Transportation Engineering Commons^™

Treatment Of Narrow Medians On Four-Lane Rural Roadways, Jerry G. Pigman, Kenneth R. Agent

Kentucky Transportation Center Research Report

The objective of this study was to investigate alternatives to paved mountable medians that have been used in the past on sections of four-lane, partially controlled access roads where right-of-way is restricted. These mountable medians present obvious operational problems due to the 3-inch difference in height as compared to the through lanes. In addition, construction and maintenance problems are associated with mountable medians because of the height differential.

A telephone survey of 16 states was conducted to determine their policy for separation of rural four-lane roads with partial control of access and narrow medians. Accident analyses comparing roads in Kentucky …

Use Of Post Delineators On Interstates, Kenneth R. Agent, Jerry G. Pigman

Kentucky Transportation Center Research Report

The objectives of this report were to investigate 1) the potential benefits of using flexible posts for post delineators and 2) the possibility of not requiring post delineators on sections of interstate-type highways where recessed markers are installed.

It is recommended that post delineators should only be used when the design curvature is 1.5 degrees or more, and the spacing should be based on the formula given in Table III – 1 of the MUTCD. Data obtained concerning the performance of flexible posts do not support widespread use at this time. A testing program should be developed to obtain an …

Use Of Nondestructive Testing To Prevent Failures Of In-Service Metal Bridges, Theodore Hopwood Ii, Robert C. Deen

Kentucky Transportation Center Research Report

The failure of metal bridges, subject to in-service fracture problems mainly caused by fatigue, may be prevented or minimized by performance of periodic nondestructive testing. Attendant factors that justify funding for such inspections include the potential for bridge failure, the consequences of bridge collapse, risk analyses, and inspection strategies. Factors that affect structural integrity include structural design, construction quality, and service loadings.

Details of a computer/strain-gage system capable of obtaining strain-gage data from critical structural elements are described. Data are processed to determine the stress-range distribution, number of stress cycles, resolved mean stress range, need for structural inspection, critical crack …

Delineation Of Horizontal Curves, Kenneth R. Agent, Tom Creasey

Kentucky Transportation Center Research Report

The objective of this study was to investigate the ability of various traffic control measures to delineate horizontal curves so drivers would perceive the curve and slow to an appropriate speed and then be provided guidance through the curve. Pavement delineation (raised pavement markers, transverse stripes, or rumble strips) and shoulder delineation (post delineators and chevron signs) were used. A laboratory test found that a post delineator configuration in which the distance from the post to the pavement edge and the post spacing remained constant while the height of the delineator on the post increased made a curve appear sharper …

A Generalized Slope Stability Computer Program: User’S Guide For Hopk-I, Tommy C. Hopkins

Kentucky Transportation Center Research Report

Data entry and operation of a generalized slope stability computer program are described. The computer program is based on a new approach to formulating and solving the slope stability equilibrium equations. The moment equation as well as the horizontal and vertical equilibrium equations are considered in the model. The purpose of the study was to implement the new approach. The computer program may be used to compute the factor of safety of slip surfaces of arbitrary shape and circular slip surfaces. Effective stress and total stress conditions may be analyzed. Four options are available for computing pore pressures. Both piezometric …

Traffic Accident Rates In Kentucky (1984), Kenneth R. Agent

Kentucky Transportation Center Research Report

Average accident rates, using 1984 accident data only as well as combined 1980 through 1984 data, were calculated for Kentucky highways. Comparison of 1984 to combined 1980 through 1983 rates show the rates have remained stable. There was an increase in total accidents and total accident rate in 1984 compared to 1980 through 1983 data while there was a decrease in the fatal accident rate. Several methods of classifying highways were used when calculating average rates. Those rates may be used in the high-accident location identification program. Average and critical numbers of accidents also were determined for use in the …

Workshop On Roadway And Street Drainage, Ronald D. Hughes, David L. Allen

Kentucky Transportation Center Research Report

No abstract provided.

The Feasibility Of Draglines For Mine Reclamation, Mark Anderson

Kentucky Transportation Center Research Report

Draglines are presented in this paper as an alternative for mine reclamation in steep sloping areas. Some abandoned mines in steep sloping areas of Kentucky have unreclaimed slopes which pose safety problems, as well as environmental and aesthetic problems. In addition, many active mines in steep sloping areas of Kentucky have slopes which must be reclaimed in the near future. Current methods of slope reclamation in Kentucky typically involve traditional heavy equipment. The current methods are not cost efficient in some cases, and are not safe in some applications.

