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    <title>Research in Progress (RIP)</title>
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    <atom:link href="https://rip.trb.org/Record/RSS?s=PHNlYXJjaD48cGFyYW1zPjxwYXJhbSBuYW1lPSJzdWJqZWN0aWQiIHZhbHVlPSIxODAwIiAvPjxwYXJhbSBuYW1lPSJkYXRlaW4iIHZhbHVlPSI3MzAiIC8+PHBhcmFtIG5hbWU9InN1YmplY3Rsb2dpYyIgdmFsdWU9Im9yIiAvPjxwYXJhbSBuYW1lPSJ0ZXJtc2xvZ2ljIiB2YWx1ZT0ib3IiIC8+PHBhcmFtIG5hbWU9ImxvY2F0aW9uIiB2YWx1ZT0iMTYiIC8+PC9wYXJhbXM+PGZpbHRlcnMgLz48cmFuZ2VzIC8+PHNvcnRzPjxzb3J0IGZpZWxkPSJwdWJsaXNoZWQiIG9yZGVyPSJkZXNjIiAvPjwvc29ydHM+PHBlcnNpc3RzPjxwZXJzaXN0IG5hbWU9InJhbmdldHlwZSIgdmFsdWU9InB1Ymxpc2hlZGRhdGUiIC8+PC9wZXJzaXN0cz48L3NlYXJjaD4=" rel="self" type="application/rss+xml" />
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    <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>
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    <item>
      <title>Conduct 1D and 2D Hydraulic Modeling of Traffic Rail for Design of TxDOT Bridges and Culverts</title>
      <link>https://rip.trb.org/View/2768431</link>
      <description><![CDATA[Researchers will develop a method to quantify hydraulic performance of different bridge and traffic rail types for implementation in 1D and 2D hydraulic modeling software to determine impacts on the surrounding floodplain during extreme flood events. The use of a previously developed rail rating curve and submergence model, combined with additional physical testing for newer rail types, will be incorporated into floodplain mapping software such as Hydrologic Engineering Center River Analysis Software (HEC-RAS) (1D and 2D) and culvert design software such as Hydraulic 8 Culvert hydraulics Analysis Program (HY-8). Researchers will develop generalizable modeling methodologies and guidance for various rail configurations under both 1D and 2D hydraulic modeling conditions to inform how to model different systems effectively and consistently.]]></description>
      <pubDate>Fri, 28 Aug 2026 10:01:58 GMT</pubDate>
      <guid>https://rip.trb.org/View/2768431</guid>
    </item>
    <item>
      <title>Synthesis: Flood Early Warning Systems in Texas and the United States</title>
      <link>https://rip.trb.org/View/2768432</link>
      <description><![CDATA[The research team will synthesize Flood Early Warning Systems (FEWS) deployed across Texas and the United States, focusing on systems applicable to State Departments of Transportation (DOTs). Researchers will evaluate automated gates, flashing beacons, rainfall sensors, and stream gauges, and will assess their performance during documented flood events. The research team incorporate guidance from the Texas Water Development Board (TWDB), the 2024 State Flood Plan, and local initiatives including the City of Austin beacon systems and the Houston TranStar network, and will benchmark practices from comparable states.]]></description>
      <pubDate>Fri, 28 Aug 2026 10:01:47 GMT</pubDate>
      <guid>https://rip.trb.org/View/2768432</guid>
    </item>
    <item>
      <title>Synthesis: Techniques for Freeboard and Other Simplified Approaches to Account for Uncertainty</title>
      <link>https://rip.trb.org/View/2768669</link>
      <description><![CDATA[Freeboard is widely considered as the vertical clearance above a design water-surface elevation to reduce bridge and culvert vulnerability to flood-related hazards; however, current guidance across agencies on freeboard is inconsistent and often lacks transparent treatment of hydrologic, hydraulic, and debris-related uncertainty. Texas Department of Transportation (TxDOT) Hydraulic Design Manual does not specify a recommended freeboard value, which creates challenges for consistent and defensible design decisions. The research team will conduct a structured