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    <title>Research in Progress (RIP)</title>
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    <atom:link href="https://rip.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>Research in Progress (RIP)</title>
      <url>https://rip.trb.org/Images/PageHeader-wTitle-RIP.jpg</url>
      <link>https://rip.trb.org/</link>
    </image>
    <item>
      <title>Advanced Technologies and Data Analytics for Safe, Smart, and Efficient Transportation (ASSET)</title>
      <link>https://rip.trb.org/View/2709572</link>
      <description><![CDATA[This project assists the Massachusetts Department of Transportation (MassDOT) with (A) calibrating safety models for urban and suburban arterial intersections and developing artificial intelligence models for (B) detecting sidewalks and (C) counting multimodal trips.  

There are three main goals:

(A) Calibrate the Safety Performance Functions (SPFs) in Chapter 16.6.4 of the Highway Safety Manual, 2nd Edition (HSM2), along with the associated parameters, for the twelve types of urban and suburban intersections in Massachusetts using the most recent data.

(B) Develop an Artificial Intelligence (AI) model to automate the detection and mapping of sidewalks from publicly available aerial imagery. Also, the model will be used to identify changes in sidewalks using aerial imagery from multiple years.

(C) Leverage AI to automate the counting of pedestrians, active transportation modes (such as bicycles and e-scooters), and site-generated trips from new developments. The results of this task will form the basis for developing AI and/or statistical models to estimate multimodal trip counts required for transportation planning purposes.]]></description>
      <pubDate>Wed, 03 Jun 2026 15:27:05 GMT</pubDate>
      <guid>https://rip.trb.org/View/2709572</guid>
    </item>
    <item>
      <title>SPR-5130: Computational Tool for Estimating the Service-Life of Concrete Decks and Slabs</title>
      <link>https://rip.trb.org/View/2709431</link>
      <description><![CDATA[The objective of this implementation project is to deliver a calibrated and accessible computational tool that the Indiana Department of Transportation (INDOT) can use to estimate the service life of concrete bridge decks, one-way continuous solid slabs, and T-beam bridges, and to evaluate maintenance and rehabilitation scenarios. The model methodology, developed under Joint Transportation Research Program (JTRP) projects 4840 and 4526, captures the long-term effects of construction defects, environmental exposure, and common maintenance actions on deck performance, enabling prediction of the evolution of deck condition ratings under different deterioration and intervention scenarios. A user manual and user interface will be developed, and several illustrative case studies will be prepared.]]></description>
      <pubDate>Wed, 03 Jun 2026 13:33:47 GMT</pubDate>
      <guid>https://rip.trb.org/View/2709431</guid>
    </item>
    <item>
      <title>SPR-5135: CARSx Traveler Information Message (J-2735) Module Development</title>
      <link>https://rip.trb.org/View/2709429</link>
      <description><![CDATA[This project will facilitate joint engagement between Minnesota Department of Transportation (MnDOT), Indiana Department of Transportation (INDOT), and Castle Rock Associates. The objective of this proposal is to establish a collaborative, cost-sharing approach for work currently defined under an existing scope of work developed by Castle Rock for MnDOT, while ensuring that each state receives its own independent implementation.]]></description>
      <pubDate>Wed, 03 Jun 2026 13:27:41 GMT</pubDate>
      <guid>https://rip.trb.org/View/2709429</guid>
    </item>
    <item>
      <title>Improving Benefit-Cost Analysis (BCA) for Rural Application</title>
      <link>https://rip.trb.org/View/2709239</link>
      <description><![CDATA[Benefit-cost analysis (BCA) is a requirement for U.S. Department of Transportation (U.S. DOT) discretionary grant programs and plays a significant role in project evaluation and funding decisions. Rural and small urban communities often face challenges in preparing competitive BCAs due to limited technical capacity, data availability, and methodologies that may not fully capture the benefits of rural transportation investments.

Rural transportation projects can provide benefits related to economic connectivity, freight movement, access to essential services, and system resiliency, which may not be fully reflected in conventional BCA approaches. In addition, smaller communities and regional organizations may lack the staff expertise, tools, or resources needed to complete BCA requirements for funding applications.