The paper includes a history of draglines. Early development is summarized, …

Estimation Of Equivalent Axleloads, John A. Deacon, Jerry G. Pigman, Jesse G. Mayes

Kentucky Transportation Center Research Report

The primary objective of this research study was to develop a procedure for estimating equivalent axle loads for purposes of flexible-pavement design. Maximum use was made of historical data and well-accepted procedures were used in developing the prediction model. A series of computer programs was developed to summarize truck-weight and classification data such that traffic characteristics could be estimated from a matrix of data classified by geographic area, Federal highway system, volume, and extent of coal haulage. An equation was developed with the following seven parameters as independent variables; 1) annual average daily traffic volume, 2) average fraction of trucks …

A Computerized Analysis Of Flexible Pavement Rutting Behavior (Pavrut), David L. Allen, Robert C. Deen

Kentucky Transportation Center Research Report

The behavior of asphalt-bound layers, unbound aggregate bases, and foundation soils (subgrades) may be affected by such variables as gradation, asphalt and (or) moisture contents, type of aggregate, density, method of compaction, temperature, magnitude and frequency of loading, duration of each load cycle, and other less significant variables. The complex interaction of all these variables yields a composite behavior for a particular pavement structure that could become manifest in some form of distress or even complete "failure."

Flexible pavements are susceptible to rutting. But it is not well known where and to what extent rutting takes place within a pavement …

Evaluation Of Stone Column Stabilized Embankment Foundation, Bobby W. Meade, David L. Allen

Kentucky Transportation Center Research Report

The purpose of this study was to document construction procedures, monitor field performance, and make recommendations concerning the effectiveness and future use of a foundation improvement procedure using stone columns for stabilization. This effort was executed by use of field inspections and photographs, instrumentation to monitor foundation and field responses and laboratory analyses of existing and possible conditions.

Instrumentation included earth pressure meters, a multipoint settlement gage, a horizontal slope inclinometer, a settlement platform and vertical slope inclinometers. Settlement of the foundation after column construction was found to be approximately 8 inches as compared to a predicted total settlement of …

Jefferson Freeway Investigation (Westbound Lanes), Herbert F. Southgate, Gary W. Sharpe, Theodore Hopwood Ii, James H. Havens, Mark Anderson, David Q. Hunsucker, Robert C. Deen

Kentucky Transportation Center Research Report

The Kentucky Transportation Research Program (KTRP) was retained to perform an investigation for the Kentucky Department of Highways to assess damage that may be attributed to passage of the Model 992C over portions of the Jefferson Freeway. KTRP investigators conducted visual surveys, performed Road Rater deflection tests, did in-place California Bearing Ratio (CBR) testing on subgrade materials, obtained pavement cores, and conducted laboratory tests and analyses.

It appeared the pavement was damaged by the front-end loader. No evidence of damage to the bridges attributable to the front-end loader was detected. Damage to the pavement attributable to passage of the front-end …

Suggested Changes To Kentucky Statutes (Vehicle Weights And Dimensions), Herbert F. Southgate, Robert C. Deen

Kentucky Transportation Center Research Report

The purposes of this report are: 1. To clearly define the terms ''tandem," "tridem," and “triaxle." 2. To clearly define the term "600 pounds per inch width of tire" as the "width of the tread in contact with the pavement." 3. To make the axle load limits the same throughout the statutes. 4. To suggest elimination of indentified discriminatory legislation. 5. To recommend additional legislation: a. to clearly define the purpose and use of "air-bag" suspension systems -- those that can be raised or lowered by the driver, and b. to enable vehicle weight enforcement officers to use shipping documents …

Impact Evaluation Of The Traffic Alcohol Program In Lexington, Kentucky, Jerry G. Pigman, Kenneth R. Agent

Kentucky Transportation Center Research Report

This report is an evaluation of increased police enforcement to reduce alcohol-related accidents in Lexington-Fayette County, Kentucky. Three types of data were coIlected as a means of evaluating the Traffic Alcohol Program; accident data, arrest and adjudication data, and cost-effectiveness data.

Results from before-and-after comparisons and time-series analysis show alcohol related accidents decreased significantly during the study period. When comparing two years before with three years during the increased enforcement, the percent reduction in alcohol-related accidents was 28.1 percent using standard before and after analysis and 29.1 percent using time-series analysis. During the same time period, alcohol related fatal or …

A Survey Of The States On Problems Related To Bridge Approaches, David L. Allen

Kentucky Transportation Center Research Report

A questionnaire was sent to the states concerning problems with bridge approaches. Seven questions were included in the survey, including questions on the use of integral end bents and spread footers. This report summarizes the responses. Appendix A contains the detailed responses received, and Appendix B contains specifications and standard drawings used by some of the states.

Traffic Trends And Their Relationship To Highway-Use Revenues, Jerry G. Pigman, Manouchehr Vaziri

Kentucky Transportation Center Research Report

With increasing concerns about the present level of highway funding, this study was initiated to investigate historical trends and to develop predictive methodologies for considering alternatives available for increasing highway revenues. Emphasis was placed on historical trends, and a data base of highway-related and socio-economic variables were prepared to document the relationship between these variables and highway-user revenues. A historical file of 37 variables was prepared for the period 1964 through 1984.

