Highway Research Record 

About: Highway Research Record is an academic journal. The journal publishes majorly in the area(s): Transportation planning & Population. Over the lifetime, 2473 publications have been published receiving 22491 citations.

Management of research. introduction

Abstract: The purpose and functions of the Highway Research Board's Committee on Conduct of Research are set forth, and papers sponsored by the Committee and presented at the Annual Meetings of the Highway Research Board are mentioned. The Committee, which seeks to improve the quality and effectiveness of research, serves as a forum for the exhange of ideas and the delineation of the problems associated with the various methods of organizing and administering research programs, the consideration of project design and instrumentation, and the application of research findings in the transportation field. The Committee has sponsored Annual Meeting sessions (in 1969, 1973, and 1974) on various aspects (selection, design, and supervision of projects as well as the implementation of results and evaluation of the benefits) of research management. Papers presented at the 1969 sessions were published in Highway Research Record 338. Eight papers presented at the 1973 sessions are included in this publication.

Near-miss determination through use of a scale of danger

Abstract: NEAR-MISS TRAFFIC EVENTS HAVE BEEN CONSIDERED BUT NOT ADOPTED AS A TRAFFIC SAFETY TOOL BECAUSE OF THE HIGH DEGREE OF SUBJECTIVITY INVOLED WITH THEIR IDENTIFICATION. A SCALE OF DANGER MAY BE APPLIED TO A TRAFFIC EVENT TO FACILITATE OBJECTIVE MEASUREMENT AND SUBSEQUENT DETECTION OF NEAR-MISS SITUATIONS. THE UNIT PROPOSED HERE FOR THIS DANGER SCALE IS THE TIME MEASURED UNTIL COLLISION BETWEEN TWO VEHICLES INVOLVED IN THE UNSAFE EVENT. THIS MEASURE, COMPUTED FROM FILMS TAKEN WITH THE TRAFFIC SENSING AND SURVEILLANCE SYSTEM OF THE FEDERAL HIGHWAY ADMINISTRATION AT AN URBAN INTERSECTION, IS AN ADEQUATE UNIT TO RATE THE DANGER OF ALMOST ANY TRAFFIC EVENT. IT MAY BE USED TO STANDARDIZE HUMAN OBSERVER JUDGEMENT OF DANGEROUS MANEUVERS AND, THEREFORE, MAKE NEAR-MISS MONITORING A VIABLE ALTERNATIVE TO TRAFFIC SAFETY DETERMINATION. /AUTHOR/

Designing for pedestrians: a level-of-service concept

Abstract: PEDESTRIAN FACILITIES SHOULD BE DESIGNED ON THE BASIS OF QUALITATIVE AS WELL AS QUANTITATIVE FACTORS. PRESENT PROCEDURES INVOLVE THE USE OF MAXIMUM CAPACITY RATINGS FOR DESIGN. THE CAPACITY OF A PEDESTRIAN TRAFFIC STREAM INVARIABLY OCCURS AT THE HEAVIEST CONCENTRATIONS COMBINED WITH RESTRICTED WALKING SPEEDS. THIS CONDITION IS NOT REPRESENTATIVE OF A COMFORTABLE HUMAN ENVIRONMENT. TIME-LAPSE PHOTOGRAPHY STUDIES MAKE IT POSSIBLE TO ESTABLISH THE RELATIONSHIP BETWEEN VOLUME, SPEED, AND HUMAN CONVENIENCE AT DIFFERENT PEDESTRIAN CONCENTRATIONS. THE STUDIES FORM THE BASIS FOR SIX LEVELS OF SERVICE FOR THE DESIGN OF WALKWAYS AND STAIRWAYS. THESE LEVELS OF SERVICE PROVIDE A QUALITATIVE METHOD OF DESIGNING NEW OR EVALUATING EXISTING PEDESTRIAN ENVIRONMENTS. /AUTHOR/

