<?xml version="1.0" encoding="utf-8"?><rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>TRB Publications Index</title><link>http://pubsindex.trb.org/</link><atom:link href="http://pubsindex.trb.org/common/TRIS Suite/feeds/rss.aspx?tc=NN%3AHbxbb%2A" rel="self" type="application/rss+xml" /><description></description><language>en-us</language><copyright>Copyright © 2015. National Academy of Sciences. All rights reserved.</copyright><docs>http://blogs.law.harvard.edu/tech/rss</docs><managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor><webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster><image><title>TRB Publications Index</title><url>http://pubsindex.trb.org/Images/PageHeader-wTitle.png</url><link>http://pubsindex.trb.org/</link></image><item><title>PERFORMANCE OF STUDDED TIRES ON ICE</title><link>http://pubsindex.trb.org/view/104794</link><description><![CDATA[AN INCREASE IN BOTH TRACTION AND SKID RESISTANCE WAS INDICATED BY THE RESULTS OF TESTS OF STUDDED TIRES ON ICE IN 1964 AND 1965 BY THE NATIONAL SAFETY COUNCIL COMMITTEE ON WINTER DRIVING HAZARDS. HOWEVER, SINCE A NUMBER OF QUESTIONS WERE STILL LEFT UNANSWERED, IT WAS DECIDED TO WAIT UNTIL JANUARY 1967 BEFORE MAKING A FULL REPORT. AT THAT TIME, THE 1966 TEST INFORMATION COULD ALSO BE INCLUDED.]]></description><pubDate>Mon, 07 Nov 1994 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/104794</guid></item><item><title>DISTRESS MEASUREMENT AND INTERACTION OF VEHICLES WITH PAVEMENT SURFACES</title><link>http://pubsindex.trb.org/view/196371</link><description><![CDATA[This Record contains the following papers: Visual Scales of Pavement Condition: Development, Validation, and Use, D. J. Hartgen et al; Roughness Computer Program for Engineers and Management, K. J. Cheng et al; Suggested Improved Methodology for Relating Objective Profile Measurement with Subjective User Evaluation, L. R. Lenke; Road Profile Evaluation for Compatible Pavement Evaluation (Abridgment), D. W. McKenzie and W. R. Hudson; Inertial Profilometer Uses in the Pavement Management Process, E. B. Spangler; Prediction and Significance of Wet Skid Resistance of Pavement Marking Materials, D. A. Anderson et al; Tire Testing at Low Speed on an Ice Rink, G. F. Hayhoe and J. J. Henry; Determination of Precrash Parameters from Skid Mark Analysis, W. R. Garrott and D. A. Guenther; Methodology for Analyzing Texture and Skid Resistance Data for Use in Pavement Management Systems, E. C. Yeh et al; Ontario Flexible Pavement Distress Assessment for Use in Pavement Management, W. A. Phang and G. J. Chong; Airfield Pavement Distress Measurement and Use in Pavement Management, M. Y. Shahin.]]></description><pubDate>Wed, 30 Nov 1983 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/196371</guid></item><item><title>DETERMINATION OF PRECRASH PARAMETERS FROM SKID MARK ANALYSIS</title><link>http://pubsindex.trb.org/view/189122</link><description><![CDATA[This paper presents the results of an experimental study to validate and improve the methods currently used in the reconstruction of accidents to determine precrash parameters from skid marks.  This was accomplished by testing six vehicles, three cars and three trucks, that had a variety of tires and loadings on three differing types of pavements.  