<rss version="2.0" xmlns:atom="https://www.w3.org/2005/Atom">
  <channel>
    <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" />
    <description></description>
    <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>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
    </image>
    <item>
      <title>Low Frequency Noise Study</title>
      <link>https://trid.trb.org/View/2114141</link>
      <description><![CDATA[This document is the final report of the Partnership for AiR Transportation Noise and Emissions Reduction (PARTNER) low-frequency noise study. Section 1 is the Executive Summary. Section 2 contains an overview of the study. Section 3 contains background including a summary of previous studies of low-frequency noise around airports and objective metrics used to predict low-frequency noise annoyance. Section 4 discusses how this study addresses Federal Interagency Commission on Aviation Noise (FICAN) recommendations. The process used to select an airport for the field measurement part of this study, along with the design of the field measurement, are described in Section 5. Section 6 presents the results of the source noise measurements. The noise and vibration impact on residential structures are discussed in Section 7. Section 8 describes the design and results of the subjective tests, while Section 9 details the rattle and low-frequency sound insulation parts of the study. Section 10 summarizes the study and lists the principal findings and recommendations. This study included field measurements at Washington Dulles International Airport, laboratory-based subjective jury trials, and laboratory-based rattle and low frequency sound insulation studies.]]></description>
      <pubDate>Tue, 14 Feb 2023 17:48:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/2114141</guid>
    </item>
    <item>
      <title>Reagan National Airport: Information on Effects of Federal Statute Limiting Long-Distance Flights</title>
      <link>https://trid.trb.org/View/1753526</link>
      <description><![CDATA[Reagan National’s perimeter and slot control rules were designed in part, respectively, to help increase use of Dulles and manage congestion at Reagan National by limiting the number of flights. On three occasions—2000, 2003, and 2012— federal statutes have provided exemptions to the perimeter rule, collectively allowing 40 daily beyond-perimeter flights (20 round trips) at Reagan National. Of these exemptions, 32 were new beyond-perimeter flights and eight allowed airlines to convert existing slots to beyond-perimeter flights. The Metropolitan Washington Airports Authority (MWAA) operates Reagan National and Dulles, and DOT and the Federal Aviation Administration (FAA) oversee these rules. The Government Accountability Office (GAO) was asked to update its past work on the perimeter rule. This report describes (1) the effects of beyond-perimeter flights at Reagan National, and (2) key considerations if additional beyond-perimeter flights are allowed. GAO analyzed DOT data for the most recent 10-year period (2010 through 2019) on passengers and flights at Reagan National and Dulles, and MWAA data on airport capacity at Reagan National in 2019. GAO also reviewed relevant statutes and regulations, and interviewed DOT and FAA officials, and a non-generalizable sample of 32 stakeholders: 9 airlines, 4 airport authorities, 7 academics, 5 associations, 5 community groups, and 2 consumer advocates. Selected airlines included those that operate out of Reagan National or Dulles; other stakeholders were recommended or selected, in part, from prior GAO work and their expertise on the topic.]]></description>
      <pubDate>Mon, 07 Dec 2020 09:48:10 GMT</pubDate>
      <guid>https://trid.trb.org/View/1753526</guid>
    </item>
    <item>
      <title>Measuring Performance at a Large Metropolitan Area: The Case of the DC (District of Columbia) Metroplex</title>
      <link>https://trid.trb.org/View/1662252</link>
      <description><![CDATA[Hierarchical linear models improve the measurement of performance when applied to a construct such as a metroplex. It compares the outcomes of a hierarchical linear model with those of a multiple regression model to evaluate whether meteorological conditions at individual airports and overall would explain variations in block delays. The study used the cases of the three largest airports in the DC Metroplex and concluded airborne delays had a significant random effect on block delays in spite of meteorological conditions at each airport. It pointed out that surface operations efficiency played a significant role in explaining variations in block delays.]]></description>
      <pubDate>Thu, 02 Apr 2020 09:43:02 GMT</pubDate>
      <guid>https://trid.trb.org/View/1662252</guid>
    </item>
    <item>
      <title>Taming the Multi-Stakeholder Hydra: Permitting, Design, and Tunneling a Sewer across the Dulles International Airport and the Metrorail Silverline</title>
      <link>https://trid.trb.org/View/1639138</link>
      <description><![CDATA[This case study will discuss the intricacies in planning, designing, permitting, and constructing a large-scale gravity sewer across the Dulles International Airport and with four tunneled crossings of the Washington Metropolitan Area Transportation Authority’s Metrorail Silverline (Phase 2). The sewer was designed to serve Loudoun Water in Loudoun County, VA. Located just west of Washington, DC, in one of the fastest growing areas in the country, this new sewer is needed to meet Loudoun’s projected wastewater demands in their Horsepen Run sewershed. This paper will outline the strategies implemented by the project team to facilitate and expedite stakeholders review and approval of the 20,000 linear-foot large diameter sewer (72/48/42 inch). In addition, the paper will outline how the scalable risk management strategy employed aided in maximizing value for Loudoun Water while minimizing risk.]]></description>
