Transportation Engineering Commons^™

A Guide To Preparing Research Reports And Technical Talks, Robert C. Deen

Kentucky Transportation Center Research Report

This manual has been prepared to provide guidance to writers of technical reports which are to be issued by the Division of Research, Kentucky Bureau of Highways. Concepts of technical report writing are presented. Specific instructions concerning the preparation and submission of reports for review are also presented. Appendices included provide rules for grammar, punctuation, etc. which cause engineer-writers particular problems.

Effects Of Water On Slope Stability, Tommy C. Hopkins, David L. Allen, Robert C. Deen

Kentucky Transportation Center Research Report

A brief state-of-the-art review of the effects of water on slope stability and the techniques for analysis is presented. The effective stress principle and basic considerations of slope stability, including design factors of safety, are discussed briefly. The derivations and effects of seepage forces and rapid drawdown on effective stress are also presented. Various conditions of external loading produce changes in effective stress. These changes are discussed and limiting conditions which should be analyzed are mentioned.

Limitations of total stress analyses are discussed in detail. It appears that, for soils having a liquidity index of 0.36 or greater (normally consolidated), …

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

Kentucky Transportation Center Research Report

Transverse pavement markings were placed ahead of a sharp curve having a high-accident history. Speed and accident studies were conducted before and after. The markings were placed so that drivers otherwise failing to reduce speeds while approaching the curve would see transverse lines on the pavement at an increasing rate. The spacing of lines was intended to create an illusion of acceleration which would cause the driver to slow. The results indicated that pavement markings can be an effective speed-control measure and reduce accidents. At the single site studied, the obedience of drivers to this type of hazard warning was …

Loads On Box Culverts Under High Embankments: Positive Projection, Without Imperfect Trench, Rick L. Russ

Kentucky Transportation Center Research Report

This report describes the instrumentation and measurements of settlements and pressures on two box culverts in Clark County, Kentucky, designed without the imperfect trench -- one for yielding and one for unyielding foundation conditions. The structures were primarily instrumented for comparison with three structures previously constructed in McCreary County, which were designed using the imperfect trench method. Pressures on the two structures in Clark County generally exceed the product of the unit weight of the overlying material and its height. The pressures on the culverts in McCreary County appear to be lower than expected -- indicating that the imperfect trench …

The Effectiveness Of School Signs With Flashing Beacons In Reducing Vehicle Speeds, Charles V. Zegeer

Kentucky Transportation Center Research Report

A detailed study of signs with flashers in school zones was conducted to determine their effectiveness in reducing the speeds of vehicles during times of pedestrian activity. Field investigations were conducted at all of the 120 flasher locations in Highway Districts 6, 7, and 9. About 14 percent of the flashers were inoperative. Such problems as non-uniform signing, hidden flashers, deteriorating signs and pavement markings, and poor sight distances were also found.

Speed studies were conducted at 48 locations. Average speed reductions were only 3.6 mph (1.6 m/s) during flashing periods. Signs and flashers at high-speed (55-mph (25-m/s)) locations increased …

First-Year Effects Of The Energy Crisis On Traffic In Kentucky (Rural Highways), Kenneth R. Agent, Donald R. Herd, Rolands L. Rizenbergs

Kentucky Transportation Center Research Report

The Arab oil embargo in mid-October 1973 curtailed availability of gasoline. Fuel conservation measures resulted in reduced travel and decreased traffic speeds. On March 1, 1974, posted speed was set at 55 mph (88 km/h) on rural highways in Kentucky. Traffic volumes, speeds, and accidents for the rural highway during the period known as the "energy crisis" and its after effects were compared to the corresponding period a year earlier.

Traffic volumes began to decline in December 1973 and continued through September 1974. Total travel in the 12 months through November 1974 decreased by 2.3 percent; traffic increased by five …

Accidents Associated With Highway Bridges, Kenneth R. Agent

Kentucky Transportation Center Research Report

The objective of this study was to identify those principal features of bridges which may be related to accident frequency and severity and to provide some further insights toward highway safety. Accident data from interstate and parkway (toll) routes and from primary and secondary systems were compiled and summarized. The major findings were:

1. Bridge-related accidents, particularly involving severe accidents, were significant percentages of the total accident experience on interstates and parkways.
2. There were fewer bridges per mile on the primary and secondary highway system and a lower percentage of bridge related accidents than on interstates and parkways.
3. The severity of …

First-Year Effects Of The Energy Crisis On Traffic In Kentucky (Rural Highways) [May 1975], Kenneth R. Agent, Donald R. Herd, Rolands L. Rizenbergs

Kentucky Transportation Center Research Report

The Arab oil embargo in mid-October 1973 curtailed availability of gasoline. Fuel conservation measures resulted in reduced travel and decreased traffic speeds. On March 1, 1974, posted speed was set at 55 mph (24.6 m/s) on rural highways in Kentucky. Traffic volumes, speeds, and accidents for the rural highway during the period known as the "energy crisis" and its after effects were compared to the corresponding period a year earlier.

