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    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <language>en-us</language>
    <copyright>Copyright © 2026. 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>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>Analytical Framework for Life Cycle and Performance Assessment of Equipment Programs</title>
      <link>https://trid.trb.org/View/1858088</link>
      <description><![CDATA[In this project, the authors analyzed the optimal life cycles for three types of trucks for the Utah Department of Transportation (UDOT) using a macro-level approach. The types of truck include loaders, graders, and sweepers. The life cycle analysis follows a similar procedure with respect to the optimal life cycle analysis for Class 8 snowplow trucks that was conducted in 2019. Currently, UDOT has managed these trucks since 1988. The increase of service span leads to lower performance efficacy and higher maintenance costs. To this end, the authors performed a data-driven approach for optimal life cycle analysis. The numerical results indicated different replacement cycles for the three types of trucks. Specifically, the optimal life cycle for sweepers is 4 years due to its relatively lower purchase price and high maintenance cost. In contrast, the optimal life cycles for loaders and graders are 8 and 9 years, respectively. Moreover, the authors analyzed the life cycles and total costs under different scenarios, and subsequently provided appropriate time windows for truck replacement.]]></description>
      <pubDate>Thu, 24 Jun 2021 16:43:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/1858088</guid>
    </item>
    <item>
      <title>Lifting and parallel lifting optimization by using sensitivity and fuzzy set for an earthmoving mechanism</title>
      <link>https://trid.trb.org/View/1624175</link>
      <description><![CDATA[Earthmoving equipment in motor graders, which can be considered to be complex multibody systems (MBSs), are critical components for earthwork, compaction and re-handling. They have not yet received much attention due to their unusual applications and complicated structures. In this paper, a comprehensive study of an earthmoving MBS, from the mechanism identification and sensitivity analysis to the multi-objective optimization, is presented. First, the earthmoving MBS is identified to be a six degrees-of-freedom spatial hybrid mechanism, where a three revolute-revolute-prismatic-spherical (RRPS) and one spherical subchain (so, RRPS-S) spatial parallel mechanism is the key subsystem, through the mechanism analysis and synthesis. An earthmoving virtual prototyping model is built according to the system topology and connectivity. The kinematic simulations are carried out by imposing corresponding driving functions. Afterwards, the sensitivity analysis is introduced to extract several most relevant design variables from the global ones. A multi-objective optimization process is carried out to improve working performance, where fuzzy sets are used to define different objectives. Results show that the optimal earthmoving mechanism provides better lifting and parallel lifting capabilities.]]></description>
      <pubDate>Wed, 29 Jan 2020 14:30:07 GMT</pubDate>
      <guid>https://trid.trb.org/View/1624175</guid>
    </item>
    <item>
      <title>Optimizing Maintenance Equipment Life-Cycle for Local Agencies</title>
      <link>https://trid.trb.org/View/1676077</link>
      <description><![CDATA[Determining the optimal time of equipment replacement is challenging, since the cost of maintaining road equipment increases with equipment operation, while the economic value of the equipment decreases. Accurately estimating the optimal replacement time and predicting future costs of road equipment contribute to the effective use of equipment, while avoiding expensive maintenance activities. This research project developed a data-driven equipment life-cycle cost analysis (LCCA) model that estimates economic life, replacement time, and future costs of motor graders and trucks for Iowa counties. The current practice of equipment management in Iowa counties was studied by conducting a survey and a follow-up interview. Historical equipment management data for motor graders and trucks were explored to perform regression analysis and derive equipment cost estimation models. A spreadsheet-based tool was also developed to capture equipment data and provide cost estimation and optimal replacement time. The tool has two modules: (1) deterministic analysis that captures single values as inputs and provides one-point estimation and (2) stochastic analysis, in which a range of values is captured and Monte Carlo simulation is used to provide a range of values as results. The stochastic analysis provides insights about the effect of uncertainties associated with variables to more realistically reflect actual practice. The tool considers both purchasing and leasing options to be applicable for counties that use each method of equipment acquisition. The research also proposed a template for equipment data record keeping that meets LCCA requirements and allows counties to improve their data collection practices, which can enhance equipment planning over time. The output of this project not only allows Iowa county engineers to support their equipment decisions but also can be used as an example of equipment LCCA for other public agencies.]]></description>
      <pubDate>Mon, 06 Jan 2020 17:27:18 GMT</pubDate>
      <guid>https://trid.trb.org/View/1676077</guid>
    </item>
    <item>
