Engineering Commons^™

Frictional Performance Of Pavements And Estimates Of Accident Probability [Dec. 1980], James L. Burchett, Rolands L. Rizenbergs

Kentucky Transportation Center Research Report

Objectives of this study were to evaluate standard and experimental surfaces throughout Kentucky in terms of skid resistance and effects of traffic, and to provide criteria for judging suitability of these surfaces to satisfy requirements for skid resistance and economics. The effects of traffic were quantified by regression analysis and scatter of data. Criteria included an estimate of accident risks, effects of speed on skid resistance, and seasonal variations in skid resistance.

Pavements on low volume roads (less than 1,000 vehicles per day) maintained adequate skid resistances. Open-graded friction courses, with the possible exception of sections using phosphate slag aggregate, …

Interstate Safety Improvement Program, Jerry G. Pigman, Kenneth R. Agent, Charles V. Zegeer

Kentucky Transportation Center Research Report

The purpose of this paper was to prepare prioritized rankings of recommended improvements which could implemented for the Interstate Safety Improvement Program in Kentucky. Considerable detail is presented which documents analysis procedures used to determine sites, sections, and elements of the roadway in need of improvement. The average number of accidents per interchange, bridge, 1.6-km (1.0-mile) section, and 0.48-km (0.3-mile) spots were summarized for large urban, medium urban, and rural sections of the interstate system. At specified levels of statistical significance, critical numbers of accidents and critical accident rates were calculated to assist in identifying high-accident locations. A limited field …

Use Of Economic Analyses And Dynamic Programming In The Selection Of Projects For Resurfacing, Charles V. Zegeer, Kenneth R. Agent, Rolands L. Rizenbergs

Kentucky Transportation Center Research Report

The objective of this paper was to develop a dynamic programming procedure using economic analyses to assist in optimizing expenditures in pavement resurfacing programs. Benefit relationships were determined from expected accident reduction, improved comfort, time saving, fuel savings, and maintenance savings. The only cost input to the program was the resurfacing cost of each project.

Dynamic programming was adapted to the selection of projects for resurfacing in Kentucky. Over $8.4 million of additional user benefits would have been realized in 1976 if dynamic programming had been used in selecting projects. The benefit-cost ratio of sections selected for resurfacing by the …

Evaluation Of The Fhwa Highway Traffic Noise Prediction Procedure (Snap 1) [Oct. 1980], Kenneth R. Agent

Kentucky Transportation Center Research Report

Traffic noise prediction procedures are used in the design of new highways to determine if noise is limited to specific levels. A previous study evaluated the procedure outlined in NCHRP Report 117 and developed a correction factor which was incorporated into Kentucky's noise prediction procedure. This adjusted NCHRP 117 procedure has been used in Kentucky for the past several years. The Federal Highway Administration has developed a new procedure to predict traffic noise levels. The objective of this study was to evaluate the new prediction procedure, designated as SNAP 1.

Comparisons of measured and predicted noise levels showed that predictions …

The Effect Of Lane And Shoulder Widths On Accident Reductions On Rural, Two-Lane Roads, Charles V. Zegeer, Robert C. Deen, Jesse G. Mayes

Kentucky Transportation Center Research Report

The purpose of the study was to determine the effect of lane and shoulder widths on accident benefits for rural, two-lane roads and also to determine the expected cost effectiveness of widening lanes and shoulders. Information concerning geometries, accidents, and traffic volumes was obtained for over 25,000 km (15,000 miles) of roads.

Run-off-road and opposite-direction accidents were the only accident types found to be associated with narrow lanes and shoulders. Wide lanes had accident rates 10 to 39 percent lower than for narrow lanes. Wide shoulders (up to 2.7 m (9 feet)) were associated with the lower accident rates. Criteria …

The Operation Of An Electrical Heating System For Bridge Decks, Wm. Vernon Azevedo, Robert C. Deen, James H. Havens

Kentucky Transportation Center Research Report

The 9th-Street interchange with I 64 in Louisville, Kentucky, was designed and constructed with an automated electrical heating system for snow and ice removal. This report summarizes the operation of the heating system during the first four years. The system was capable of keeping the interchange free of ice and snow accumulation. The average daily slab temperature fell below 0°C (32° F) only on a few occasions. The average cost of electrical power for heating the interchange was $883 per day.

