Measurement of Pavement Surface Variations, July 1974

The measurement of pavement roughness has been the concern of highway engineers for more than 70 years. This roughness is referred to as "riding quality" by the traveling public. Pavement roughness evaluating devices have attempted to place either a graphical or numerical value on the public's riding comfort or discomfort. Early graphical roughness recorders had many different designs. In 1900 an instrument called the "Viagraph" was developed by an Irish engineer.' The "Viagraph" consisted of a twelve foot board with graphical recorder drawn over the pavement. The "Profilometer" built in Illinois in 1922 was much more impressive. ' The instrument's recorder was mounted on a frame supported by 32 bicycle wheels mounted in tandem. Many other variations of profilometers with recorders were built but most were difficult to handle and could not secure uniformly reproducible results. The Bureau of Public Roads (BPR) Road Roughness Indicator b u i l t in 1941 is the most widely used numerical roughness recorder.' The BPR Road Roughness Indicator consists of a trailer unit with carefully selected springs, means of dampening, and balanced wheel.

Final Report-Freeway Operations Analysis of I-80 to I-29 Interchange, January 1974

A t the request of the Iowa State Highway Commission, the Engineering Research Institute observed the traffic operations at the Interstate 29 (1-29) and Interstate 80 (1-80) interchange in the southwest part of Council Bluffs. The general location of the site is shown in Figure 1. Before limiting the analysis to the diverging area the project staff drove the entire Council Bluffs freeway system and consulted with M r . Philip Hassenstab (Iowa State Highway Commission, District 4, Resident Maintenance Engineer at Council Bluffs). The final study scope was delineated as encompassing only the operational characteristics of the diverge area where 1-29 South and 1-80 East divide and the ramp to merge area where 1-80 West joins 1-29 North (both areas being contained within the aforementioned interchange). Supplementing the traffic operations scope, was an effort to delineate and document the applicability of video-tape techniques to traffic engineering studies and analyses. Documentation was primarily in the form of a demonstration video-tape.

A Computerized Method for the Hydrologic Design of Culverts, February 1974

Nationwide, about five cents of each highway construction dollar is spent on culverts. In Iowa, average annual construction costs on the interstate, primary, and federal-aid secondary systems are about $120,000,000. Assuming the national figure applies to Iowa, about $6,000,000 are spent on culvert construction annually. For each one percent reduction in overall culvert costs, annual construction costs would be reduced by $60,000. One area of potential cost reduction lies in the sizing of the culvert. Determining the flow area and hydraulic capacity is accomplished in the initial design of the culvert. The normal design sequence is accomplished in two parts. The hydrologic portion consists of the determination of a design discharge in cubic feet per second using one of several available methods. This discharge is then used directly in the hydraulic portion of the design to determine the proper type, size, and shape of culvert to be used, based on various site and design restrictions. More refined hydrologic analyses, including rainfall-runoff analysis, flood hydrograph development, and streamflow routing techniques, are not pursued in the existing design procedure used by most county and state highway engineers.

The Minerals of Iowa, 1974.

This book contains maps, colored pictures and detailed information of minerals found in Iowa. It includes the localities of where they can be obtained and the characteristics by which they can be identified. This is part of the Iowa Geological Survey Educational Series 2.

Plan Now to Help Iowa Celebrate the Nation's 200th Anniversary, 1776-1976,1974.

This brochures has information on the celebration of the American Revolution and describes the duties of the Bicentennial Commission and State Heritage '76 committees. It tells how a person can help with the celebration and lists the members of the Iowa American Revolution Bicentennial Commission.

The Indians called it beautiful land : your quick-fact book : Iowa, a place to grow,1975.

A pocket sized brochure containing brief information on Iowa's history, industry, agriculture, tourism, quality of life, transportation, exports for the world market, people, education and basic facts.