      <title>Colored Petri Net Simulation Model to Allocate Motor Graders for Earthmoving Operations</title>
      <link>https://trid.trb.org/View/1542352</link>
      <description><![CDATA[Earthmoving processes are extremely important for road construction because of the high costs involved. Discrete-event simulation has been used as a decision-support tool for earthworks planning and operation in the last few decades; however, less attention has been paid to leveling processes, despite their practical importance. This paper aims at presenting a colored Petri net (CPN) model for the allocation of motor graders in earthmoving operations. The proposed approach was implemented on CPN Tools and addressed several factors, such as the experience of operators and the probabilistic nature of the operation. A case study in a real-world problem is presented, with a simulation of 46 types of motor graders and 3 types of crews. The results indicate that significant gains may be achieved in terms of the reduction of operational costs and planning time through the application of the proposed model.]]></description>
      <pubDate>Mon, 22 Oct 2018 09:20:03 GMT</pubDate>
      <guid>https://trid.trb.org/View/1542352</guid>
    </item>
    <item>
      <title>Vermont Demonstration Project: Stockbridge-Bethel Roadway Reclamation Project</title>
      <link>https://trid.trb.org/View/1373006</link>
      <description><![CDATA[As a part of the HIghways for LIFE (HfL) initiative, the Federal Highway Administration (FHWA) provided a $1,900,000 grant to the Vermont Agency of Transportation for the Stockbridge-Bethel roadway reclamation project. The Stockbridge-Bethel project involved reclaiming the roadway that spanned 9.7 miles over VT RT-107 from the new through-truss bridge in the town of Bethel to Stockbridge, where RT-107 intersects VT Route 100. The work performed on this project included cold planing, reclamation of the existing roadway, base stabilization, superelevation and other minor geometric improvements, resurfacing with new base, intermediate, and wearing surfaces, new pavement markings, guardrail improvements, drainage improvements, and other incidental items. The project scope also included the construction of a new park and ride facility. The Stockbridge-Bethel roadway reclamation project included the use of the following technologies: Global positioning system (GPS) surveying equipment; GPS-equipped machine graders; Intelligent compaction (IC) equipment mounted on both dirt and pavement rollers; and Infrared thermal imaging equipment mounted on the back of the paver. These technologies helped with the real-time monitoring of roadway construction and served as important quality assurance tools to both the contractor and the resident engineer over the duration of the project.]]></description>
      <pubDate>Wed, 04 Nov 2015 14:30:19 GMT</pubDate>
      <guid>https://trid.trb.org/View/1373006</guid>
    </item>
    <item>
      <title>Engine Variable Impact Analysis of Fuel Use and Emissions for Heavy-Duty Diesel Maintenance Equipment</title>
      <link>https://trid.trb.org/View/1339556</link>
      <description><![CDATA[Heavy-duty diesel maintenance equipment consumes significant amounts of fuel and consequently emits substantial quantities of pollutants. The purpose of this study was to identify which engine activity variables had the greatest impact on fuel use and emissions rates. A real-world data set was used for a case study fleet containing backhoes, motor graders, and wheel loaders. Multiple linear regression was used to assess the relationships between engine activity variables and fuel use and emissions rates. The engine activity variables of engine speed, manifold absolute pressure, and intake air temperature were used to predict mass per time fuel use and emissions rates of nitrogen oxides, hydrocarbons, carbon monoxide, carbon dioxide, and particulate matter. The results indicated that manifold absolute pressure had the greatest impact on fuel use and emissions rate predictions. Based on this finding, fuel use and emissions estimating models based on manifold absolute pressure were developed as a practical estimating tool for practitioners.]]></description>
      <pubDate>Tue, 27 Jan 2015 11:22:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/1339556</guid>
    </item>
    <item>
      <title>Roads to Rubble: De-Paving a Half-Century of Progress</title>
      <link>https://trid.trb.org/View/1104206</link>
      <description><![CDATA[The economic crisis of recent years has led some rural counties to replace asphalt pavements with gravel. Over a 20 year cycle a low-use rural road in South Dakota typically costs $32,000 per mile per year as compared to $1,700 for gravel. The cost effectiveness of de-paving is determined largely by traffic volume. One study shows gravel roads are economically feasible with less than 170 ADT (average daily traffic) and at more than 650 ADT it becomes more economical to maintain asphalt pavement. Options for traffic volumes between 170 and 650 ADT include a deep aggregate base with a top coat of asphalt or a damp aggregate base covered by an emulsion.]]></description>
      <pubDate>Thu, 23 Jun 2011 09:07:07 GMT</pubDate>
      <guid>https://trid.trb.org/View/1104206</guid>
    </item>
    <item>
      <title>The Wages of Smart</title>
      <link>https://trid.trb.org/View/980801</link>