Traffic volumes began to decline in December 1973 and continued through September 1974. Total travel in the 12 months through November 1974 decreased by 2.3 percent; traffic increased by five …

Evaluation Of Raised Pavement Markers, Jerry G. Pigman, Kenneth R. Agent, Rolands L. Rizenbergs

Kentucky Transportation Center Research Report

The purpose of this study was to evaluate the operational applicability of raised pavement markers and to determine their effectiveness with respect to brightness and durability. Seven different types of markers were evaluated. The primary application of markers in this study was as a supplement to lane lines. They were also used as a traffic control measure at lane drops, as delineation for hazardous curves, and as directional arrows.

Luminosity and durability were monitored for approximately one year. It was found that raised pavement markers can be a very effective method of roadway delineation. Markers evaluated had varying levels of …

Coding Urban Accident Locations, Donald R. Herd

Kentucky Transportation Center Research Report

This study reviews urban traffic accident location reference methods. Consideration is given to techniques used in other states and various cities. The needs for the Commonwealth of Kentucky were examined and a recommended location reference method and coding scheme are presented.

Discussion Of M.W. Witczak's A Comparison Of Layered Theory Design Approaches To Observed Asphalt Airfield Pavement Performance, Herbert F. Southgate, Robert C. Deen, James H. Havens

Kentucky Transportation Center Research Report

No abstract provided.

Vehicle Noise Survey In Kentucky, Kenneth R. Agent, Rolands L. Rizenbergs

Kentucky Transportation Center Research Report

Individual noise measurements were obtained on 10,500 motor vehicles operating on Kentucky highways. The roadways were selected to represent varied geometric and environmental conditions and posted speed limits. Percentages of automobiles and trucks exceeding a given level of noise were determined. As expected, noise levels of trucks were significantly higher than for automobiles, and larger trucks produced higher noise levels than smaller trucks. For any vehicle type, noise increased with an increase in speed limit.

At-Grade Intersections Versus Grade-Separated Interchanges (An Economic Analysis Of Several Bypasses), Kenneth R. Agent

Kentucky Transportation Center Research Report

In an effort to reduce traffic in central business districts, bypasses have been built to provide through traffic a circumferential route and also to ease the burden of traffic in downtown areas. In many cases, though, bypasses have created a serious accident potential because they were built with at-grade intersections and no access control. This has led to commercial developments along the bypass and congestion at major intersections. When congestion increases at an intersection, traffic signals must be installed; this increases vehicle operating and time costs and creates a rear-end collision potential. In some cases, the bypass circumvents a relatively …

Engineering Data System For Bedrock Occurrences And Properties, D. J. Hagerty, Robert C. Deen, M. W. Palmer, C. D. Tockstein

Kentucky Transportation Center Research Report

The initial work plan included the development of a classification system based on index tests. An investigation of previous works in classification of rock on the basis of index tests showed that a variety of classification systems utilizing many different index tests had been developed. However, this survey showed that no generally applicable system had been developed and that little communication had been established between field investigators, facility designers, and those in charge of construction and maintenance of facilities. Therefore, the initial plan for work was modified to include the development of a comprehensive methodology for evaluation of rock. The …

Temperature Distributions In Asphaltic Concrete Pavements, Herbert F. Southgate, Robert C. Deen

Kentucky Transportation Center Research Report

The straight-line relationship between temperatures at a given depth and the surface temperatures combined with 5-day average air temperatures appears to be as valid for upper New York state and Arizona as for Maryland. The main differences were in the annual ranges and annual mean temperatures. The concept for estimating pavement temperature distributions appears to be valid and may be used with confidence for estimating pavement temperatures at all latitudes and longitudes.

Pedestrian Accidents In Kentucky: 1972-1973, Charles V. Zegeer

Kentucky Transportation Center Research Report

Pedestrian accident data in Kentucky were analyzed for 1972 and 1973 on a rural, urban, and statewide basis. Results showed that about 1500 pedestrian accidents occur in Kentucky each year and cost over $11 million. About 30 percent of pedestrian accidents in rural areas and 4 percent in urban areas are fatal. Although about 78 percent of Kentucky's pedestrian accidents occur in urban areas, over 62 percent of the pedestrian fatalities occur in rural areas.