Both severe (wheels locked) and moderate (no wheels locked) stops were made.  Prebraking speed, the length of the skid marks produced, stopping distance, and a number of other variables of interest were measured for each stop.  Analysis of the experimental data focused on repeatability of skid mark data, validity of the currently used skid mark length versus prebraking speed formula, accuracy of the various methods for measuring tire friction, and tire marks left by nonlocked wheels.  The currently used skid mark length versus prebraking speed formula was found to be better for accident reconstruction when using test data from locked wheel stops than were either of two other formulas that were tried.  Four methods for measuring tire friction were evaluated.  Two of these methods, the American Society for Testing and Materials skid number and an estimate based on a standard table found in the literature, were shown to give incorrect results when used for heavy, air-braked trucks.  For some conditions, stops for which none of the vehicle's wheels locked were found to produce tire marks that were longer than those produced during a locked wheel stop.  The tire marks generated during nonlocked wheel stops look like light shadowy (visible when viewed along their length but not from directly above) skid marks.  Accident investigators must be careful when using light skid marks in the formulas to determine prebraking speed from skid mark length to ensure that the skid marks were made by locked wheels. Otherwise, too high an estimate of the vehicle's prebraking speed may be obtained.  (Author)]]></description><pubDate>Tue, 31 May 1983 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/189122</guid></item><item><title>FRICTION AND THE MECHANICS OF SKIDDING AUTOMOBILES</title><link>http://pubsindex.trb.org/view/116525</link><description><![CDATA[THIS PAPER DEMONSTRATES THAT A RATHER GENERAL MATHEMATICAL MODEL OF A SKIDDING AUTOMOBILE CAN BE CONSTRUCTED AND SOLVED WITH LITTLE DIFFICULTY. THE SOLUTION CAN BE USED IN CURVE-FITTING OF DATA FROM STOPPING DISTANCE EXPERIMENTS AND IN OBTAINING SPEEDS WHERE SKID DISTANCE AND FRICTION CHARACTERISTICS ARE KNOWN. SKID MARKS FROM ACCIDENT STUDIES ARE USED AS AN EXAMPLE. THE IMPORTANCE OF DRAG FORCES IS DISCUSSED, AND A WAY OF OBTAINING INSTANTANEOUS FRICTION COEFFICIENT MEASUREMENTS FROM STOPPING DISTANCES IS GIVEN. IT IS SUGGESTED THAT THE SUBSTITUTION OF INSTANTANEOUS FRICTION COEFFICIENT MEASUREMENTS, OBTAINED FROM SKID TRAILER RUNS, INTO STOPPING DISTANCES FORMULAS IS RESPONSIBLE FOR THE CALCULATED DISTANCE EXCEEDING ACTUAL MEASUREMENTS 90% OF THE TIME.]]></description><pubDate>Mon, 05 Jun 1972 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/116525</guid></item><item><title>SKID RESISTANCE MEASUREMENTS OF VIRGINIA PAVEMENTS, WITH DISCUSSION AND CLOSURE</title><link>http://pubsindex.trb.org/view/105232</link><description><![CDATA[MORE THAN 1000 MEASUREMENTS OF FORWARD SKIDDING DISTANCES ON 32 PAVEMENT SURFACES BOTH IN A DRY AND IN A WET CONDITION ARE REPORTED. THE PURPOSE OF THE STUDY WAS TO OBTAIN DATA ON SURFACE CHARACTERISTICS THAT COULD BE USED AS A GUIDE FOR ESTABLISHING FUTURE DESIGN, CONSTRUCTION, AND