Effect of Wildlife Highway Warning Reflectors on Deer-Vehicle Accident, December 1984

he number of deer-vehicle accidents in Iowa and around the country has steadily increased during the past 30 years. This i s basically due to: ( 1 ) increased volume of traffic; 12) an expanding network of hard surface roads, especially 4 lane interstates; and (3) a general increase in deer populations. Initidtion of a 55 MPH speed limit in 1974 and gasoline shortages in 1975 reduced deer-vehicle accident rates briefly, but since 1975, rates have continued to climb. Various methods of reducinq these accidents have been attempted in other states. These include: instal lation of rc?flective devlres, deer crossing signs, fencing, underpasses, clearing right--of--waysa,n d controlled hunting to reduce deer population s i z e . These methods have met with varying degrees of success, depending on animal behavior, deet- population fluctuations, method used, topoyr-aphy, road-side vegetation, traffic patterns, and highway configuration. This project was designed to evaluate a new ntethod of reducing deer-vehicle accidents. There are qenerally 4 important aspects of deer-vehicle accidents: danger to human l i f e , vehicle damage, loss of a valuable wildlife resource, and cost of processing accident reports. In !owe, during 1983, there were over 15,OOC) reported deer--vehicle accidents and probably many more that were not reported (Gladfelter 1984). The extent of human injury or death in Iowa i s not known, but studies in southern Michigan show that human injur ies occurred in about 4% of the deer-vehicle accidents (A1 lcn and MrCullough 1976). T h i s would indicate that in Iowa there could have been 200 human injury cases from deer-vehicle accidents i n 1983. These injuries usual 1 occur from secondary collisions when motorists try to avoid a deer on the highway, and hit some other object Vehicle darnaye from these accidents can into thousands of dollars because of the high speed involved and the size of the animal. The total amount of vehicle damage occurring in Iowa is unknown, but if the average vehicle damage was between $500-$800 per accident, estimated property damage would be between $2 1/2--$4 million annually. The value of deer lost in these accidents cannot be estimated, but recreational potential of this natural resource is surely diminished for hunters and wildlife enthusiasts. Also, there ir a great deal of money spent by governmental agencies for manpower to process accident reports and remove dead animals from highways.

PC Concrete Texturing, R-246, 1975

Skid resistance is a major concern of the safety engineer since wet pavement conditions are present for approximately 18% of the total accidents in Iowa according to studies by the Traffic and Safety Department. Many of these accidents may be influenced by the low skid resistant quality of the pavement. The size, shape, type, and arrangement of the concrete's particles interrelate with each other in a complex manner to give us frictional resistance. The purpose of this investigation was to determine which method of texturing provides the best skid resistance properties on portland cement concrete pavement.

Evaluation of the Argentine Nondestructive Test for Determining Concrete Compressive Strength, R-269 and MLR-75-2, 1975

The compressive strength of concrete is an important factor in the design of concrete structures and pavements. To assure the quality of the concrete placed at the project, concrete compressive cylinders are made at the jobsite. These cylinders undergo a destructive test to determine their compressive strength. However, the determination of concrete compressive strength of the concrete actually in the structure or pavement is frequently desirable. For this reason, a nondestructive test of the concrete is required. A nondestructive test of concrete compressive strength should be economical, easily performed by field personnel, and capable of producing accurate, reproducible results. The nondestructive test should be capable of detecting the extent of poor concrete in a pavement or structure due to improper handling, placement, or variations in mixing or materials.

Engineering Study Automating Iowa's Speed Monitoring Program, HR-228, 1983

Excessive speed on State and County highways is recognized as a serious problem by many Iowans. Speed increases both the risk and severity of accidents. Studies conducted by the FHWA and NHTSA have concluded that if average speeds were increased by five MPH, fatalities would increase by at least 2,200 annually. Along with the safety problems associated with excessive speed are important energy considerations. When the national speed limit was lowered to 55 MPH in 1974, a tremendous savings in fuel was realized. The estimated actual savings for automobiles amounted to 2.2 billion gallons, an average of 20.75 gallons for each of the 106 million automobiles registered in 1975. These benefits prompted the Federal-Aid Amendment of 1974 requiring annual State enforcement certification as a prerequisite for approval of Federal-aid highway projects. In 1978, the United States D.O.T. recommended to Congress significant changes in speed limit legislation designed to increase compliance with the national speed limit. The Highway Safety Act of 1978 provides for both withholding Federal-aid highway funds and awarding incentive grants based on speed compliance data submitted annually. The objective of this study was to develop and make operational, an automatic speed monitoring system which would have flexible capabilities of collecting accurate speed data on all road systems in Iowa. It was concluded that the Automatic Speed Monitoring Program in Iowa has been successful and needed data is being collected in the most economical manner possible.

