<?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%3ASmdffdc%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>Alternative Stream Channel Maintenance at Bridges in Ohio: Outcomes of a Participatory Research Project</title><link>http://pubsindex.trb.org/view/1496575</link><description><![CDATA[The Ohio Department of Transportation (ODOT) maintains &gt;44,000 bridges statewide.  Annually, hundreds of maintenance projects are undertaken by county maintenance crews to mitigate the effects of stream channel scour and sediment aggradation that impacts the structural integrity and conveyance capacity of many bridges. Current maintenance practices have limitations and often provide only temporary resolution to the maintenance issue.  As a result, ODOT sought out research to identify alternative maintenance practices that are: 1) more sustainable (i.e. reduce long-term maintenance frequency), 2) environmentally sensitive, 3) economical, and 4) readily implementable by county maintenance crews.  Reconnaissance was conducted to identify representative sites with typical maintenance problems to serve as case study examples.  Based on literature review and experience of the research team, a range of alternative maintenance practices were identified.  Potential solutions were further refined as researchers worked with ODOT staff to inventory equipment available for construction, identify construction materials that could be obtained with reasonable effort, and assess skills sets of ODOT maintenance crews.  Proposed maintenance projects were presented to ODOT staff and subsequently revised during multiple iterations of a participatory design process.  Flow altering devices (e.g. vanes, w-weirs, etc.) commonly used in the field of stream restoration and “softer” bank stabilization materials were selected for further investigation.  The following paper describes typical maintenance problems at bridge crossings, outlines historical maintenance practices in Ohio, provides information on alternative practices implemented through the research effort, and provides details on a pilot project that was implemented by county maintenance crews.]]></description><pubDate>Fri, 16 Mar 2018 09:51:10 GMT</pubDate><guid>http://pubsindex.trb.org/view/1496575</guid></item><item><title>LOAD LIMITATIONS ON HIGHWAYS</title><link>http://pubsindex.trb.org/view/116799</link><description><![CDATA[IN ORDER TO PROTECT THE PRESENT HIGHWAYS AND TO AVOID THE NECESSITY OF DESIGNING FUTURE HIGHWAYS FOR UNREASONABLY HEAVY LOADS, LEGAL LIMITATIONS ON LOADS HAVE BEEN IMPOSED BY ALL STATES. THE STATES HAVE GENERALLY ACTED INDEPENDENTLY IN THE MATTER SO THAT A GREAT VARIETY OF RESTRICTIONS EXISTS WHICH OFTEN IMPOSE HANDICAPS ON TRUCK TRAFFIC WITHOUT ACHIEVING THEIR AIM OF PROTECTING THE HIGHWAYS. IT HAS BEEN SHOWN BY TESTS THAT TRUCK WHEELS MAY BE PLACED IN TANDEM AT THE MINIMUM PRACTICAL SPACING WITHOUT PRODUCING GREATER STRESSES IN PAVEMENTS THAN ARE PRODUCED BY A SINGLE WHEEL CARRYING A LOAD EQUAL TO THAT ON EACH WHEEL, IN TANDEM. IT IS, THEREFORE, NECESSARY TO LIMIT ONLY THE WHEEL LOAD TO ADEQUATELY PROTECT PAVEMENTS. BRIDGES ARE DESIGNED FOR CONCENTRATED LOADS ON SHORT SPANS AND A UNIFORM LOAD OR A COMBINATION OF UNIFORM AND CONCENTRATED LOADS FOR LONGER SPANS. IT IS OBVIOUSLY DESIRABLE TO SPECIFY LOAD RESTRICTIONS OF A FORM SIMILAR TO THE DESIGN LOAD SO THAT IT WILL BE APPLICABLE TO ANY TYPE