synthesis of national- and state-level guidance, tools, and research related to freeboard determination for bridges and culverts and other simplified approaches for addressing uncertainty. Where directly relevant and readily comparable, selected international guidance will be included as supplemental examples to provide additional context. Researchers will systematically review authoritative design manuals, federal guidance, DOT practices in different states, and prior research to document how freeboard is defined, justified, and applied, including consideration of design events, structure types, technical rationale, uncertainty treatment, and any exception procedures. The research team will develop traceable synthesis products, including annotated catalogs, evidence matrices, and cross-agency comparison tables, to clearly summarize current practice and identify areas of inconsistency or ambiguity. The primary outcome will be a set of synthesis materials organized for direct use by TxDOT to support consistent, transparent, and risk-aware freeboard determination and to inform future updates to TxDOT’s hydraulic guidance. ]]></description>
      <pubDate>Fri, 28 Aug 2026 10:01:35 GMT</pubDate>
      <guid>https://rip.trb.org/View/2768669</guid>
    </item>
    <item>
      <title>Investigating the Structural Impact of Delamination in Precast Concrete Panel Decks</title>
      <link>https://rip.trb.org/View/2768424</link>
      <description><![CDATA[Precast concrete panel (PCP) deck systems are the primary method for bridge deck construction in Texas. While these systems are designed to act compositely with a cast-in-place (CIP) concrete topping, recent field inspections and Ground Penetrating Radar (GPR) evaluations have identified widespread delamination at the PCP-CIP concrete interface. This bond degradation challenges the fundamental design assumption of monolithic behavior, which may lead to issues such as compromised punching shear capacity, reduced rigidity, increased deflection, water penetration, and potentially shortened service life. But the Texas Department of Transportation (TxDOT) currently lacks the data-driven, quantitative criteria necessary to evaluate the structural and serviceability implications of such distress. This research project addresses this critical knowledge gap by investigating how varying extents of delamination influence the bridge deck's serviceability, load-carrying capacity, fatigue resistance, and overall durability.]]></description>
      <pubDate>Thu, 27 Aug 2026 11:21:14 GMT</pubDate>
      <guid>https://rip.trb.org/View/2768424</guid>
    </item>
    <item>
      <title>Impact of Flooding on Pavement Drawdown Structures</title>
      <link>https://rip.trb.org/View/2767321</link>
      <description><![CDATA[Upon completion, this study will provide Iowa counties and the Iowa Department of Transportation (Iowa DOT) with a robust framework to assess and manage flood risks across Iowa's transportation infrastructure used as drawdown structures, offering several key benefits: enhanced flood risk management, cost savings, improved resilience, and strategic planning tools.
The framework will enable precise evaluations of infrastructure (drawdown structures) vulnerability, allowing Iowa Counties and Iowa DOT to prioritize maintenance and allocate resources efficiently. By predicting the loss of service life under various flood scenarios,Iowa counties and Iowa DOT can implement targeted countermeasures, reducing emergency repairs.
The ability to predict and mitigate flood-induced damage will result in cost savings, extend infrastructure service life, and minimize maintenance costs. The study’s focus on practical, cost-effective solutions will help optimize counties investments and enhance network resilience.