The Need For A Schema For The Classification Of Transitional (Shale) Materials, Robert C. Deen

Kentucky Transportation Center Research Report

The need for comprehensive information on the characteristics and behavior of earth materials has been recognized for many years, perhaps for as long as significant construction has taken place in and on the surface of the earth. In recent years, however, the magnitude and complexity of engineered construction has greatly increased, resulting in a corresponding increase in the need for information on the engineering properties of soil and rock materials for use in site selection, design, construction, and maintenance of major structures. Probably the most pressing need for such data is for use in preliminary considerations of site selection and …

Interpretation Of Dynamic Pavement Deflections, Gary W. Sharpe, Herbert F. Southgate, Robert C. Deen

Kentucky Transportation Center Research Report

In 1977, a methodology was .developed to evaluate pavement performance using dynamic (Road Rater) deflections. Since then, additional research has resulted in modifications ill the procedures. This paper presents the procedures presently used to evaluate flexible pavement structures. Background information is included on various procedures used by others. A sample set of data is presented and evaluated. A discussion is included on how the analyses of dynamic pavement deflections can be used to design overlays and in pavement management.

Modulus And Damping Of Asphaltic Concrete Using The Resonant Column, David L. Allen, Robert C. Deen

Kentucky Transportation Center Research Report

When analyzing flexible pavements or predicting their behavior by such means as elastic-layered theory or by finite elements, it is necessary to know the parameters that govern the behavior of the pavement components. One of the most important factors to consider is the modulus of the asphalt bound layers.

In the past two decades, one method that has seen increasing use in the determination of the moduli of engineering materials (particularly soils) is the resonant column. However, its use in determining the moduli cf asphaltic concrete has not been widespread or well documented. In this study, which was part of …

Frictional Performance Of Pavements And Estimates Of Accident Probability [Sept. 1980], James L. Burchett, Rolands L. Rizenbergs

Kentucky Transportation Center Research Report

Objectives of this study were to evaluate standard and experimental surfaces throughout Kentucky in terms of skid resistance and effects of traffic, and to provide criteria for judging suitability of these surfaces to satisfy requirements for skid resistance and economics. The effects of traffic were quantified by regression analysis and scatter of data. Criteria included an estimate of accident risks, effects of speed on skid resistance, and seasonal variations in skid resistance.

The analysis indicated that pavements on low volume roads (less than 1,000 vehicles per day) maintained adequate skid resistances. Open-graded friction courses, with the possible exception of sections …

Statewide Survey Of Skid Resistances Of Pavements (1979), Rolands L. Rizenbergs, James L. Burchett

Kentucky Transportation Center Research Report

Statewide survey of skid resistances continued in 1979 with the testing of 3,060 miles (4,930 km) of roads, including interstate and toll roads. During the two-year (1978 and 1979) cycle of testing, over 7,000 miles (11,270 km) of roads have been tested. Altogether, 560 miles (902 km) of roads had an average skid number of 28 or less. These pavements, in particular, should be considered for deslicking.

In 1978 and 1979, 28 percent of the state-maintained roads were surveyed. These roads carried 72 percent of all traffic on state-maintained roads.

Overlay Recommendations For I 64: Rowan, Carter, And Boyd Counties, Gary W. Sharpe, Herbert F. Southgate

Kentucky Transportation Center Research Report

A method was developed in 1978 for designing asphaltic concrete overlays for flexible pavements. This procedure utilizes Kentucky's theoretical flexible pavement design curves, estimates of pavement fatigue from traffic data, estimates of subgrade strengths, and estimates of the structural capacity of the existing pavement. Overlay designs were recommended for the asphaltic concrete pavement sections of I 64 in Rowan, Carter, and Boyd Counties. Road Rater deflection data were used to estimate the subgrade strength and the effective worth of the pavement structures. Pavement rutting and roughness were also considered in determining the final overlay thicknesses.

Input Guide: Kentucky Soils Data System, William J. Pfalzer

Kentucky Transportation Center Research Report

The Kentucky Soil Data System is a system of information storage intended to be used as both a design and research tool. It contains information relating to soil and rock (parent material) properties and allows for input of precise sample locations. The storage format is presented here. This report is intended primarily to aid in the input of data. A user-oriented report covering what information is available and how requests for information should be made is a forthcoming compliment.

Evaluation Of Reversible Lanes (Nicholasville Road; Lexington, Ky), Kenneth R. Agent, Jon D. Clark

Kentucky Transportation Center Research Report

The study involved an evaluation of reversibIe lanes as a method of increasing traffic flow. A unique feature of the system was allowing Ieft turns during the period of reversible flow, which meant that the left-turn lanes had to be moved and the signal displays shifted during operation and without interrupting traffic flow. The evaluation involved a comparison of data taken before and after installation of the reversible lanes. Types of data included delays, volumes, accidents, speeds, traffic conflicts, fuel consumption, and environmental factors.