OBJECTIVE: The objective of this research is to develop a guide to help state departments of transportation (DOTs) improve BCA methods and practices for rural and small metropolitan transportation projects. The research will identify methodological and data gaps in current BCA approaches, evaluate barriers faced by smaller communities in completing BCAs, and develop tools to support effective and competitive project evaluation processes.]]></description>
      <pubDate>Wed, 03 Jun 2026 11:51:11 GMT</pubDate>
      <guid>https://rip.trb.org/View/2709239</guid>
    </item>
    <item>
      <title>Snapshots of Planning Practices (Continued Practice Highlights)</title>
      <link>https://rip.trb.org/View/2709241</link>
      <description><![CDATA[NCHRP Project 08-36, “Research for the AASHTO Standing Committee on Planning,” was established to provide a flexible, ongoing program of quick-response research and development capabilities for states to address near-term improvements in statewide and metropolitan transportation planning, as well as project development processes. Under NCHRP Project 08-36, 138 individual tasks were completed that provided new and/or enhanced technical and policy tools to support planning processes and decision-making systems for the transportation community.

NCHRP Project 08-36(120) produced “Snapshots” of planning practices of existing and/or innovative transportation planning practices nationwide. Each Snapshot featured innovative ideas, effective practices, links to resources, and contacts for agency use to improve their transportation planning practices and results. This project was completed in 2018, with follow-up work under NCHRP Project 08-128, which was completed in 2025, both providing valuable insight to the Planning Committee. This research is needed to build on the success of the previous work and ensure timely Snapshots to be provided to the community hereafter.

OBJECTIVE: The objective of this research is to produce Snapshots of planning practices to present relevant information in the form of concise summaries of current and/or innovative transportation planning practices currently in use nationwide. The Snapshot topics chosen will represent a variety of topical subjects including practical solutions to current technical challenges, responses to legislation or administrative rules, organizational designs used by agencies to accomplish their work, and means of influencing agency decision-making.]]></description>
      <pubDate>Wed, 03 Jun 2026 11:23:02 GMT</pubDate>
      <guid>https://rip.trb.org/View/2709241</guid>
    </item>
    <item>
      <title>Incorporating Cost-Based Estimating Techniques into Bid-Based Estimating</title>
      <link>https://rip.trb.org/View/2709242</link>
      <description><![CDATA[Accurate and defensible cost estimates are critical for state departments of transportation (DOTs) to program funds, award contracts, and deliver projects on time. Most agencies rely on historical bid-based estimating, which is efficient but often fails to meet federal accuracy benchmarks. Contractors, by contrast, use cost-based estimating (CBE), building unit prices from labor, equipment, materials, and productivity. CBE is generally more accurate and defensible, especially during volatile markets or for unique items. Yet only a few state DOTs rely primarily on CBE, as compared with bid-based and hybrid approaches.

State DOTs require practical, low-burden methods to integrate CBE into bid-based workflows. Research is needed to (1) identify transferable CBE techniques that improve estimate reliability; (2) develop guidelines, decision trees, and templates for hybrid estimating; (3) define a minimum viable data specification for labor, equipment, and productivity inputs; and (4) validate guidelines developed and deliver an implementation playbook with training modules. 

The objective of this research is to provide guidance, resources, and tools based on CBE techniques that can be readily incorporated into a state DOT’s existing bid-based estimating process to produce more reliable and defensible engineer’s estimates. The desired outcome is a practical hybrid estimating framework that strengthens accuracy without requiring the full resource commitment of traditional CBE. ]]></description>
      <pubDate>Wed, 03 Jun 2026 11:18:30 GMT</pubDate>
      <guid>https://rip.trb.org/View/2709242</guid>
    </item>
    <item>
      <title>Evaluating Large-Scale UAS Technologies and Current Implementation Practices for State DOT Infrastructure Operations</title>
      <link>https://rip.trb.org/View/2709243</link>
      <description><![CDATA[The use of unmanned aircraft systems (UASs) in transportation operations has expanded rapidly over the past decade. State departments of transportation (DOTs) now routinely deploy small UASs for asset inspection, mapping, and incident management. However, most operations remain limited to small-scale, pilot-controlled flights under visual line-of-sight (VLOS) conditions. The next major advancement involves the integration of large-scale (group 3+) UASs capable of extended range, higher payloads, and broader data collection, transforming how agencies monitor and maintain transportation infrastructure.

 Larger UASs equipped with advanced sensors, automated navigation, and real-time data analytics offer significant potential benefits for DOTs. These systems could enable persistent infrastructure monitoring, automated right-of-way surveys, and rapid disaster response across large geographic areas. When deployed strategically, fleets of UASs could conduct scheduled bridge inspections, detect pavement distress, or assess storm damage in near-real time.