MAINTENANCE POLICIES. BOTH GOOD AND WORN TREAD SYNTHETIC AND NATURAL RUBBER TIRES WERE EMPLOYED. SKID RESISTANCE MEASUREMENTS WERE MADE BY THE STOPPING DISTANCE METHOD. A LIGHT-WEIGHT AUTOMOBILE EQUIPPED WITH 6.00 BY 16 IN. 4-PLY TIRES WAS USED THROUGHOUT THE STUDY. THE TEST CAR WAS A FREE-MOVING VEHICLE AND NOT INFLUENCED BY THE SAME FORCES AS A TOWED VEHICLE. TESTS WERE CONDUCTED PRINCIPALLY ON HIGH-TYPE PAVEMENTS ON PRIMARY ROADS, INCLUDING BITUMINOUS CONCRETE, SAND ASPHALT, SPECIAL PLANT-MIX, ROCK ASPHALT, SAND AND SLAG SEAL TREATMENTS, BROOM DRAG TREATMENT, PORTLAND CEMENT CONCRETE, AND GLAZED BITUMINOUS SURFACES. TEST SECTIONS WERE SELECTED TO PERMIT AN EVALUATION OF DIFFERENT KINDS OF MATERIALS AND METHODS OF FINISHING. FORWARD SKIDDING DISTANCES INCREASED WITH SPEED AND WERE MUCH LONGER ON WET THAN ON DRY SURFACES. AT 40 MPH, MEASUREMENTS RANGED FROM 63.6 TO 88.9 FT. ON DRY AND 72.0 TO 254.5 FT. ON WET SURFACES. THE DATA INDICATED THAT AT THIS MAXIMUM SPEED (40 MPH) FORWARD STOPPING DISTANCES ARE CRITICAL ONLY ON THE WET PAVEMENTS. IT WAS CONSIDERED UNSAFE TO CONDUCT TESTS ON A WET SURFACE AT GREATER SPEEDS. TWENTY-SEVEN OF THE 32 SURFACES WERE FOUND TO HAVE SATISFACTORY NON-SKID CHARACTERISTICS IN A WET CONDITION. THOSE SURFACES HAVING A ROUGH TEXTURE WERE FOUND TO HAVE SHORT STOPPING DISTANCES AND CORRESPONDINGLY HIGH COEFFICIENTS OF FRICTION. NON-SKID TREATMENTS WERE EFFECTIVE IN REDUCING FORWARD SKIDDING DISTANCES ON WET SURFACES. THE STOPPING DISTANCE METHOD WAS FOUND TO BE A RELATIVELY SIMPLE, INEXPENSIVE, QUICK MEANS OF MEASURING SKID RESISTANCE OF PAVEMENT SURFACES. CLOSE CHECK RESULTS WERE OBTAINED. /AUTHOR/]]></description><pubDate>Mon, 22 May 1972 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/105232</guid></item><item><title>LABORATORY APPARATUS FOR FRICTION TESTS BETWEEN TIRES AND PAVEMENTS</title><link>http://pubsindex.trb.org/view/105083</link><description><![CDATA[A MACHINE HAS BEEN BUILT TO MEASURE IN THE LABORATORY THE FOLLOWING CHARACTERISTICS OF IRON PAVING BLOCKS: (1) THE COEFFICIENT OF FRICTION BETWEEN THE PAVING BLOCKS AND RUBBER TIRES FOR STRAIGHT SKIDDING AND FOR SIDEWAYS SKIDDING, (2) THE STOPPING DISTANCE OF A CAR ON SUCH A PAVEMENT, AND (3) THE TIRE NOISE. THE MACHINE CONSISTS OF TWO SIX-FOOT FLYWHEELS, ON THE PERIPHERY OF WHICH ARE BOLTED THE PAVING PLATES TO BE TESTED. AN AUTOMOBILE IS MOUNTED SUCH THAT ITS FRONT WHEELS REST ON THESE FLYWHEELS. THE FLYWHEELS ARE ROTATED BY A 15 HORSEPOWER MOTOR TO TOP PERIPHERAL SPEEDS OF 60 MILES PER HOUR. HYDRAULIC TRACTION DYNAMOMETERS ARE CONNECTED TO THE CENTER OF GRAVITY OF THE CAR AND SERVE TO MEASURE THE BRAKING FORCE AND THE SIDEWAYS FORCE WHEN THE BRAKES ARE APPLIED OR WHEN THE FRONT CAR WHEELS ARE TURNED THROUGH AN ANGLE. A HIGH-SPEED MOTION PICTURE CAMERA IS USED TO RECORD THE DYNAMOMETER READINGS, THE TIME, AND THE MOTION OF THE FLYWHEELS AND OF THE FRONT CAR WHEELS. EXAMPLES OF THE CURVES SO OBTAINED ARE GIVEN. IT HAS BEEN FOUND THAT BY CHANGING THE DESIGN OF THE SURFACE PAVEMENT CORRUGATIONS, THE COEFFICIENT OF FRICTION MAY BE CHANGED BY MORE THAN 100 PER CENT. /AUTHOR/]]></description><pubDate>Sun, 15 Aug 1971 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/105083</guid></item></channel></rss>