OF TRUCK TRAIN AND ANY SPAN LENGTH AVOIDING THE NECESSITY, AS FAR AS POSSIBLE, OF MAKING PROVISION FOR SPECIAL CASES. SUCH A FORM OF LIMITATION COULD THEN BE MADE APPLICABLE TO BRIDGES DESIGNED FOR ANY LOAD BY VARYING THE CONSTANTS CONTROLLING THE INTENSITY OF LOAD. LOAD LIMITATIONS BASED ON THE DESIGN LOADS OF THE AMERICAN ASSOCIATION OF STATE HIGHWAY OFFICIALS ARE PRESENTED AND A STUDY HAS BEEN MADE OF THE STRESSES WHICH ARE PRODUCED BY THE LOADINGS OF THE A.A.S.H.O. AND BUREAU OF PUBLIC ROADS OF 1919. /AUTHOR/]]></description><pubDate>Sun, 01 Jun 2003 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/116799</guid></item><item><title>THE DESIGN OF SUPERCRITICAL FLOW CHANNEL JUNCTIONS</title><link>http://pubsindex.trb.org/view/103833</link><description><![CDATA[THE PURPOSE OF THE PAPER IS TO DISCUSS THE DIAGONAL WAVE AND PILE-UP PROBLEMS WHICH RESULT FROM THE INTERSECTION OF TWO OPEN CHANNELS, EACH CARRYING WATER AT SUPERCRITICAL VELOCITIES. METHODS ARE SET FORTH FOR THE DETERMINATION OF THE HEIGHT OF WALL PILE-UP WHICH OCCURS UNDER CONDITIONS OF DESIGN FLOW AND UNDER THE UNBALANCED CONDITIONS OF FLOW IN ONLY ONE OF THE CHANNELS. FOR THE DETERMINATION OF PILE-UP HEIGHT FOR THESE CONDITIONS IT IS NECESSARY TO REFER TO LABORATORY CURVES WHICH ARE INCLUDED. A CHANNEL JUNCTION DESIGN IS SUGGESTED WHICH HAS MINIMIZED THE WAVE PROBLEM IN LABORATORY EXPERIMENTS. THE JUNCTION DIFFERS FROM THE SIMPLE CHANNEL JUNCTION IN TWO WAYS. THE MAIN CHANNEL IS WIDENED AT THE JUNCTION TO ACCOMMODATE THE INCREASED DISCHARGE CONTRIBUTED BY THE SIDE CHANNEL, AND A BAFFLE, WHICH IS ACTUALLY ONLY AN EXTENSION OF THE MAIN CHANNEL WALL, IS EXTENDED DOWNSTREAM IN FRONT OF THE SIDE CHANNEL. THIS BAFFLE IS RECOMMENDED TO BE TAPERED AT A SLOPE EQUAL TO THE GREATER OF THE FROUDE NUMBERS IN THE MAIN OR SIDE CHANNELS, DIVIDED BY 50. SMALLER RATES OF TAPER ARE ACCEPTABLE, BUT MORE PRONOUNCED TAPERS RESULT IN PILE-UP PROBLEMS ON THE CHANNEL SIDES. THIS TYPE OF JUNCTION RESULTS IN ALMOST NO WAVE PROBLEM UNDER DESIGN CONDITIONS OF FLOW IN BOTH CHANNELS AND IT RESULTS IN LOW PILE-UP DEPTHS FOR CONDITIONS OF FLOW ONLY IN ONE CHANNEL OR THE OTHER. /AUTHOR/]]></description><pubDate>Mon, 21 Nov 1994 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/103833</guid></item><item><title>RELOCATION OF PUBLIC UTILITIES 1956-1966</title><link>http://pubsindex.trb.org/view/90278</link><description><![CDATA[LIMITED AUTHORITY TO REIMBURSE UTILITIES FOR THE COST OF RELOCATION IS EFFECTIVE IN THIRTY-THREE STATES. WHILE THE CONSTITUTIONALITY OF THE REIMBURSEMENT LAWS ARE ACKNOWLEDGED , THE LAWS CONTAIN AMBIGUITIES ON THE ELEGIBILITY OF SOME COSTS. THE BUREAU OF PUBLIC ROADS HAS ESTABLISHED GUIDELINES ON THE BASIS OF WHICH FEDERAL REIMBURSEMENT MAY BE MADE. STATE PRACTICES OF REPAYMENT UNDER PARTICULAR CIRCUMSTANCES ARE DISCUSSED. THESE INCLUDE THE PUBLIC AND PRIVATE PROPERTY RIGHTS OF UTILITIES, THE LEGALITY OF REIMBURSEMENT WHEN A UTILITY IS MOVED FROM THE HIGHWAY RIGHT-OF-WAY, AND REIMBURSEMENT RESTRICTIONS ON INCREASES IN VALUE DUE TO RELOCATION OR DEDUCTION OF SALVAGE. MEANS TO SECURE PROMPT RELOCATION AND THE AUTHORITY TO ACQUIRE NEW RIGHT-OF-WAY FOR UTILITIES ARE EXAMINED. ALTHOUGH THE QUESTION OF REIMBURSEMENT IS LEFT TO THE DISCRETION OF INDIVIDUAL STATES, CLARIFICATION OF STATE LEGISLATION IS URGED.]]