 While the private sector and federal agencies such as the Federal Aviation Administration (FAA), National Aeronautics and Space Administration (NASA), and Department of Homeland Security (DHS) are advancing research in large-scale UAS technologies, few studies have assessed how these capabilities align with state DOT operational needs and regulatory environments. Key challenges remain in areas such as beyond visual line of sight (BVLOS) authorization, cybersecurity, airspace integration, data management, and interoperability with existing DOT information technology systems.

 The objective of this research is to evaluate large-scale (group 3+) UAS technologies and assess how these systems can be effectively integrated into state DOT support operations. The research will identify current and emerging UAS platforms suitable for infrastructure inspection, traffic monitoring, emergency response, and environmental assessment.

 This research will review existing implementations by U.S. state DOTs, universities, and other public agencies, identifying best practices, operational benefits, budgeting, funding acquisition, challenges, and gaps in policy, technology, and workforce capability. Key outcomes will include operational frameworks for safe deployment and actionable recommendations for regulatory alignment, interagency coordination, and technology adoption strategies.]]></description>
      <pubDate>Wed, 03 Jun 2026 11:09:10 GMT</pubDate>
      <guid>https://rip.trb.org/View/2709243</guid>
    </item>
    <item>
      <title>Development of a Materials Sampling and Testing Safety Guide</title>
      <link>https://rip.trb.org/View/2709245</link>
      <description><![CDATA[Materials sampling and testing technicians work in laboratory, field, and plant site settings that present a wide range of occupational hazards. These hazards may include exposure to hazardous chemicals, airborne particulates, radioactive substances, hot materials, heavy equipment, live traffic, moving plant components, and specialized testing equipment. While safety information is available through product labels, safety data sheets, company policies, agency procedures, and some standards, the information is inconsistent and not always widely available to all workers.

There is currently no standard practice or guide specifically tailored to the transportation materials sampling and testing industry. Many standard practices and test methods state that they do not address all safety concerns and that users are responsible for establishing appropriate safety and health practices. However, safety guidance for some sampling and testing technicians may not exist in a consistent or accessible form. A comprehensive guide would help define and clarify relevant safety requirements, relate existing industry safety practices to transportation materials sampling and testing, and provide a baseline standard that can be applied across state departments of transportation, other public agencies, consulting firms, materials producers, and contractors.

OBJECTIVE: The objective of this research is to develop draft language for a comprehensive safety guide for consideration by the AASHTO Committee on Materials and Pavements (COMP) to help mitigate the risk of harm to materials sampling and testing technicians from occupational hazards. The guide should combine existing safety practices across many industries, guides, and documents and relate them to transportation materials sampling and testing processes. The guide should include recommended safety practices that can be used in laboratory, field, or plant site settings.

]]></description>
      <pubDate>Tue, 02 Jun 2026 15:00:57 GMT</pubDate>
      <guid>https://rip.trb.org/View/2709245</guid>
    </item>
    <item>
      <title>Low-Frequency High-Impact Travel for Data Analysis</title>
      <link>https://rip.trb.org/View/2709248</link>
      <description><![CDATA[Low-incidence travel behavior is difficult to capture in a traditional household travel study, where typically one to seven days of travel are collected from a representative sample of households. These behaviors may include travel modes used frequently by a small number of people (bicycling, carshare/vanpool), emerging modes not yet widely adopted (e-bikes, scooters, automated vehicles), complex household travel interactions, or infrequent behaviors such as rideshare use, long-distance travel, and trip replacement behavior such as home delivery of goods and services.

Because these behaviors occur infrequently, traditional survey methods often fail to collect enough observations for accurate estimation in travel demand models. A sufficient number of surveys—approximately 1,000 observations per market segment—is needed to support reliable analysis and forecasting. Despite their low incidence, many of these behaviors have significant impacts on transportation systems.

More than 40 state departments of transportation (DOTs) maintain statewide travel models that require accurate long-distance travel data to support costly intercity highway and rail investments. Emerging travel modes are also becoming critical policy issues in regional and statewide planning efforts.

