. From the construction and retirement tables which were prepared, it was possible to estimate, on the basis of past experience, the mileage of each surface type which will be retired and the miles of resurfacing and reconstruction necessary annually to maintain the present surfaced mileage in serviceable condition. The average service lives of the various surfaces were developed from the actual construction experience of the highway department. The results are as follows: High-type surface___ Intermediate-type surface_. Perpetuated by maintenance. High-type surfaces include portland cement concrete pavement, sheet asphalt on rigid bases, brick, and asphaltic concrete. Intermediate type surfaces include all dustless surfaces not included in high-type surfaces. Using the estimated service life of surfaces, charts were prepared to indicate necessary annual replacements, as shown in figures 12 and 13 of the report, which I desire to submit for the record at this time. The CHAIRMAN. That may be done. Mr. BROWN. Highways are subject to the same factors of obsolescence and deterioration as any other property. It is the age of the important heavy traffic sections of the highway system which accounts for the fact that the factors of obsolescence and deterioration are now beginning to be felt in a serious way. These factors must be given first consideration in any highway construction program as it is of first importance to conserve the existing investment before new investments in the form of extensions or special developments are incurred. The estimated requirements from 1939 to 1961 rapidly become reconstruction, replacement, and normal improvement of existing facilities rather than continued extension. All of the factors heretofore described were compiled and correlated to determine future highway needs with considerable accuracy for a period of 10 years. Additional cost data were compiled to cover a second 10-year period. Data for the second 10-year period were prepared simply to give some idea of revenue required over a long period |