An Investigation of Concrete Setting Time, R-265 (MLR-75-4), 1975

A water reducing and retarding type admixture in concrete is commonly used on continuous bridge deck pours in Iowa. The concrete placed in the negative moment areas must remain plastic until all the dead load deflection due to the new deck's weight occurs. If the concrete does not remain plastic until the total deflection has occurred, structural cracks will develop in these areas. Retarding type admixtures will delay the setting time of concrete and prevent structural cracks if added in the proper amounts. In Section 2412.02 of the Standard Specifications, 1972, Iowa State Highway Commission, it states, "The admixture shall be used in amounts recommended by the manufacturer for conditions which prevail on the project and as approved by the engineer." The conditions which prevail on the project depend on temperature, humidity, wind conditions, etc. Each of these factors will affect the setting rate of the plastic concrete. The purpose of this project is to provide data that will be useful to field personnel concerning the retardation of concrete setting times, and how the of sets will vary with different addition rates and curing temperatures holding all other atmospheric variables constant.

Planning for disaster : local government's role in civil preparedness,1975

This handbook deals with the duties and responsibilities of a mayor of a city, a member of a county board of supervisor or a sheriff of a county from the standpoint of their relationship with a county/municipal civil defense and emergency planing administration.

An Evaluation of Concrete Bridge Deck Surfacing in Iowa (with corrections), MLR-75-1, 1975

Iowa has been using low slump concrete for repair and surfacing of deteriorated bridge decks on a routine basis since the mid 1960'2. More than 150 bridges have been resurfaced by this method with good results. A study was initiated in 1973 to evaluate 15 bridges resurfaced with low slump concrete, and one bridge resurfaced with latex modified concrete. The evaluation includes an assessment of concrete physical properties, chloride penetration rates, concrete consolidation, and riding qualities of the finished bridge deck. Results indicate that the overall properties of these two types of concrete are quite similar and have resulted in a contractor option concerning which system shall be used on bridge deck repair/resurfacing projects.

Durability of Concrete as Affected by Variations in Air and W/C Ratio, R-258, 1975

Many times during the past four years we have seen ranges in the durability factor for a single coarse aggregate source that were too great to be explained by variations in the coarse aggregate alone. The durability test (ASTM C 666 Method B) as presently used is a test of the concrete system rather than that of a particular coarse aggregate. An informal study of current durability factor data indicates that w/c ratio and/or percentage of air may be critical to beam growth and durability factor. The purpose of this project, R-258, is to determine the extent w/c ratio and air content variations have on beam growth and durability factor when other factors including coarse aggregate gradation are held constant.

A Computer Based Information System for County Equipment Cost Records, Interim Report, HR-173, 1975

This report describes the work accomplished to date on research project HR-173, A Computer Based Information System for County Equipment Cost Records, and presents the initial design for this system. The specific topics discussed here are findings from the analysis of information needs, the system specifications developed from these findings, and the proposed system design based upon the system specifications. The initial system design will include tentative input designs for capturing input data, output designs to show the output formats and the items to be output for use in decision making, file design showing the organization of information to be kept on each piece of equipment in the computer data file, and general system design explaining how the entire system will operate. The Steering Committee appointed by Iowa Highway Research Board is asked to study this report, make appropriate suggestions, and give approval to the proposed design subject to any suggestions made. This approval will permit the designer to proceed promptly with the development of the computer program implementation phase of the design.