      <pubDate>Fri, 21 Feb 2020 17:25:17 GMT</pubDate>
      <guid>https://trid.trb.org/View/1639138</guid>
    </item>
    <item>
      <title>Steady-State Car-Following Time Gaps: An Empirical Study Using Naturalistic Driving Data</title>
      <link>https://trid.trb.org/View/1607512</link>
      <description><![CDATA[The time gap is defined as the time difference between the rear of a vehicle and the front of its follower, which affects both safety and the saturation flow rate of a roadway segment. In this study, naturalistic driving data were examined to measure time gaps from seven different drivers in a car-following scenario within steady-state conditions. The measurements were taken from a 13-km section of a Dulles Airport access road in Washington, DC. In total, 168,053 time gap samples were obtained covering seven speed intervals. Analysis of the data revealed a large variation in time gaps within individual drivers’ driving data, with coefficients of variation as high as 63.8% observed for some drivers. Results also showed that the variability within drivers was more significant at speeds higher than 54 km/h. In addition, there was a large variability between drivers. At speeds above 108 km/h, minimum time gaps left by some drivers could be 1.6 times longer than those left by others. Several statistical distributions were used to fit the data of the seven drivers as well as the data for all drivers combined for each speed interval. The selected distributions passed the goodness-of-fit (Kolmogorov-Smirnov, Chi-square, and Anderson-Darling) criteria only when the number of samples was reduced. Data reduction was not performed randomly, but rather in a manner intended to maintain the same observed distribution when all the samples were used. It is therefore recommended that empirical measures of distributions be used in traffic microsimulation software rather than theoretically fit distributions obtained based on statistical tests. This will lead to better naturalistic traffic behavior simulations, resulting in more precise predicted measures of performance (travel time, fuel consumption, and gas emissions).]]></description>
      <pubDate>Wed, 18 Sep 2019 09:17:02 GMT</pubDate>
      <guid>https://trid.trb.org/View/1607512</guid>
    </item>
    <item>
      <title>Innovation in Cement Stabilization of Airfield Subgrades</title>
      <link>https://trid.trb.org/View/1428731</link>
      <description><![CDATA[The Washington Dulles International Airport (IAD) is located in Loudon and Fairfax Counties in northeastern Virginia, approximately 26 miles northwest of Washington, D.C. The Metropolitan Washington Airports Authority (the Authority) reconstructed the original 10,000 feet of Runway 12-30 at IAD with Portland cement concrete pavements. The geotechnical investigation concluded that extensive areas of the runway subgrades are weak and needed to be addressed. The three main options to address the weak subgrades were: i) Undercut the poor subgrades and replace them with good quality borrow materials with a minimum California Bearing Ratio (CBR) value of 20; ii) Crush the demolished concrete pavement structure and use it as crushed recycled concrete base to improve the subgrade support conditions; and iii) Addition of small amounts of ordinary Portland cement to the top 12 inches of the existing subgrades. The Authority, in conjunction with the design team, chose Option iii as it gave them the most realistic chance of completing the project within budget and on schedule. This paper presents the mixture design process of the cement stabilized subgrade soils for the reconstruction of Runway 12-30 at IAD. This paper describes a laboratory study aimed at designing cement stabilized subgrade soils that satisfy the following: i) Optimal shrinkage and durability in addition to strength; ii) Early opening to construction traffic within 3-days of curing; and iii) Innovative acceptance criteria to ensure that good quality is obtained in an accelerated construction schedule.]]></description>
      <pubDate>Mon, 21 Nov 2016 13:43:34 GMT</pubDate>
      <guid>https://trid.trb.org/View/1428731</guid>
    </item>
    <item>
      <title>Optimizing Ridesharing Services for Airport Access</title>
      <link>https://trid.trb.org/View/1288707</link>
      <description><![CDATA[This paper addresses the problem of optimally routing and scheduling airport shuttle vehicles that offer pickup and drop-off services to customers through ridesharing. This problem, which is a version of the dial-a-ride problem, is formulated as a mixed integer program. For the solution, an exact approach applying constraint programming in a column generation framework and the adaptation of two existing heuristics are proposed. Implementations of the mathematical program and proposed solution approaches for three operational policies are presented. The performance of the proposed approaches in regard to computational requirements and solution quality was evaluated in a real-world case study involving service records for one service day out of Washington, D.C., Dulles International Airport in Chantilly, Virginia, provided by an actual airport shuttle service provider. Results show that the heuristics provide good approximations to the exact solution.]]></description>
      <pubDate>Mon, 24 Mar 2014 12:02:01 GMT</pubDate>