The objective of this research is to identify and analyze methods for sampling people, households, and incidences of rare or emerging travel behaviors and determine how these methods can be incorporated into household travel survey data collection.]]></description>
      <pubDate>Tue, 02 Jun 2026 13:56:50 GMT</pubDate>
      <guid>https://rip.trb.org/View/2709248</guid>
    </item>
    <item>
      <title>Modernizing NDOT's Pavement Marking Program for Retroreflectivity Compliance and Cost-Effective Restriping </title>
      <link>https://rip.trb.org/View/2689409</link>
      <description><![CDATA[The evaluation of pavement marking materials primarily relies on their retroreflectivity, which is the measure of how effectively markings reflect vehicle headlight illumination back toward the driver. Deciding when pavement markings need to be restriped is not straightforward because their visibility depends on retroreflectivity. Nebraska Department of Transportation (NDOT) currently follows a pavement marking policy that is last updated over twenty years ago. The practice is based on fixed restriping frequencies (e.g., annually) determined by corridor type and traffic volume. The Federal Highway Administration (FHWA) requires all agencies to implement a pavement marking retroreflectivity maintenance method by September 6, 2026, and specifies minimum maintained retroreflectivity values of 50 mcd/m²/lx for roadways with posted speeds ≥ 35 mph and 100 mcd/m²/lx for speeds ≥ 70 mph. NDOT does not yet maintain a comprehensive or statewide pavement marking retroreflectivity dataset. Without historical measurements or geographically representative data, it cannot characterize how different marking materials deteriorate across Nebraska’s diverse traffic and climate conditions. This lack of data limits NDOT’s ability to transition from a frequency-based to a performance-based maintenance strategy that meets FHWA requirements, manages costs, and improves operational efficiency. The overall goal of this research project is to provide NDOT with a documented, MUTCD-compliant, and data-driven method for maintaining pavement marking retroreflectivity that ensures safety, regulatory compliance, and cost-effective use of maintenance resources. To achieve this goal, the project will pursue the following specific objectives: develop a Nebraska-specific hybrid maintenance method, develop a statistically sound statewide data-collection plan, develop and calibrate degradation models, and quantify expected life-cycle benefits.]]></description>
      <pubDate>Tue, 02 Jun 2026 12:26:55 GMT</pubDate>
      <guid>https://rip.trb.org/View/2689409</guid>
    </item>
    <item>
      <title>Evaluation of Alternative Intersection and Interchange Options for Nebraska </title>
      <link>https://rip.trb.org/View/2689408</link>
      <description><![CDATA[The Nebraska Department of Transportation (NDOT) has implemented and developed guidance for a limited set of unconventional designs (e.g., certain RCUTs and diverging diamond interchanges) and has accumulated experience through selected projects and research studies. NDOT lacks robust, Nebraska-specific tools to: (1) screen and select candidate unconventional facilities; (2) quantify trade-offs in operations, safety, and cost; and (3) develop practical guidelines that can be directly used by designers, planners, and district staff. This gap creates uncertainty when considering unconventional options and may limit NDOT’s ability to fully leverage designs that could offer meaningful safety and mobility benefits. The proposed research will provide NDOT with a structured and evidence-based approach for identifying the most suitable unconventional intersection and interchange options for Nebraska. By evaluating both the designs already implemented within the state and additional alternatives that may be considered soon, the study will broaden NDOT’s understanding of how various unconventional treatments perform under different traffic, geometric, and environmental conditions in Nebraska.]]></description>
      <pubDate>Tue, 02 Jun 2026 12:26:34 GMT</pubDate>
      <guid>https://rip.trb.org/View/2689408</guid>
    </item>
    <item>
      <title>High-Strength, Corrosion-Resistant Reinforcement for Empirical Deck Design </title>
      <link>https://rip.trb.org/View/2689407</link>
      <description><![CDATA[The Nebraska Department of Transportation (NDOT) seeks to maximize the long-term durability and minimize the lifecycle maintenance costs of the bridge deck for an upcoming major river-crossing replacement, where future deck rehabilitation or replacement would be exceptionally costly, disruptive, and hazardous. Although NDOT has adopted guidance intended to improve deck durability, current practices still rely primarily on empirical deck design provisions developed decades ago using Grade 60 reinforcing steel. These provisions specify total reinforcing area but do not require explicit evaluation of crack control parameters, do not account for the use of higher-strength reinforcing (e.g., Grade 80 or Grade 100), and do not provide direction on how reduced steel area enabled by higher yield strength may affect crack formation, crack widths, or long-term durability. At the same time, while recent European research has proposed durability-focused design approaches that incorporate explicit crack-width considerations, there remains significant disagreement within the research and practitioner communities regarding the extent to which crack width directly correlates with reinforced concrete durability. As a result, it is not yet clear whether or how such approaches should be adopted by NDOT; however, a thorough review and synthesis of this work is essential to inform any future deck reinforcement guidelines. As NDOT considers transitioning to higher-grade reinforcement to reduce material quantities and construction complexity, it currently has no validated methodology to configure bar size, spacing, and reinforcement ratios to ensure adequate crack control, residual crack behavior, and ultimate strength performance. ]]></description>