Installation of the reversible lanes resulted in a significant savings in travel time in the peak …

Safety Improvement Program For Toll Roads, Jerry G. Pigman, Kenneth R. Agent, Joseph D. Crabtree

Kentucky Transportation Center Research Report

This report presents proposed safety improvements for Kentucky's toll roads. The primary methods of identifying needed improvements were an accident analysis and a field inventory. The accident analysis identified specific high-accident spots and sections. Also, accident rates were calculated for each toll road, and the types of accidents which had occurred in the 3-year period were summarized. A separate 10-year analysis of fatal accidents was made. The field inventory was used to identify roadway features which are now substandard and in need of upgrading. Also, high-accident spots and sections were investigated in the field. The benefits and costs for each …

Computerized Analysis Of Moisture-Density Data, E. Gregory Mcnulty

Kentucky Transportation Center Research Report

A mathematical algorithm is described and presented for estimating optimum moisture content and maximum dry density from moisture-density data obtained from ASTM Standard Test Methods D 698 and D 1557, which are often, even though incorrectly, referred to as the Standard Proctor Test and Modified Proctor Test, respectively. However, the algorithm can be used to analyze moisture-density data obtained by non-standard procedures. The algorithm is written in Fortran IV for use with the IBM 370/165 computer and Calcomp 663 drum plotter. Documentation of this computer program includes detailed input instructions, coding sheets, flow chart, variable descriptions, example problem, example …

An Analysis Of Bicycle-Related Motor Vehicle Accidents In Lexington, Ky, Kenneth R. Agent, Charles V. Zegeer

Kentucky Transportation Center Research Report

A 1978 report dealt with an analysis of statewide bicycle-related, motor-vehicle accidents in Kentucky. In this study, a more detailed analysis of one city (Lexington) was performed. Accidents in a seven-year period were analyzed to make a detailed summary of several years of accident data, compare the Lexington accident summaries with statewide statistics, identify high-accident locations, and recommend accident countermeasures.

The number of bicycle accidents in Lexington has increased in recent years; however, the bicycle accident rate for Lexington was lower than that found for many other major cities in Kentucky. The largest number of bicycle accidents involved male cyclists …

Analysis Of Weekday, Weekend, And Holiday Accident Frequencies, Jerry G. Pigman, Rolands L. Rizenbergs, Donald R. Herd

Kentucky Transportation Center Research Report

Trends in recent years have indicated that a significant percentage of weekend traffic is recreational and that the proportion of weekend trips is increasing. The "energy crisis" in late 1973, and the associated reduction in speed limit on March 1, 1974, affected weekend travel. A previous study by the Division of Research revealed that significant reductions in the number and rates of highway accidents, fatalities, and injuries coincided with the period of time generally referred to as the "energy crisis". Lower speeds were considered to be a primary factor in the reduction of accidents. An alteration in weekend and holiday …

Effect Of Interrupted Flow On Traffic Noise, Kenneth R. Agent, Charles V. Zegeer

Kentucky Transportation Center Research Report

The objectives of this study were to investigate the effect interrupted traffic flow has on traffic noise and to determine an applicable adjustment factor. No attempt was made to develop a specific equation to predict noise levels at interrupted flow locations.

The basic method of analysis consisted of comparing the field data taken at intersections to determine if the measured noise levels changed as a function of distance from the intersection. Results showed that interrupted flow conditions did not cause an increase in the L₁₀ and L_eq noise levels. Data taken before and after the installation of traffic …

Highway Research, James H. Havens

Kentucky Transportation Center Research Report

The Division of Research is responsible for:

1. Developing and carrying out a comprehensive research program on all aspects of transportation engineering and operations.
2. Maintaining lateral communication and coordination with other segments of the Department of Transportation regarding the development and conduct of research studies and special investigations of various operational and engineering problems.
3. Maintaining relations and cooperating with universities, professional organizations, and other transportation agencies; evaluating and reporting the research experiences of those agencies; and utilizing their findings directly or with further research for the benefit of the Kentucky Department of Transportation.
4. Maintaining an up-to-date library of research findings on …

Propagation Of Traffic Noise, Kenneth R. Agent, Charles V. Zegeer

Kentucky Transportation Center Research Report

The effects of various traffic, ground cover, and geometric conditions on traffic noise propagation were evaluated in this study. There were two general methods of data collection. The first method consisted of using as many as four sound-level meters and graphic-level recorders to take simultaneous recordings of the traffic stream; the second method involved a constant noise source using a random noise generator.