Specific characteristics of pedestrian accidents were identified and related to human, environmental, and time factors. Highway and street improvements and safety programs generally considered to …

Data Acquisition And Management For Rock Evaluation, M. W. Palmer

Kentucky Transportation Center Research Report

The primary goal of this thesis was the formulation of an integrated effort to collect, maintain, exchange, and evaluate engineering data on rock materials from a variety of information sources. The proposed rock evaluation program provides a data base of accumulated information by establishing procedures for characterizing rock, from specimen acquisition through indexing, classification and correlation studies of data, and the application of data for site selection, use tables, establishment of design parameters and alternatives, and maintenance of engineered facilities. The co-ordinated evaluation system detailed herein provides guidelines for implementation of an extensive system of data storage and retrieval to …

Effect Of Pavement Texture On Traffic Noise, Kenneth R. Agent, Charles V. Zegeer

Kentucky Transportation Center Research Report

Tire noise is one of the primary sources of highway noise, particularly at high speeds. Different types of road surfaces generate different noise levels. Noise data were collected on eight different surface types found in Kentucky. Noise measurements were made using a reference car, and noise recordings were obtained from the traffic stream. A reference truck was used for one test. It was found that portland cement concrete; Class I, Type A and A(Modified) bituminous concrete; chip seals; and open-graded, plant-mix seals were more or less "normal" surfaces in regard to generated noise. Sand-asphalt and Kentucky rock asphalt surfaces were …

Deflection Behavior Of Asphaltic Concrete Pavements, Herbert F. Southgate, Robert C. Deen

Kentucky Transportation Center Research Report

Deflection responses of a series of experimental test sections were obtained layer by layer during construction, upon completion of construction, and subsequent to construction. Deflections were obtained by use of Benkelman beams, the Road Rater, and the Dynaflect. Test results from one location within each test section were analyzed to determine which relationships were, or were not, meaningful. This was done as a pilot study and as a preliminary step toward final analysis of the data bank. The analyses are presented in this report.

Optimal Highway Safety Improvement Investments By Dynamic Programming [Dec. 1974], Jerry G. Pigman, Kenneth R. Agent, Jesse G. Mayes, Charles V. Zegeer

Kentucky Transportation Center Research Report

The process of determining which projects to implement under a given budget, and which to defer until later, is central to the planning and management of highway systems. With a limited budget for construction, maintenance, and safety improvements, investments which will produce the optimal benefits must be chosen. This is often impossible to accomplish without the aid of a computer because of the complexity of the problem. Dynamic programming has been tested and verified as an efficient method for selecting priority projects to derive maximum benefits. The applicability of dynamic programming to the safety improvement program is demonstrated in this …

Voidless Concrete Mixtures For Bridge Decks, Assaf S. Rahal

Kentucky Transportation Center Research Report

The purpose of this study was to modify concrete mix-design formulas to supplant all water over and above that needed for hydration with a non-evaporable material -- thus producing a no-void concrete. It was adjudged that a water-cement ratio of 0.244 would be practical for hydration of the cement. Several polymeric materials, asphalts, and oils were used to replace the excess mixing water. Success was achieved using two latexes and one epoxy. The use of these materials in concrete resulted in improved strength, reduction of air voids and permeability, and enhancement of resistance to corrosive chloride salts.

Fatigue Analysis From Strain Gage Data And Probability Analysis, Robert C. Deen, James H. Havens

Kentucky Transportation Center Research Report

The Central Bridge over the Ohio River between Newport, Kentucky, and Cincinnati, Ohio, was completed in 1891 and in 1972-73 was considered to be in danger of fatigue failure. A series of investigations were undertaken to determine the likelihood of failure and to estimate the time of probable failure. During the investigation, a methodology was developed to determine fatigue damage from a probability analysis of traffic data by reconstituting or synthesizing the load (traffic) history of bridges. Strain gage data obtained with Prewitt scratch gages and SR-4 resistivity gages were used to evaluate fatigue damage incurred by the Central Bridge.

Identification Of Hazardous Rural Highway Locations, John A. Deacon, Charles V. Zegeer, Robert C. Deen

Kentucky Transportation Center Research Report

An effective procedure was determined for identifying hazardous rural highway locations based on accident statistics. Multiple indicators of accident experience that are necessary include the number of fatal accidents, the total number of accidents, the number of effective-property-damage-only accidents, and the accident rate. Critical levels of these four indicators should vary from state to state depending on the nature of the local safety improvement program as well as local traffic and roadway conditions and prevailing attitudes toward highway safety. Specific recommendations are given for use in Kentucky. Critical accident rates are established using quality control procedures.