      <description><![CDATA[This article describes how completing the early stages of road building is all about doing it right the first time with new technology, say equipment manufacturers. When an equipment owner sends his gear and his people out on a road-building project, it’s not only about completing his portion of the project as contracted. What contractors will say is that they usually have three goals for a job: One is that they do it safely and no one gets hurt. The second is that they move the dirt one time; they don’t want to have to pay in terms of fuel and other expenses to move it more than once. And the last thing is that they move it fast. Machine control guidance really helps with all three of those. Construction equipment manufacturers indicated that, for sub-grade and sub-base work especially, any current trend in machinery is not about the equipment itself, but the smart technology available to most efficiently use the equipment. In some cases, grade and other machine control systems are offered by those same original equipment manufacturers (OEMs);]]></description>
      <pubDate>Tue, 26 Oct 2010 09:54:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/980801</guid>
    </item>
    <item>
      <title>Cool Graders</title>
      <link>https://trid.trb.org/View/918516</link>
      <description><![CDATA[This article describes how the grader operator is king on the job. Nobody dares get in his way … and, should anyone need to tell him anything, such a task is left to only the most senior of supervisors. The “blade hand” is staunchly independent, often gruff, and yet universally admired and respected. Rarely is there another equipment operator within 50 miles who can, be it with traditional lever or breakthrough joystick in hand, feel his way from rough ground and raw material to the glass-like smoothness that will cradle the office buildings, parking lots and roadways to come. It stands to reason, then, that the king’s carriage is maintained with discipline and order, whether it be driven through snow or dust, be it tasked with winging back drifts on a blizzard-closed township road in Minnesota or carving through barren hardscrabble in west Texas. With the summer work season underway, there are some particular maintenance issues to keep in mind.]]></description>
      <pubDate>Sun, 30 May 2010 07:44:11 GMT</pubDate>
      <guid>https://trid.trb.org/View/918516</guid>
    </item>
    <item>
      <title>Comprehensive Field Study of Fuel Use and Emissions of Nonroad Diesel Construction Equipment</title>
      <link>https://trid.trb.org/View/910721</link>
      <description><![CDATA[Limited field data are available for analyses of fuel use and emissions of nonroad diesel construction equipment. This paper summarizes the results of field research that used a portable emissions monitoring system to collect fuel use and emissions data from eight backhoes, six bulldozers, three excavators, four generators, six motor graders, three off-road trucks, one skid-steer loader, three track loaders, and five wheel loaders while they performed various duty cycles. These tests produced approximately 119 h of field data for petroleum diesel and approximately 48 h for B20 biodiesel. Engine attribute data including horsepower, displacement, model year, engine tier, and engine load were collected to determine these factors’ influence on fuel use rates and emission rates of nitrogen oxides, hydrocarbons, carbon monoxide, carbon dioxide, and opacity. Mass per time fuel use rates were developed for each item of equipment, as were mass per time and mass per fuel used emission rates for each pollutant. For petroleum diesel, fuel use and emission rates of each pollutant were found to increase with engine displacement, horsepower, and load and to decrease with model year and engine tier. The results were qualitatively similar for B20 biodiesel. Fuel-based emission rates were found to have less variability and less sensitivity to engine size and load than time-based emission rates. Where possible, development of emission inventories based on fuel consumed, rather than time of activity, is preferred.]]></description>
      <pubDate>Tue, 16 Mar 2010 06:13:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/910721</guid>
    </item>
    <item>
      <title>The Use of Roller-Compacted Concrete (RCC) Pavements in the United States</title>
      <link>https://trid.trb.org/View/899345</link>
      <description><![CDATA[This paper describes how roller-compacted concrete (RCC) pavements are economical, heavy-duty alternatives to conventional asphalt or Portland cement concrete pavements. RCC pavements have been used in the United States for over 25 years now, and their application has evolved from tank trails for the military to parking and storage facilities at major automobile manufacturing plants. The technology has evolved as well, from spreading the fresh concrete using motor graders to the use of sophisticated, heavy-duty, asphalt paving screeds. This paper reviews the history of applications and the evolution of the technology and materials of RCC pavements in the United States. It will speak to both the advantages and limitations of RCC pavements for those who might consider its use in these and other applications.]]></description>
      <pubDate>Mon, 31 Aug 2009 09:25:18 GMT</pubDate>
      <guid>https://trid.trb.org/View/899345</guid>
    </item>
    <item>
      <title>Characterization of In-Use Emissions from TxDOT's Non-Road Equipment Fleet – Phase 1 Report</title>
      <link>https://trid.trb.org/View/892094</link>