As a means of investigating future alternatives that will affect highway-user revenues, a series of nine equations or models were developed that represented historical data. Input data necessary …

Latex-Concrete Overlays On Bridge Decks (I64, Mp 150 To West Virginia Line), James H. Havens, Theodore Hopwood Ii

Kentucky Transportation Center Research Report

Visual field inspections and soundings were performed on latex concrete overlays on 24 bridges on I 64 between Milepoint 150 and the West Virginia state line. The inspections were conducted in response to a request from the Kentucky Department of Highways to determine if cracking problems in the overlays were related to workmanship or materials.

The field inspections revealed that most of the overlay crack problems were related to 1) reflection cracking caused by pre-existing fractures in underlying concrete bridge decks and 2) “pull-in” cracks in the overlay, caused by belated tyning of the bridge deck.

Field diaries, inspection reports, …

1985 Safety Belt And Child Safety Seat Usage Rates In Kentucky And Evaluation Of A Public Information Campaign, Kenneth R. Agent

Kentucky Transportation Center Research Report

Two objectives of the survey are summarized in this report. One was to establish 1985 safety belt and child safety seat usage rates in Kentucky and compare those to 1982, 1983, and 1984 rates. The other was to evaluate the effectiveness of public information campaigns as a means of increasing safety belt and safety seat usage rates.

Statewide usage rates in the 19 cities previously surveyed in 1982, 1983, and 1984 indicated that driver safety belt usage had increased to 9.2 percent in 1985 while the child safety seat and belt usage rate of 29.1 percent remained at the 1984 …

Demonstration And Preliminary Evaluation Of The Acoustic Emission Weld Monitor, Theodore Hopwood Ii, Robert C. Deen

Kentucky Transportation Center Research Report

This report describes the demonstration and preliminary evaluation of the microprocessor-based acoustic emission weld monitor (AEWM) developed for the Federal Highway Administration by GARD Inc. of Niles, IL. The equipment was tested successfully on butt welds in several fabrication shops by the Kentucky Transportation Research Program (KTRP). Some problems were encountered in monitoring fillet welds.

The AEWM was demonstrated to personnel from 20 state agencies representing FHWA Regions 1, 3, 4, and 5. The demonstrations were performed at three different fabrication shops in Pennsylvania, Georgia, and Wisconsin.

A preliminary evaluation of the AEWM is included. Also, the summary of a …

Evaluation Of Construction Zone Pavement Marking Materials, Kenneth R. Agent, Jerry G. Pigman

Kentucky Transportation Center Research Report

The objectives of this report were to evaluate all available foil-back and removable tapes as well as construction zone raised pavement markers and to recommend materials that should be included on approved lists for use by the Kentucky Department of Highways. The tapes were placed on transverse test sections and as lane lines and the reflectivity, durability, and appearance were observed. The markers were observed at test sections as well as at construction sites.

Lists of tapes to be included on the approved lists for foil-back and removable tapes were recommended. Tapes manufactured by 3M and Flex-0-Lite were included on …

Guidelines For The Use Of Protected/Permissive Left-Turn Phasing, Kenneth R. Agent

Kentucky Transportation Center Research Report

The objective of this study was to develop guidelines that may be used to aid the traffic engineer in deciding whether protected/permissive (permissive) phasing is appropriate to use at a given location. An inventory identified 58 intersections in Kentucky where permissive phasing was used. Characteristics of these intersections were related to accident data to determine the effect permissive phasing has had on p.eft-turn and total accidents.

Left-turn accidents increased dramatically when permissive phasing replaced protected-only (exclusive) phasing and when it was used at approaches where the speed limit was over 45 mph. There were no substantial changes in left-turn and …

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

Kentucky Transportation Center Research Report

An annual highway safety program is proposed each year for the State of Kentucky in order to comply with Section 402, Title 23 of the United States Code. This program includes the identification, programming, budgeting, and evaluation of safety projects. This report is the sixth in a series of annual reports which have been prepared as the problem identification portion of Kentucky's Annual Highway Safety Plan.

In the past, the approach to problem identification has been to identify problem areas in the 18 highway safety program areas (standards). While the search for problems in each of these standard areas will …

Sampling Techniques For The Collection Of Vehicle Classification Data, Jerry G. Pigman

Kentucky Transportation Center Research Report

The question of what length of time is necessary to collect statistically reliable vehicle classification data is an important issue when manpower is limited. Varying local conditions may necessitate more classification data be collected at some locations than others. The use of short-term counts could produce significant savings. Supplementing manual counts with automatic classification equipment could reduce data collection costs and improve accuracy.