The L_1.0 noise level reduction per doubling of distance was found to increase substantially when the traffic volume was less than 1,000 vehicles per hour. Wind speed and direction were found to have a large effect …

Problem Identification For Highway Safety Plan, Jerry G. Pigman, Kenneth R. Agent, Joseph D. Crabtree

Kentucky Transportation Center Research Report

To comply with Section 402, Title 23 of the United States Code, each state is required to prepare an annual highway safety program. Kentucky's program, which includes identification, programming, budgeting, and evaluation of highway safety projects, is intended to have a positive impact on the reduction of traffic accidents. The first step in the program, problem identification, requires systematic, statistical analyses of accident records. In-depth analyses of accident data were performed, and 29 problem areas were investigated. Accident rates were found for counties and cities in the following categories: total accidents; fatal accidents; accidents by driver age and sex; and …

Traffic Accidents: Day Versus Night, Donald R. Herd, Kenneth R. Agent, Rolands L. Rizenbergs

Kentucky Transportation Center Research Report

A comparison of accidents during daylight and darkness was made for both rural and urban roads. Accident rates on all types of rural roads were higher during darkness than during daylight. Critical accident rates during darkness for various types of roads were calculated. In urban areas, a larger percentage of accidents occurred on wet pavements during darkness than during daylight, but there were no significant differences for rural roads. No significant difference was found between average speeds during conditions of daylight and darkness. On rural roads, imposition of the 24.6-m/s (55-mph) speed limit resulted in a reduction in accident rates …

Transverse Pavement Markings For Speed Control And Accident Reduction, Kenneth R. Agent

Kentucky Transportation Center Research Report

Pavement markings were placed ahead of a high-accident location (a sharp curve). Speed and accident studies were conducted before and after. The markings were placed so that drivers otherwise failing to reduce speed would see the markings at an increasing rate. The spacing of lines was intended to create an illusion of acceleration which would cause the driver to slow. Speed is perceived by the visual senses; drivers sense forces resulting from changes in speed but relate and associate speed to the visual field. In laboratory experiments, it has been shown that a driver's perception of speed can be varied …

Bicycle-Motor Vehicle Accidents In Kentucky, Kenneth R. Agent, Charles V. Zegeer, Robert C. Deen

Kentucky Transportation Center Research Report

The purpose of this study was to determine the characteristics associated with bicycle related, motor-vehicle accidents in Kentucky. It was found that cyclists 10 to 14 years of age were involved in the largest number of motor-vehicle related accidents. Males were involved in four times as many accidents a s females. Most accidents occurred in urban areas, mostly on residential streets. The majority of accidents resulted from errors by the cyclists. The most common type was the right-angle accident, but the leading types varied with cyclist's age. Several factors were related to age and accident severity. The accidents were summarized …

Evaluation Of The Fhwa Highway Traffic Noise Prediction Procedure (Snap 1) [Jan. 1980], Kenneth R. Agent

Kentucky Transportation Center Research Report

Traffic noise prediction procedures are used in the design of new highways to determine if noise is limited to specific levels. A previous study evaluated the procedure outlined in NCHRP Report 117 and developed a correction factor which was incorporated into Kentucky's noise prediction procedure. This adjusted NCHRP 117 procedure has been used in Kentucky for the past several years. The Federal Highway Administration has developed a new procedure to predict traffic noise levels. The objective of this study was to evaluate the new prediction procedure, designated as SNAP 1.

Comparisons of measured and predicted noise levels showed that predictions …

Occurrences Of Expansive Limestone In Kentucky, Ralph G. Coy, James H. Havens

Kentucky Transportation Center Research Report

No abstract provided.

Rutting Models For Asphaltic Concrete And Dense-Graded Aggregate From Repeated-Load Tests, David L. Allen, Robert C. Deen

Kentucky Transportation Center Research Report

The development of models to predict rutting in the asphaltic concrete and dense-graded aggregate layers of flexible pavements is reported. The models were developed from data obtained from repeated-load triaxial tests. Details of equipment and methodology are reported.

An asphaltic concrete base mixture was tested at temperatures of 45 F, 77 F, and 100 F. Longitudinal stress levels of 20 psi, 50 psi, and 80 psi were used. The tests were performed unconfined. Most of the specimens were tested to 10,000 cycles of loading. Three sequences of loading were used.

It is noted that temperature and stress level are extremely …

The Effect Of Truck Design On Pavement Performance, Robert C. Deen, Herbert F. Southgate, Jesse G. Mayes

Kentucky Transportation Center Research Report

When work is done on some materials systems, their internal geometric states are altered in such a way that they have the potential to "give back" work when the force is removed and the system returns to its original configuration. This stored energy is called strain energy. Strain energy density (strain energy per unit volume) is a function of the Young's modulus of elasticity and Poisson's ratio and the nine strain (or stress) components; but it is independent of the coordinate system. Material properties are input into the Chevron N-layer computer program to calculate the strain components.

Having calculated the …