Adopting recommended countermeasures will improve infrastructure’s capacity to withstand increasingly frequent and severe floods, safeguarding roads while ensuring public safety and reliability.]]></description>
      <pubDate>Mon, 24 Aug 2026 13:11:53 GMT</pubDate>
      <guid>https://rip.trb.org/View/2767321</guid>
    </item>
    <item>
      <title>Modernization of Idaho StreamStats: Updates to Statewide Basin Characteristics and At-Site Peak Streamflow Statistics</title>
      <link>https://rip.trb.org/View/2742769</link>
      <description><![CDATA[The Idaho Transportation Department (ITD) is seeking to enhance the Idaho StreamStats application by incorporating updated basin characteristics, hydrography, and at-site peak streamflow statistics using current datasets, advanced geospatial technologies, and modern hydrologic analysis methods. StreamStats is an important tool used by transportation engineers, planners, and water resource professionals to estimate streamflow characteristics that support the design and maintenance of bridges, culverts, drainage infrastructure, and other transportation assets. This project will leverage high-resolution lidar-derived elevation data, updated land cover and climate datasets, improved hydrography, and current flood-frequency analysis methods to strengthen the accuracy, consistency, and reliability of hydrologic information available through StreamStats. Research activities will include updating basin characteristics, recalculating peak-flow statistics using recent streamflow records, integrating updated information into the StreamStats application, and publishing supporting datasets to promote transparency and future use. The resulting tools and workflows will provide ITD and its partners with enhanced hydrologic information to support infrastructure design, flood risk assessment, regulatory compliance, and long-term transportation planning.]]></description>
      <pubDate>Tue, 04 Aug 2026 16:20:38 GMT</pubDate>
      <guid>https://rip.trb.org/View/2742769</guid>
    </item>
    <item>
      <title>Physics Informed Neural Network (PINN) enabled Predictive Resilience Framework for Maritime and Multimodal Levee Infrastructure</title>
      <link>https://rip.trb.org/View/2732360</link>
      <description><![CDATA[The performance and resilience of levee systems are governed by complex
hydro-mechanical interactions influenced by transient seepage, soil stratification, and environmental loading.
Conventional monitoring approaches, while effective in capturing field conditions, lack predictive capability and
often fail to integrate subsurface characterization with real-time system response. This study proposes a Physics-Informed Neural Network (PINN) enabled predictive resilience framework for maritime and multimodal levee
infrastructure, integrating multi-source sensing, geophysical imaging, and physics-based modeling. The
framework leverages Internet of Things (IoT) based sensor networks, including IMU derived tilt and displacement measurements, and
environmental variables such as rainfall, temperature, and soil moisture. To enhance subsurface characterization,
Electrical Resistivity Imaging (ERI) and Multichannel Analysis of Surface Waves (MASW) are incorporated to
capture spatial variability in moisture distribution, stiffness profiles, and potential seepage zones. These datasets
are fused with UAV based LiDAR point cloud models to develop high-resolution, temporal geospatial conditional
representations of levee geometry and deformation. The integrated dataset is utilized to calibrate finite element
method (FEM) based seepage and stability models, enabling accurate representation of coupled hydromechanical
behavior. The PINN architecture embeds governing equations of transient flow and unsaturated soil
mechanics into the learning process, allowing physically consistent prediction of pore pressure, volumetric
moisture content, and deformation fields. A hybrid physics-guided, data-driven digital twin will be developed to
continuously assimilate field and geophysical data, providing real-time predictions and identifying anomaly
thresholds indicative of instability. The proposed framework advances geotechnical asset management by
enabling predictive failure assessment, risk-informed decision-making, and proactive maintenance strategies,
thereby enhancing the resilience of critical maritime and multimodal infrastructure systems under extreme
environmental conditions.]]></description>
      <pubDate>Tue, 21 Jul 2026 16:41:56 GMT</pubDate>
      <guid>https://rip.trb.org/View/2732360</guid>
    </item>
    <item>
      <title> Evaluate PVC Water Main Materials in Roadway Projects</title>
      <link>https://rip.trb.org/View/2731924</link>
      <description><![CDATA[Water main breaks within Michigan Department of Transportation (MDOT) R.O.W. pose significant risks to the Department and stakeholders, including complete road
closures, detours, as well as boil water advisories. MDOT is obligated to replace municipal water mains that are impacted by
Road and Bridge projects, typically at Project costs. The Department currently only specifies ductile iron water main (DIWM)
materials within the influence of its roadways. Rising costs of and supply issues with DIWM in recent years have caused
significant project delays. Municipalities are increasingly requesting the use of PVC water main materials within MDOT R.O.W.
