Video Evaluation of Highway Drainage Systems, HR-317, 1991

Since 1978 the concept of longitudinal edge drains along Iowa primary and Interstate highways has been accepted as a cost-effective way of prolonging pavement life. Edge-drain installations have increased over the years, reaching a total of nearly 3,000 mi by 1989. With so many miles of edge drain installed, the development of a system for inspection and evaluation of the drains became essential. Equipment was purchased to evaluate 4-in.-diameter and geocomposite edge drains. Initial evaluations at various sites supported the need for a postconstruction inspection program to ensure that edge-drain installations were in accord with plans and specifications. Information disclosed by video inspections in edge drains and in culverts was compiled on videotape to be used as an informative tool for personnel in the design, construction, and maintenance departments. Video evaluations have influenced changes in maintenance, design, and construction inspection for highway drainage systems in Iowa.

Total Cost of Transportation Analysis of Road and Highway Issues, HR-388, 2002

In the administration, planning, design, and maintenance of road systems, transportation professionals often need to choose between alternatives, justify decisions, evaluate tradeoffs, determine how much to spend, set priorities, assess how well the network meets traveler needs, and communicate the basis for their actions to others. A variety of technical guidelines, tools, and methods have been developed to help with these activities. Such work aids include design criteria guidelines, design exception analysis methods, needs studies, revenue allocation schemes, regional planning guides, designation of minimum standards, sufficiency ratings, management systems, point based systems to determine eligibility for paving, functional classification, and bridge ratings. While such tools play valuable roles, they also manifest a number of deficiencies and are poorly integrated. Design guides tell what solutions MAY be used, they aren't oriented towards helping find which one SHOULD be used. Design exception methods help justify deviation from design guide requirements but omit consideration of important factors. Resource distribution is too often based on dividing up what's available rather than helping determine how much should be spent. Point systems serve well as procedural tools but are employed primarily to justify decisions that have already been made. In addition, the tools aren't very scalable: a system level method of analysis seldom works at the project level and vice versa. In conjunction with the issues cited above, the operation and financing of the road and highway system is often the subject of criticisms that raise fundamental questions: What is the best way to determine how much money should be spent on a city or a county's road network? Is the size and quality of the rural road system appropriate? Is too much or too little money spent on road work? What parts of the system should be upgraded and in what sequence? Do truckers receive a hidden subsidy from other motorists? Do transportation professions evaluate road situations from too narrow of a perspective? In considering the issues and questions the author concluded that it would be of value if one could identify and develop a new method that would overcome the shortcomings of existing methods, be scalable, be capable of being understood by the general public, and utilize a broad viewpoint. After trying out a number of concepts, it appeared that a good approach would be to view the road network as a sub-component of a much larger system that also includes vehicles, people, goods-in-transit, and all the ancillary items needed to make the system function. Highway investment decisions could then be made on the basis of how they affect the total cost of operating the total system. A concept, named the "Total Cost of Transportation" method, was then developed and tested. The concept rests on four key principles: 1) that roads are but one sub-system of a much larger 'Road Based Transportation System', 2) that the size and activity level of the overall system are determined by market forces, 3) that the sum of everything expended, consumed, given up, or permanently reserved in building the system and generating the activity that results from the market forces represents the total cost of transportation, and 4) that the economic purpose of making road improvements is to minimize that total cost. To test the practical value of the theory, a special database and spreadsheet model of Iowa's county road network was developed. This involved creating a physical model to represent the size, characteristics, activity levels, and the rates at which the activities take place, developing a companion economic cost model, then using the two in tandem to explore a variety of issues. Ultimately, the theory and model proved capable of being used in full system, partial system, single segment, project, and general design guide levels of analysis. The method appeared to be capable of remedying many of the existing work method defects and to answer society's transportation questions from a new perspective.

Report on Rest Area Water Systems for Interstate Highways, 1967

Introduction: As part of the roadside development along the Interstate Highway System, the Iowa State Highway Commission has constructed eight pair of rest area facilities. Furthermore, two pair are presently under construction with an additional two pair proposed for letting in 1967. An additional nine and one-half pairs of rest areas are in the planning phase, a grand total of 45 rest Brea buildings. The facilities existing were planned and designed in a relatively short period of time. The rest area facilities are unusual in terms of water use, water demand rates, and the fact that there are no applicable guidelines from previous installations. Such facilities are a pioneering effort to furnish a service -which the travelling public desires and will use. The acceptance and current use of the existing facilities shows that the rest areas do provide a service the public will use and appreciate. The Iowa State Highway Commission is to be congratulated for this· pioneering effort. However there are problems, as should be expected when design of a new type of facility has no past operating experience to use as a guide. Another factor which enters is that a rest area facility is quite different and rather unrelated to engineering in the highway field of practice. Basically, the problems encountered can be resolved into several areas, namely 1) maintenance problems in equipment due to 2) insufficient capacity of several other elements of the water systems, and 3) no provisions for water quality control. This study and report is supposed to essentially cover the review of the rest areas, either existing and under construction or letting. However, the approach used has been somewhat different. Several basic economically feasible water system schemes have been developed which are· adaptable to the different well capacities and different water qualities encountered. These basic designs are used as a guide in recommending modifications to the existing rest area water systems, anticipating that the basic designs will be used for future facilities. The magnitude of the problems involved is shown by the fact that the projected water use and demand variations of each rest area building is equivalent to the water supply for a community of about 100 people. The problems of proper operation and maintenance of an eventual thirty to forty-five such facilities are gigantic. For successful operation the rest area water systems must have a high degree of standardization and interchangeability of all elements of the water systems, even if it means a limited degree of over-design in some rest area facilities.