To identify hazardous highway …

Accidents On Rural Interstate And Parkway Roads And Their Relation To Pavement Friction, Rolands L. Rizenbergs, James L. Burchett, John A. Deacon, Cass T. Napier

Kentucky Transportation Center Research Report

Friction measurements were made with a skid trailer at 70 mph (31 m/s) on 770 miles (1240 km) of rural, four-lane, controlled-access routes on the interstate and parkway systems in Kentucky. Each construction project was treated as a test section. Accident experience, friction measurements, and traffic volumes were obtained for each. Various relationships between wet-weather accidents and skid resistance were analyzed. Averaging methods were used as a means of developing trends and minimizing scatter. A moving average for progressively-ordered sets of five test sections yielded more definite results. The expression of accident occurrence which correlated best with skid and slip …

Adaptation Of Aasho Interim Guide To Fundamental Concepts, Herbert F. Southgate, Robert C. Deen, James H. Havens

Kentucky Transportation Center Research Report

Using 1971 vehicle classification counts and truck weights from nine Kentucky locations, equivalent axleloads (EAL's) were calculated by several methods. Apparent discrepancies led to a review of axleload equivalency factors used to estimate either EWL's (equivalent wheel loads) or EAL's.

Axleload equivalencies are determined as the ratio of the number of repetitions of a standard or reference load to the number of equivalent (damage-wise) repetitions of the load in question. The choice of equivalency factors can result in as much as a 40-percent difference in calculated EAL's. Most of Kentucky's traffic is made up of axleloads less than 80 kilonewtons …

Evaluation And Modification Of The Traffic Noise Prediction Procedure For Kentucky Highways, Kenneth R. Agent, Charles V. Zegeer

Kentucky Transportation Center Research Report

Approximately 270 noise-level recordings were obtained at 39 highway sites and compared with the noise-level predictions obtained by the procedure outlined in NCHRP Report 117. The measured noise levels were computed in terms of the A-weighted L₁₀ value (level exceeded 10 percent of time) and then compared to the predicted noise levels. A significant discrepancy was found between predicted and measured noise levels; generally, the predicted values exceeded the measured values. Average error per location was 4.8 dBA; the maximum error was 13 dBA. A nomograph was devised to correct the predicted value; this nomograph involves observer-to-roadway distances, truck …

Highway Pavement Maintenance Costs And Pavement Type Selection, Donald C. Newberry Jr., Jesse G. Mayes, James H. Havens

Kentucky Transportation Center Research Report

A long-term analysis of pavement maintenance cost has been performed. The analysis does not include construction or resurfacing costs. The sample of pavement sections investigated were chosen to best represent the entire state. These sections were classified by pavement type; either bituminous concrete, portland cement concrete, or composite. The cost per lane mile (kilometer) per year was calculated for each pavement type by year and by age of pavement. Apparent differences in pavement maintenance costs between the two basic types of pavements were adjudged insignificant from the standpoint of determining pavement type. Because of poor or erroneous cost reporting, actual …

Relationships Between Roadway Geometrics And Accidents, Kenneth R. Agent, Robert C. Deen

Kentucky Transportation Center Research Report

Statewide average and critical rates of accidents were determined from 1970-1972 Kentucky accident records for each type of rural highway. Accident data, obtained from state police computer tapes, were summarized to give the number of accidents on each highway type as well as information on accident severity, road surface conditions, light conditions, road character, and type of traffic control. Four-lane undivided highways had the highest average accident rate; parkways (toll roads) had the lowest rate. The severity of accidents was related to types of accidents, highways, and traffic control and to safety belt usage. Accidents involving pedestrians were the most …

Rock Evaluation For Engineered Facilities, D. J. Hagerty, Robert C. Deen, M. W. Palmer, C. D. Tockstein

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, Direct testing of soil and rock can be utilized to furnish necessary information. However, both field and laboratory testing can be extremely expensive, particularly where testing must include applications of …

Bridge Decks Constructed For Increased Durability, Assaf S. Rahal

Kentucky Transportation Center Research Report

The experimental features incorporated in this study were compaction, brooming, and hi-layered construction. Broomed surfaces initially exhibited a higher skidding resistance than non-broomed surfaces: broomed surfaces, however, wear more rapidly. No conclusive evaluation could be made at this time of the bilayered system and of tests made on the concrete cores. Electrical measurements made on the decks indicated there was no active corrosion of the steel.