to maintain material continuity of their facilities. Allowing use of alternative materials could reduce costs and/or delays to the
Department. MDOT needs data to address Municipal Engineers and Industry questions on the suitability of allowing PVC water
main on MDOT projects. Several factors must be evaluated in comparison to DIWM; the durability and expected design life,
historical leakage and breakage rates, cause of failures, the long-term safety of PVC water main materials on public health,
and life cycle costs. The research must provide data guidance and recommendations on the advantages and disadvantages of
PVC versus DIWM to allow consideration of a change to current policy.]]></description>
      <pubDate>Fri, 17 Jul 2026 14:29:12 GMT</pubDate>
      <guid>https://rip.trb.org/View/2731924</guid>
    </item>
    <item>
      <title>Leveraging Existing Vegetated Roadside Areas for Efficient Stormwater Management</title>
      <link>https://rip.trb.org/View/2726138</link>
      <description><![CDATA[Stormwater runoff from transportation infrastructure presents a persistent challenge for Oregon’s transportation system due to the requirement to treat highway stormwater runoff and protect downstream water quality. Current regulatory requirements compel project teams to demonstrate adequate stormwater treatment and infiltration performance during planning and design. However, limited understanding of how hydrologic data and roadside soil properties influence geochemical treatment capacity often prevents reliable evaluation of whether the natural roadside environment itself can meet objectives, providing an unrealized opportunity for potential savings on unnecessary facility installation and maintenance costs.
OBJECTIVES: The overall objective of this project is to develop and validate an integrated hydrologic-geochemical decision-support tool that enables early-stage screening of existing roadside stormwater infiltration potential and treatment performance. The tool will provide Oregon Department of Transportation (ODOT) with simulation capabilities to predict and quantify surface runoff routing, infiltration capacity, and subsurface geochemical dynamics. The coupled hydrologic-geochemical framework will support quantitative evaluation of whether already existing roadside environments can meet stormwater performance metrics and identify locations where built treatment facilities are actually necessary. 
The project will provide ODOT with quantitative decision-support framework for early-stage screening of roadside stormwater infiltration and treatment feasibility. The framework directly addresses the current uncertainty in determining when existing roadside soils and vegetative cover can meet stormwater performance requirements and when engineered treatment facilities are necessary. By enabling systematic identification of locations where existing soils provide sufficient infiltration and contaminant attenuation, this project may assist with (1) reducing unnecessary engineered stormwater treatment facilities that require construction costs, operational costs and long-term maintenance commitments, and (2) reducing the need to acquire additional ROW to install engineered facilities, minimizing both project delivery and O&M costs. Even if additional ROW may be needed to fit the natural areas for treatment, long-term operation and maintenance costs will likely be reduced.]]></description>
      <pubDate>Wed, 08 Jul 2026 17:25:51 GMT</pubDate>
      <guid>https://rip.trb.org/View/2726138</guid>
    </item>
    <item>
      <title>Updating Streamflow Statistics for Central and Eastern Oregon to Reduce Flooding Risk</title>
      <link>https://rip.trb.org/View/2724818</link>
      <description><![CDATA[Regional flood frequency equations are needed to plan, maintain, and protect critical infrastructure against flood risks across Oregon. When designing and maintaining hydraulic infrastructure in central and eastern Oregon, Oregon Department of Transportation
(ODOT) professionals face persistent challenges of sparse streamflow data, highly variable precipitation, diverse geologic and topographic features, and irregularities due to large water withdrawals for agriculture. While reliable streamflow statistics can be obtained for western Oregon locations using the ODOT funded U.S. Geological Survey (USGS) StreamStats tool, the current accuracy of the underlying regression equations for locations in central and eastern Oregon are much less reliable, and in some cases not available. Further, though the StreamStats tool may be helpful for some central and eastern Oregon locations, these regression equations—now more than 20 years old—may not accurately reflect present-day conditions, particularly where basins have experienced significant shifts in long-term precipitation and temperature patterns, land use, or water withdrawals. Accurate streamflow statistics are essential for sizing bridges, culverts, and roadside drainage, ensuring infrastructure longevity through variable flow conditions and extreme weather events.