The objectives of this study were to review literature to determine the capabilities of automatic classification equipment and to analyze toll road data in Kentucky to determine if short time periods may be used to represent the …

Effects Of Load Distributions And Axle And Tire Configurations On Pavement Fatigue, Herbert F. Southgate, Robert C. Deen

Kentucky Transportation Center Research Report

Damage factor relationships for axle and tire configurations are presented. Adjustment factors are provided to account for variations in load distributions within axle groups, distances between axles of a tandem, and variations in tire pressure for both dual and flotation tire configurations.

Properly accounting for accumulated fatigue of a pavement requires an accurate Measure of traffic volume, proportions of vehicle styles (classifications) within the traffic stream, dates of service, estimate of the average damage factor for each classification, and estimate of the tire contact pressure. Weigh-in-motion equipment in its current form provides all of the above ingredients except for the …

Effectiveness Of Traffic Noise Barrier On I 471 In Campbell County, Kentucky, Tom Creasey, Kenneth R. Agent

Kentucky Transportation Center Research Report

The objective of this study was to evaluate the effectiveness of the traffic noise barrier on I 471 in Campbell County, Kentucky. Since the barrier coincided with construction of I 471, it was necessary to predict noise levels that would exist if no barrier were present utilizing the FHWA STAMINA 2.0 computer model. This was compared to actual noise level measurements at the barrier site to determine the barrier insertion loss.

After calibration of the STAMINA 2.0 model, noise measurements were conducted at 39 receiver locations during off-peak and peak traffic conditions. The noise barrier reduced the noise level reaching …

Feasibility Of Computerization Of The Bid Item Section Of Bid Proposals, Jesse G. Mayes, Mark Isenhour

Kentucky Transportation Center Research Report

The feasibility of computerizing the bid item listing in bid proposals has been studied. As a result, a system of computer programsfor the IBM PC microcomputer has been written and submitted to the Division of Contract Procurement, Kentucky Department of Highways, for implementation. This software is menu driven and provides the capability of building and maintaining a bid item code file and interactively building a bid sheet file for producing blank bid sheets as well as a bid estimate. Additionally, a restricted version of this program has been provided to allow the contractor to produce a computerized bid proposal.

Summary Report Of Ranking Methodologies, Robert C. Deen

Kentucky Transportation Center Research Report

Participants in the ranking methodologies workshops were a good representation of those various actors (types of agencies or organizations) in the pavement management process. There were nineteen participants, nine of whom were from the United States, six from Canada, and four from European countries. Of the nineteen, eight represented state or provincial governmental units, three represented municipalities, four were employees of national highway agencies, and another four were either consultants or representatives of universities. Unfortunately, however, all participants represented the technical levels involved in pavement ranking. No one was present to provide the viewpoint of the ultimate decision makers -- …

Long-Term Movements Of Highway Bridge Approach Embankments And Pavements, Tommy C. Hopkins

Kentucky Transportation Center Research Report

Long-term movements of highway bridge approach embankments and pavements are described and factors that may lead to settlement of highway bridge approach pavements are discussed. Six case histories are presented. The bridge approach sites were observed at different times during the period 1966 to 1985. At four sites, lateral movements, measured from slope inclinometers, of the approach embankments were monitored over time periods ranging from 8 to 14 years. Settlements of the highway bridge approaches were monitored some three to four years after paving. Estimated and observed settlements of the foundations at the study sites were obtained for a length …

Analysis Of Movements And Forces On Bridge Approaches: A Case Study (Bridge Over Chesapeake Ave. On Interstate 471 In Campbell County, Kentucky), David L. Allen, Bobby W. Meade, Tommy C. Hopkins

Kentucky Transportation Center Research Report

A case study is presented of a bridge on Interstate 471 in Campbell County, Kentucky. The south approach to the bridge is a side-hill fill. During construction, the south intermediate piers tilted as a result of movement in the south approach foundation. Construction was temporarily halted on the south approach embankment, allowing pore pressures in the foundation to dissipate and slowing the movement. The piers were than reconstructed.

The south approach end bents were instrumented with earth pressure meters. The piles were instrumented with slope inclinometers. Most recent data show that movement is continuing and the present factor of safety …

Fly Ash Stabilized Bases In Kentucky, Gary W. Sharpe, Larry Epley

Kentucky Transportation Center Research Report

With the escalating costs of materials and construction for highways and streets, many agencies charged with the responsibility of designing and constructing highways are utilizing byproduct stabilized (pozzolanic) materials. Low-strength (pozzolanic) materials have been used fairly extensively in some areas of the United States as well as abroad. In general, pozzolanic materials have been used to stabilize an aggregate base or subbase by addition of fly ash and a source of lime to develop a cementitious reaction. Additionally, portland cement or cement kiln dust have been used to stabilize aggregate subbase and (or) base materials.

Until recently, the use of …