      <description><![CDATA[The objective of this document is to present the preliminary findings of the study characterizing in-use Texas Department of Transportation (TxDOT) non-road diesel equipment emissions. This document presents literature reviews of emissions reduction technologies and emissions control measures practiced by the state of Texas and other states, discusses selection of TxDOT non-road equipment and emissions reduction technologies for emissions testing, and shows preliminary results of in-use emissions of TxDOT diesel equipment using portable emissions measurement systems (PEMS). Emissions measurements and data comparison and analysis tasks are still ongoing, so that a stage for any recommendation or conclusion has not been reached.]]></description>
      <pubDate>Thu, 02 Jul 2009 16:01:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/892094</guid>
    </item>
    <item>
      <title>Development and Use of Emissions Inventories for Construction Vehicles</title>
      <link>https://trid.trb.org/View/881203</link>
      <description><![CDATA[Real-world data are insufficient to estimate actual emissions from construction vehicles and to develop effective decisions aimed at reducing emissions. A methodology is developed here for inventorying construction fleet emissions on the basis of representative real-world measurements of construction vehicles by means of a portable emissions measurement system (PEMS). The PEMS enables measurements of actual duty cycles and their corresponding fuel use and emissions. The methodology is demonstrated via application to a fleet of publicly owned construction vehicles used primarily for highway maintenance. Selected backhoes, front-end loaders, and motor graders, representing various model years and engine emissions standards, were measured with PEMS during use. Tests were performed for B20 biodiesel and petroleum diesel (PD) fuels. Emission factors from the PEMS data, combined with owner records of annual fuel consumption for over 1,000 vehicles, were used to estimate annual inventories of tailpipe emissions of nitrogen oxides, particulate matter, hydrocarbons, and carbon monoxide. The emissions inventory was stratified by pollutant, vehicle type, fuel type, and engine tier and was used to assess fleet management strategies aimed at reducing emissions. Case study results illustrate that total fleet emissions would be reduced by 3% to 24% when B20 fuel was being used exclusively instead of PD exclusively, 11% to 50% when all Tier 0 and Tier 1 engines were replaced with Tier 2 engines, and 31% to 72% when B20 fuel was used exclusively in the highest engine tier available. Recommendations are made about development and practical applications of emissions inventories for construction fleet management.]]></description>
      <pubDate>Fri, 17 Apr 2009 09:56:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/881203</guid>
    </item>
    <item>
      <title>Cutting-Edge Maintenance Tips to Keep Motor Graders Fit and Productive</title>
      <link>https://trid.trb.org/View/864736</link>
      <description><![CDATA[Motor graders must be properly maintained so that they remain responsive to operator commands.  This article provides some guidelines on how to maintain motor graders.  Keeping a good cutting edge on the moldboard (blade) is the key to good motor grader maintenance.  Because the cutting edges of the moldboard are constantly engaged with the material, they wear out quickly depending on hours of use, abrasiveness of material and operator skill.  Air filters, tires, scarifiers also need regular inspection and maintenance.  The operator station and controls are often overlooked, but can have a significant effect on operator safety and machine responsiveness if they are not maintained properly.]]></description>
      <pubDate>Mon, 28 Jul 2008 14:07:26 GMT</pubDate>
      <guid>https://trid.trb.org/View/864736</guid>
    </item>
    <item>
      <title>Comparison of Real-World Emissions of B20 Biodiesel Versus Petroleum Diesel for Selected Nonroad Vehicles and Engine Tiers</title>
      <link>https://trid.trb.org/View/847972</link>
      <description><![CDATA[Field data for in-use fuel consumption and emission rates were collected for 15 nonroad vehicles by using a portable emission measurement system. Five backhoes, four front-end loaders, and six motor graders were tested once on petroleum diesel and once on B20 biodiesel. The vehicles represented a variety of engine certification tiers. A methodology was developed for study design, field data collection, data screening and quality assurance, data analysis, and benchmarking of the data. On average, 6.9% of data were lost because of quality issues and more than 3 h of valid data were collected in each test. Time-based emission factors increased monotonically with respect to engine manifold absolute pressure. Fuel-based emission factors were sensitive to differences between operations of engines idling and not idling. Typical duty cycles were quantified in terms of frequency distributions of manifold absolute pressure and used to estimate cycle average emission factors. On average, the use of B20 instead of petroleum diesel led to an insignificant 1.8% decrease in the nitric oxide (NO) emission rate and significant decreases of 18%, 26%, and 25% for opacity, hydrocarbons (HC), and carbon monoxide (CO), respectively. Emission rates decreased significantly in newer, higher-tier vehicles compared with older ones. Fuel use, NO, HC, and CO data were of similar magnitude as independent benchmark data. Specific recommendations were made for future work.]]></description>
      <pubDate>Mon, 25 Feb 2008 14:33:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/847972</guid>
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