The objective of this research is to update Oregon streamflow statistics and the heavily used StreamStats tool so that this tool can be relied upon for ODOT hydraulic design in central and eastern Oregon. This update process will employ new machine-learning and refined statistical approaches, together with more expansive data from states that share central and eastern Oregon’s hydraulic and hydrologic characteristics. Specifically, this research aims to: (1) enhance design accuracy, (2) support infrastructure longevity under future conditions, (3) optimize resource allocation, (4) improve planning and reduce maintenance, and (5) facilitate regulatory compliance and environmental stewardship with effective fish passage design and habitat protection.]]></description>
      <pubDate>Wed, 08 Jul 2026 12:19:06 GMT</pubDate>
      <guid>https://rip.trb.org/View/2724818</guid>
    </item>
    <item>
      <title>Improving Stormwater Systems for Debris and Contaminant Capture</title>
      <link>https://rip.trb.org/View/2712206</link>
      <description><![CDATA[Highway runoff carries a complex mix of pollutants, including debris, heavy metals, and nutrients. Oil, grease, and combustion byproducts from vehicles further add to the contaminant load. In addition to these conventional pollutants, scientific advances have highlighted contaminants of emerging concern (CECs) that were not fully recognized when most departments of transportation’s (DOT’s) stormwater programs were first developed.

Unlike conventional pollutants that degrade over time, many of these debris and CECs persist. They clog inlets and ponds, reduce hydraulic conductivity, and increase pollutant loads to downstream waters. For DOTs, this creates two major challenges: rising costs to maintain stormwater assets, and regulatory risk under municipal separate storm sewer system permits if pollutant control cannot be demonstrated.

The objective of this research is to develop a guide for reducing broad pollutants, which include macro-debris, microplastics, and tire wear particles, which have been demonstrated to contain compounds toxic to certain aquatic organisms.]]></description>
      <pubDate>Wed, 10 Jun 2026 11:28:41 GMT</pubDate>
      <guid>https://rip.trb.org/View/2712206</guid>
    </item>
    <item>
      <title>Develop a Risk-Based Framework for Selecting Hydrologic, Hydraulic, and Scour Criteria for Temporary Hydraulic Structures and Encroachments</title>
      <link>https://rip.trb.org/View/2712198</link>
      <description><![CDATA[Temporary hydraulic structures, such as bridges, culverts, and temporary access fills, are widely used during construction and emergency response to maintain transportation access and restore mobility following infrastructure damage. Unlike permanent structures, these installations are often designed for shorter service lives and may not meet the same hydrologic and hydraulic criteria. However, current design practices vary significantly across state departments of transportation, with no consistent national guidance for determining appropriate risk levels or design storm frequencies.

 Recent studies indicate that many agencies rely on case-by-case assessments, qualitative risk evaluations, or inconsistent application of evaluation criteria for temporary structures. Additionally, there is limited use of quantitative risk models and little integration of factors such as traffic impacts, environmental considerations, and failure consequences. The lack of standardized guidance can result in designs potentially contributing to increased conservatism and lifecycle costs, or to reduced system resilience and increased risk in some scenarios. Research is needed to identify and incorporate factors such as costs, structure lifespan, traffic, scour conditions, environmental impacts, failure risks, and regional variability to help determine how to select hydrologic, hydraulic, and scour criterion for temporary structures and to measure performance.