></description><pubDate>Fri, 18 Nov 1994 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/90278</guid></item><item><title>PREDICTING THE ECONOMIC IMPACT OF ALTERNATE INTERSTATE ROUTE LOCATIONS</title><link>http://pubsindex.trb.org/view/93138</link><description><![CDATA[THE STUDY METHOD EMPLOYED IN A RECENT EXAMINATION OF THE COMPARATIVE ECONOMIC IMPACT OF THREE ALTERNATIVE ROUTES FOR AN INTERSTATE HIGHWAY IN THE VICINITY OF MAMMOTH CAVE, KY., APPEARS TO HAVE GENERAL SIGNIFICANCE FOR SUCH PLANNING INQUIRIES. THE CENTRAL PROBLEM IN THE INVESTIGATION WAS TO PREDICT THE QUANTITATIVE EFFECTS OF EACH ALTERNATIVE LOCATION ON HIGHWAY-ORIENTED BUSINESS SUCH AS IS NOW LOCATED ALONG A MAJOR NORTH-SOUTH ROUTE ROUGHLY PARALLEL TO THE PROJECTED ONE. TO FACILITATE THE PREDICTIONS, THE AUTHORS USE THE CONCEPT OF AN ECONOMICALLY NEUTRAL ROAD AS A STANDARD BY WHICH THE ALTERNATIVE LOCATIONS ARE JUDGED. THE EFFECTS ARE MEASURED IN TERMS OF BUSINESS VOLUME IN THE YEAR 1975. THE EXISTING MARKET BASE OF HIGHWAY-ORIENTED BUSINESSES IN THE AREA STUDIED IS DETERMINED AND A HYPOTHETICAL 1975 BUSINESS VOLUME IS PROJECTED. A SPECIALLY DESIGNED ORIGIN-AND-DESTINATION STUDY, A MOTEL SURVEY, A RESTAURANT SURVEY, NATIONAL PARK STATISTICS, AND GROSS RECEIPTS AND INCOME DATA ARE USED IN ESTABLISHING THE CURRENT VOLUME OF BUSINESS AMONG PARK VISITORS, THROUGH TRAVELERS ON THE HIGHWAY, AND LOCAL AREA RESIDENTS. AFTER ALLOCATING THE BUSINESS VOLUME OF MOTELS, RESTAURANTS, AND GASOLINE STATIONS AMONG THESE SOURCES, A 1975 DOLLAR VOLUME FOR THE NEUTRAL ROAD IS PROJECTED. THE OVER-ALL PREDICTION IS BASED ON INDIVIDUAL FORECASTS FOR EACH TYPE OF BUSINESS, BY COMMUNITY, USING PROJECTED CHANGES IN PARK ATTENDANCE, TRAFFIC VOLUME, AND AREA POPULATION. ADJUSTMENTS ARE MADE FOR CHANGES IN CHARACTERISTICS OF TRAFFIC AND PARK ATTENDANCE. EACH ALTERNATIVE ROUTE LOCATION IS COMPARED WITH THE NEUTRAL ROAD ON THE BASIS OF ACCESS, VISIBILITY OF ESTABLISHMENTS, DEVELOPMENTAL POTENTIAL, ADVERTISING RESTRICTIONS, AND ANTICIPATED DRIVER BEHAVIOR. /AUTHOR/]]></description><pubDate>Fri, 05 Aug 1994 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/93138</guid></item><item><title>NEW YORK COURT HOLDS REVOCABLE LICENSE TO USE CONDEMNED EASEMENT FOR ACCESS TO REMAINING LAND CANNOT BE CONSIDERED IN DETERMINING SEVERANCE DAMAGES BUT STATE SHOULD GRANT UNREVOCABLE PERMIT IN ORDER TO MITIGATE DAMAGES</title><link>http://pubsindex.trb.org/view/128460</link><description><![CDATA[THE CLAIMANT OWNED A 156 PLUS-ACRE TRACT OF LAND WHICH WAS BEST SUITED FOR RESIDENTIAL PURPOSES. THE STATE APPROPRIATED SOME OF THE LAND FOR HIGHWAY PURPOSES AND FOR TWO PERMANENT EASEMENTS. HOWEVER, RESTRICTIONS WERE SET UP FOR THE EASEMENTS AND THE OWNER FELT THAT HE HAD NO REASONABLE MEANS OF ACCESS TO HIS PROPERTY AND THAT THE REMAINDER OF THE PROPERTY HAD DECREASED IN VALUE. THE STATE CONTENTED THAT THE CLAIMANT HAD SUFFERED NO LOSS OF ACCESS SINCE HE COULD BUILD A BRIDGE ACROSS THE PERMANENT EASEMENTS AND THAT, THEREFORE, THE ONLY DAMAGE TO THE REMAINING PROPERTY WAS THE COST OF CONSTRUCTING ACCESS ACROSS THE EASEMENTS. THE COURTS RULED THAT THE STATE SHOULD BE PERMITTED TO AUTHORIZE THE CONSTRUCTION OF A BRIDGE WITH A RIGHT TO ITS USE AND, IF THE STATE FAILED TO GRANT THE AUTHORIZATION THEN SEVERANCE DAMAGES TO BE BASED UPON THE COSTS OF THE BRIDGE AND OTHER DAMAGES WOULD BE AWARDED. ALSO, THE CLAIMANT COULD MAKE FUTURE CLAIMS IF HIS ACCESS RIGHTS WERE INTERFERED WITH. (WOLFE V. STATE, 259 N.Y.S. 2D 13, MAY 1965)]]></description><pubDate>Thu, 10 Feb 1994 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/128460</guid></item><item><title>SIMPLE METHODS FOR ESTIMATING BACKWATER AND CONSTRICTION SCOUR AT BRIDGES AND ABRUPT ENCROACHMENTS</title><link>http://pubsindex.trb.org/view/202838</link><description><![CDATA[Analytic expressions for bridge backwater and constriction scour are presented for subcritical flow through five commonly occurring bridge crossings.  