      <guid>https://trid.trb.org/View/1288707</guid>
    </item>
    <item>
      <title>A Capital System Keeps Growing</title>
      <link>https://trid.trb.org/View/1238291</link>
      <description><![CDATA[This article describes how the Washington Metropolitan Area Transit Authority (WMATA) has evolved since its inception in 1976. There are new lines, new equipment and even new rail modes currently being constructed as part of an ambitious agenda for the Washington DC area. There are new cars being targeted for the Dulles Corridor and new modes are being constructed at four locations in Maryland.]]></description>
      <pubDate>Wed, 23 Jan 2013 09:08:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/1238291</guid>
    </item>
    <item>
      <title>Guidance for Quantifying the Contribution of Airport Emissions to Local Air Quality</title>
      <link>https://trid.trb.org/View/1141562</link>
      <description><![CDATA[This report is a guide for airport operators on effective procedures for using air quality models in combination with on-site measurement equipment to prepare a comprehensive assessment of air pollutant concentrations in the vicinity of airports.  It is designed to help practitioners generate information desired by local communities as they seek to develop more detailed local air quality assessments as well as respond to regulatory needs, including those of the National Environmental Policy Act (NEPA).  The guide provides in-depth information on the capabilities and limitations of modeling and measurement tools, adding to an increasing knowledge base concerning preparation of air quality assessments near airports.  Starting with the Federal Aviation Administration's (FAA's) regulatory EDMS/AEDT, it describes how best to use available models, in combination with potential on-site monitoring programs, to conduct air quality assessments.  Detailed information on the monitoring campaigns and modeling assessments is included in a set of appendices that accompany the guide.  The appendices (available in CRP-CD-115) describe the models tested and the various equipment used to collect data, the rationale behind the selection of Washington Dulles International Airport as a case study application, and the components and steps involved in the measurement campaigns, and include an assessment of the various model outputs.]]></description>
      <pubDate>Tue, 26 Jun 2012 07:44:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/1141562</guid>
    </item>
    <item>
      <title>Dulles International Airport Automated People Mover System: Design and Construction of the Main Terminal and Tier 2 Stations</title>
      <link>https://trid.trb.org/View/1123252</link>
      <description><![CDATA[Eero Saarinen's mobile lounge system was recognized as state of the art intra-airport transportation of airline passengers in 1960. A half century later, in order to maintain the cutting edge airport operations and to position Washington Dulles International Airport to expand to meet the needs of twenty-first century airline travel, the Metropolitan Washington Airports Authority initiated a massive program to replace the mobile lounges with a fully automated people mover system. This paper presents a case study detailing some of the planning and engineering challenges encountered in the design and construction of an automated people mover system underneath an existing, high profile and fully functioning international airport. Both the first phase of the APM system that came online in January 2010, and planned extensions still to be built are discussed in relation to the airport-wide master plan. Two components of the current system are used to illustrate specific issues that were major drivers for this project: (1) Design and construction of the Main Terminal APM Station; and (2) Design and construction of the Tier 2 APM Station. The Main Terminal APM Station provides an example of a large scale, sub-grade structure built in close proximity to a functioning airline terminal. This work was further complicated by the need to respect the historic nature of the existing Dulles International Airport Main Terminal Building. The Tier 2 APM Station illustrates an opposite consideration, the construction of a facility primarily intended to service a mid-field concourse, which will be designed and built at a future date.]]></description>
      <pubDate>Wed, 14 Mar 2012 12:55:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/1123252</guid>
    </item>
    <item>
      <title>The Collaborative Process for Developing Project Definition Documents for the Metropolitan Washington Airports Authority</title>
      <link>https://trid.trb.org/View/1109473</link>
      <description><![CDATA[The conventional approach to preparing programming documents for new facilities is a process that tends to favor “stove-piping”. Once a facility is planned and a program definition document has been prepared, often the project is turned over to design, and once designed, the project is turned over to construction. Little input is derived from the designers and constructors during the planning process, and during design, the input from the planners is thought to end. Likewise, when a project that enters construction, there is less input from the designers and the planners. The Metropolitan Washington Airports Authority (Airports Authority) has sought to invest all stakeholders in the success of a project by developing a collaborative planning, design and construction process that involves all three disciplines from the conceptualization of the project through its turnover to users. The intent of the process is to make sure that the completed project meets the goals and objectives first laid out in the planning phase, and to assure that all project costs are accounted for and that goals for schedules and budgets are identified early in the process and adhered to through completion. This collaborative effort has been used with success on some initial smaller projects at both Reagan National and Washington Dulles International Airports, and is now becoming the standard process for execution of larger projects.]]></description>