Factors influencing the resilient response of granular materials

Abstract: THE PURPOSE IS TO DEFINE BETTER THOSE PROPERTIES OF GRANULAR BASE MATERIALS THAT CONTRIBUTE TO THE RESILIENT RESPONSE OF PAVEMENT STRUCTURES. A STUDY IS INCLUDED OF THE INFLUENCE OF AGGREGATE DENSITY, AGGREGATE GRADATION (PERCENT PASSING NO. 200 SIEVE), AND DEGREE OF SATURATION ON THE RESILIENT RESPONSE OF TWO AGGREGATES REPRESENTATIVE OF THOSE USED IN THE CONSTRUCTION OF ASPHALT CONCRETE PAVEMENTS. TESTS CARRIED OUT IN TRIAXIAL COMPRESSION, CONSISTED OF APPLYING REPEATED AXIAL STRESSES WITH REALISTIC STRESS HISTORIES AT A FIXED FREQUENCY AND AT A LOAD DURATION REPRESENTATIVE OF THAT EXPECTED IN THE FIELD. FOR BOTH GRANULAR MATERIALS, THE RESILIENT MODULUS INCREASED CONSIDERABLY WITH AN INCREASE IN CONFINING PRESSURE AND ONLY SLIGHTLY WITH AN INCREASE IN AXIAL STRESS. POISSON'S RATIO INCREASED WITH A DECREASE IN CONFINING PRESSURE AND AN INCREASE IN REPEATED STRESS. THE RESILIENT MODULUS AND POISSON'S RATIO WERE ALSO AFFECTED TO LESSER DEGREES BY DENSITY, PERCENT PASSING THE NO. 200 SIEVE, AND DEGREE OF SATURATION. AN ANALYSIS OF A CONVENTIONAL ASPHALT CONCRETE PAVEMENT OVER A SANDY CLAY SUBGRADE INDICATED THAT REASONABLE CHANGES IN THE MODULUS OR POISSON'S RATIO OF THE GRANULAR BASE LAYER CAN RESULT IN CONSIDERABLE CHANGES IN THE RESPONSE OF THE PAVEMENT STRUCTURE TO LOAD. /AUTHOR/

A quick test to determine lime requirements for lime stabilization

Abstract: THE USE OF HYDRATED LIME, CA/OH/2, FOR MODIFYING, UPGRADING, AND STABILIZING SOILS IS INCREASING GREATLY. THIS MEANS HIGHWAY LABORATORIES HAVE HAD THEIR WORK LOADS INCREASED, AND IN MANY INSTANCES, MORE THAN DOUBLED FOR A PARTICULAR JOB. BEFORE THE ADVENT OF THE USE OF LIME, THE LABORATORY WAS FINISHED WITH TESTING WHEN A SOIL WAS CLASSIFIED AS UNSUITABLE. NOW THE SAME SOIL IS TESTED AND RETESTED TO FIND THE PERCENTAGE OF LIME REQUIRED TO BRING THE SOIL WITHIN SPECIFICATIONS. IN MOST CASES THE PERCENTAGE IS DETERMINED BY COMPRESSIVE TESTS, ATTERBERG LIMITS TESTS, OR BOTH. THE REACTION OF LIME AND SOIL CAN BE DESCRIBED AS A SERIES OF CHEMICAL REACTIONS. THE RESULTS OF THESE REACTIONS ARE EXPRESSED AS A CHANGE IN THE PLASTICITY, SWELL, SHRINKAGE OR COMPRESSIVE STRENGTH OF THE SOIL. THEREFORE, A QUICK OR SIMPLE TEST IS NEEDED TO SHOW THE AMOUNT OF LIME REQUIRED TO REACT CHEMICALLY WITH A SOIL TO BRING ABOUT THESE PHYSICAL CHANGES TO AN OPTIMUM DEGREE. LABORATORY TESTS, INVOLVING MINERALOGICAL, PHYSICAL AND CHEMICAL CHARACTERISTICS OF UNTREATED AND LIME-TREATED SOILS HAVE PROVEN THAT PH TESTS CAN BE USED TO DETERMINE THE OPTIMUM LIME REQUIREMENTS OF A SOIL. /AUTHOR/