To assess the effects of constriction scour on bridge backwater, a known cross-section technique is employed.  Based on the analytic expressions, bridge backwater and constriction scour are numerically simulated over a wide range of flow conditions.  Regression analysis is used to develop simplified explicit relations for bridge backwater as a function of Froude number, pier energy-loss coefficient, constriction ratio, and conveyance ratio.  The resulting regression equations are sufficiently accurate for preliminary hydraulic analyses of bridge waterways in a feasibility study.  Simplified expressions are not intended for detailed design analysis.  Practical application of the simplified expressions is illustrated through a step-by-step design procedure.  (Author)]]></description><pubDate>Mon, 30 Apr 1984 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/202838</guid></item><item><title>EVALUATING EFFECTIVENESS OF LANE-USE CONTROL DEVICES AT INTERSECTIONS</title><link>http://pubsindex.trb.org/view/116899</link><description><![CDATA[FIELD STUDIES WERE MADE AT SEVERAL HIGH-VOLUME SIGNALIZED INTERSECTIONS IN THE CHICAGO AREA TO EVALUATE THE EFFECTIVENESS OF DIFFERENT DESIGNS OF ROADSIDE AND OVERHEAD TRAFFIC SIGNS FOR CONTROLLING MULTIPLE TURNS (DOUBLE-LEFT TURNS OR DOUBLE-RIGHT TURNS). THE COMPARATIVE EFFECTIVENESS OF DIFFERENT ROADSIDE DOUBLE-TURN SIGNS WAS ALSO STUDIED IN THE LABORATORY BY MEASURING RESPONSE TIMES AND ACCURACY OF RESPONSES TO QUESTIONS ASKED OF GROUPS OF SUBJECTS CONCERNING THEIR INTERPRETATIONS OF TEST SIGNS, WHEN SHOWN IN RELATION TO SIMULATED DRIVING SITUATIONS. SLIDES WERE USED TO DISPLAY THE DRIVING SITUATIONS AND THE TEST SIGNS. IT WAS FOUND THAT EFFECTIVENESS OF MULTI-TURN CONTROLS COULD BE EVALUATED IN THE FIELD BY STUDYING CHANGES IN THE USE OF THE SECOND, OR OPTIONAL, LANE FOR TURNS, COUPLED WITH OBSERVATIONS OF VIOLATIONS OF LANE-USE CONTROLS. IN THE LABORATORY THE QUESTIONS ON ACCURACY OF RESPONSE APPEARED TO PROVIDE THE MOST USEFUL INFORMATION FOR EVALUATION OF EFFECTIVENESS OF DOUBLE-TURN CONTROL SIGNS. IT WAS CONCLUDED THAT THE REGULATORY LANE-USE CONTROL SIGNS IN THE 1961 EDITION OF MANUAL ON UNIFORM TRAFFIC CONTROL DEVICES SHOULD BE SATISFACTORY FOR CONTROL OF MULTIPLE TURNS, UNTIL REFINEMENTS ARE DEVELOPED FROM FURTHER RESEARCH. /HRB/]]></description><pubDate>Mon, 24 Jan 1972 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/116899</guid></item><item><title>REDUCING MOTORIST INCONVENIENCE DUE TO MAINTENANCE OPERATIONS ON HIGH-VOLUME FREEWAYS</title><link>http://pubsindex.trb.org/view/113745</link><description><![CDATA[MUDJACKING OPERATIONS ALONG THE SAN DIEGO FREEWAY REQUIRED THAT CONCRETE SLABS BE PLACED IN TWO-LANE SECTIONS. THE SCHEDULING AND TRAFFIC-CONTROL PRACTICES EMPLOYED TO MINIMIZE DELAY DURING THIS THREE-MONTH TASK ARE DESCRIBED.]]></description><pubDate>Tue, 29 Jun 1971 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/113745</guid></item></channel></rss>