      <pubDate>Mon, 08 Aug 2011 14:09:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/1109473</guid>
    </item>
    <item>
      <title>Moving Forward</title>
      <link>https://trid.trb.org/View/1093528</link>
      <description><![CDATA[The Aerotrain automated people mover (APM) system at Washington Dulles International Airport is profiled in this article. The Aerotrain was designed both to accommodate planned airport growth and replace the airport's system of mobile lounges, which shuttled passengers between terminal and tarmac in the past. Historical notes on the airport's development and growth are given. Planning and construction of completed and future APM system phases at Dulles are also detailed.]]></description>
      <pubDate>Wed, 23 Feb 2011 08:10:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/1093528</guid>
    </item>
    <item>
      <title>Dulles AeroTrain Opens: Airport Debuts Rail System</title>
      <link>https://trid.trb.org/View/917588</link>
      <description><![CDATA[This article describes the AeroTrain, introduced in January 2010 at Washington Dulles International, an underground, automated dual track rail system.  The author notes that the total AeroTrain project cost approximately $1.4 billion, including the trains, tunneling, stations, and the Main Terminal Security Mezzanine.  The article reviews the changes that were needed to incorporate enough space for security screening, passenger options, and the tunneling techniques used in the construction process.  The underground rail system was constructed while the airport continued its regular business operations, so the plan used three separate methods to excavate the tunnels.  The three methods include cut-and-cover, the New Austrian Tunneling method (for areas where the tunnels curve), and the Tunnel Boring Method (for straight sections).  Passengers enter the Main Terminal, take an escalator or elevator down to the security mezzanine and pass through a TSA security lane.  At this point, passengers have three options: board the AeroTrain to travel to the midfield concourses; continue to the Z Gates at the Main Terminal; or use the existing passenger walkway to access Concourses A and B.]]></description>
      <pubDate>Sun, 30 May 2010 07:44:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/917588</guid>
    </item>
    <item>
      <title>The Life Cycle of A Runway Pavement: A Case Study of Runway 1L-19R at The Washington Dulles International Airport</title>
      <link>https://trid.trb.org/View/904386</link>
      <description><![CDATA[In 1961, the original construction of Runway 1L-19R was completed and the pavement remained idle for approximately one year until the opening of the Washington Dulles International Airport in 1962. The pavement was designed for a 25 year life and will have been in continuous use for nearly 50 years at the time when it is scheduled for reconstruction in 2009. This paper will examine the original design parameters and the history of loading (traffic growth) over the life of the pavement. It will also discuss the active pavement management system implemented by the Authority and the subsequent maintenance activities used to extend life of this pavement. Finally, the paper will discuss the pavement design associated with the upcoming reconstruction project as the Authority attempts to match the history of performance of the original pavement life.]]></description>
      <pubDate>Tue, 17 Nov 2009 14:58:27 GMT</pubDate>
      <guid>https://trid.trb.org/View/904386</guid>
    </item>
    <item>
      <title>Using PCI Data to Define Major Rehabilitation Projects at Washington Dulles International Airport</title>
      <link>https://trid.trb.org/View/904381</link>
      <description><![CDATA[Since 2002, Washington Dulles International Airport has taken an aggressive approach to effectively managing its airfield pavement system. Each year, roughly one third of the total airfield pavement network is inspected based upon the FAA procedures, Advisory Circular 150/5380-6B, “Guidelines and Procedures for Maintenance of Airport Pavement,” to develop the Pavement Condition Index (PCI). The PCI data is used for two purposes: first, to plan for in-house annual preventive and stop-gap maintenance requirements; and second, to define major rehabilitation projects. The airport has effectively used the process to develop successful, high-impact projects to rehabilitate the original airfield pavements that are 40 to 45 years old. During the process, each major project is defined into a constructable package, with cost and duration estimates developed for each. With all projects defined, they are prioritized and fit into the operational landscape and integrated with other airfield projects. This paper explains the project definition process and components and shows how PCI inspection data can be turned into a key tool for developing an airport's plan to maintain and improve its pavement infrastructure.]]></description>
      <pubDate>Tue, 17 Nov 2009 14:58:24 GMT</pubDate>
      <guid>https://trid.trb.org/View/904381</guid>
    </item>
  </channel>
</rss>