      <pubDate>Tue, 02 Jun 2026 12:26:14 GMT</pubDate>
      <guid>https://rip.trb.org/View/2689407</guid>
    </item>
    <item>
      <title>Implementation of Ultra-High-Performance Concrete (UHPC) Bridge Deck Overlays in Nebraska</title>
      <link>https://rip.trb.org/View/2689406</link>
      <description><![CDATA[The Nebraska Department of Transportation (NDOT) Project SPR-FY24(034) confirmed the superior mechanical and durability performance of Nebraska’s non-proprietary ultra high performance concrete (UHPC) mixtures, field implementation remains a critical missing step. Bridge deck overlays require substantially larger material volumes and longer placement durations than typical UHPC applications, such as joint connections or patch repairs. These factors introduce challenges in production logistics, equipment capacity, and quality control that must be validated under real construction conditions. Currently, NDOT and local contractors lack documented field procedures and specifications tailored to Nebraska’s climate, materials, and construction practices. Key uncertainties remain regarding surface preparation methods (e.g., milling versus hydrodemolition), on-site batching and mixing of large quantity using truck mixers, placement sequencing, construction joints, finishing, curing, and early-age strength verification. Without full-scale field demonstration and training, these unknowns limit NDOT’s ability to specify UHPC overlays in new or rehabilitation bridge projects. ]]></description>
      <pubDate>Tue, 02 Jun 2026 12:25:59 GMT</pubDate>
      <guid>https://rip.trb.org/View/2689406</guid>
    </item>
    <item>
      <title>Development and Evaluation of Approach Guardrail Transition with Increased Span Length between Concrete bridge Rail and First Transition Post - Phase II </title>
      <link>https://rip.trb.org/View/2689395</link>
      <description><![CDATA[Phase I of this project, funded by the Nebraska Department of Transportation (NDOT), addressed this need at the concept and simulation level. Midwest Roadside Safety Facility (MwRSF) researchers developed and refined several long-span approach guardrail transition (AGT) concepts for the 34-inch tall NDOT thrie-beam system and used LS-DYNA simulations to evaluate their performance with increased span between the concrete buttress and the first transition post under MASH TL-3 impact conditions. The work included evaluation of the upstream W-beam to thrie-beam transition, the downstream thrie-beam to rigid buttress connection, and identification of critical impact points for both the pickup truck and small car tests. These analyses demonstrated that the selected long-span concept is a promising candidate, but they do not satisfy Federal Highway Administration (FHWA) requirements. Federal acceptance of new roadside safety hardware under the American Association of State Highway and Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH) requires full-scale crash testing. An FHWA eligibility letter cannot be obtained on the basis of simulations alone. Without full-scale crash testing, the long-span AGT system cannot be fully validated, adopted statewide, or included in NDOT standard plans. Phase II is therefore needed to conduct the required full-scale MASH TL-3 crash tests and provide an FHWA-compliant evaluation of the new long-span AGT system.]]></description>
      <pubDate>Tue, 02 Jun 2026 12:25:41 GMT</pubDate>
      <guid>https://rip.trb.org/View/2689395</guid>
    </item>
    <item>
      <title>Nebraska Risk-Informed Construction Scheduling and Impact Analysis</title>
      <link>https://rip.trb.org/View/2689393</link>
      <description><![CDATA[Assigning a reasonable contract time is central to the Nebraska Department of Transportation (NDOT)’s project delivery process. The number of working days directly affects bid prices, contractor time-related overhead, public traffic impacts, and NDOT’s construction-engineering workload. However, many NDOT projects experience time extensions or schedule adjustments. These delays often arise from weather windows, utility coordination challenges, labor or material availability issues, and unforeseen field conditions. The presence of these uncertainties means that a single deterministic duration for each activity does not adequately represent the true likelihood of early or late project completion. NDOT currently relies on deterministic schedules and historical judgment when assigning contract time. These methods assume fixed activity durations and do not fully capture the uncertainties caused by weather, utilities, material supply, labor availability, or construction sequencing constraints. As a result, some projects may receive either more contract days than needed or face unexpected time extensions that increase cost and user delay. Recent research and best practices from other state DOTs and the Federal Highway Administration (FHWA) emphasize the need for probability-based scheduling that uses production-rate data, activity dependencies, and delay risk to estimate a realistic range of completion dates. The overarching goal of this project is to develop a data-driven, probability-based scheduling tool that enables NDOT to determine reasonable contract time and proactively assess construction delay risks throughout the project lifecycle.]]></description>
      <pubDate>Tue, 02 Jun 2026 12:25:19 GMT</pubDate>
      <guid>https://rip.trb.org/View/2689393</guid>
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