The objectives of this research are to develop (1) a practitioner’s guide and a data-driven risk-based decision-making framework for selecting hydrologic, hydraulic, and scour design criteria for temporary hydraulic structures and encroachments; and (2) a standalone memorandum with language suitable for AASHTO’s consideration in evaluating potential updates to the AASHTO Drainage Manual.]]></description>
      <pubDate>Tue, 09 Jun 2026 17:42:06 GMT</pubDate>
      <guid>https://rip.trb.org/View/2712198</guid>
    </item>
    <item>
      <title>Design of Stormwater BMPs for Surface and Groundwater Protection Based on Site-Scale Soil Properties: Phase II</title>
      <link>https://rip.trb.org/View/2706364</link>
      <description><![CDATA[The objective of this project is to optimize the nitrogen (N) and phosphorus (P) removal potential of stormwater basins by improving the ability to predict the performance of common native soil properties alone, or with a BAM amendment, and using two planting specifications typically utilized in Florida Department of Transportation (FDOT) maintenance. Phase II will build upon the findings of Design of Stormwater BMPs for Surface and Groundwater Protection Based on Site-Scale Soil Properties: Phase I BDV24-977-43 (hereafter referred to as “Phase I”), which demonstrated the superior performance of unamended native soils with moderate soil organic matter and clay contents in the removal and sequestration of N and P during short-term laboratory experiments. Specifically, the research team will leverage this knowledge in a new experiment with improved external validity through the use of outdoor mesocosms in a multi-year study (e.g., scaling-up in both space and time). Commonly encountered native Florida soils will be prepared and planted per FDOT specification in replicated stock tanks (e.g., ~300-500 gal), with or without a BAM blanket filter, and using at least two FDOT approved vegetative strategies. Inflow and outflow hydrology will be controlled to mimic wet and dry basin hydropatterns and real-time mass balance of nutrient transport/transformation. The plant-soil-microbial interactions will be investigated to determine optimal N and P removal rates under varied hydrology. This new empirical data will improve stormwater BMPs by more accurately assessing the potential of native site soils, planting, and amendment strategies to function in nutrient remediation at the project site scale.]]></description>
      <pubDate>Wed, 27 May 2026 10:39:28 GMT</pubDate>
      <guid>https://rip.trb.org/View/2706364</guid>
    </item>
    <item>
      <title>In-Stream Vegetation for Scour Control at High-Proximity Bridge Crossing Elements</title>
      <link>https://rip.trb.org/View/2706037</link>
      <description><![CDATA[Scour and erosion are leading causes of bridge failure in North America and present significant safety and maintenance challenges, particularly at crossings where piers, abutments, and channel banks are in close proximity. Existing scour countermeasures are often costly, difficult to implement under complex hydraulic conditions, and require ongoing maintenance. Although aquatic vegetation has been observed to alter approach flow patterns in ways that may reduce local scour, a rigorous scientific basis for its use as a scour-control strategy at bridge crossings is not currently available.
This project employs detailed physical modeling to evaluate the effectiveness of in-stream vegetation for scour control at high-proximity bridge crossings. Experiments will be conducted in a high-gradient tilting flume with an erodible sediment bed, using particle image velocimetry and laser-based bathymetric scanning to measure velocity fields, turbulence characteristics, shear stresses, and resulting scour patterns. The research will quantify how vegetation patches influence local flow structure and sediment transport near piers, abutments, and banks. The results will form the foundation of a knowledge base supporting development of practical implementation guidelines.
]]></description>
      <pubDate>Sat, 23 May 2026 18:04:47 GMT</pubDate>
      <guid>https://rip.trb.org/View/2706037</guid>
    </item>
    <item>
      <title>Development of design guidelines for protection against erosion at bridge piers of rectangular cross section and estimating effects of pressurized flow on erosion potential</title>
      <link>https://rip.trb.org/View/2706034</link>
      <description><![CDATA[Bridge piers are vulnerable to severe erosion (scour) during high-flow and flooding conditions, which can compromise structural stability and, in extreme cases, lead to bridge failure. Existing riprap design methodologies used to protect bridge piers have limitations, particularly for rectangular piers and for conditions in which bridge decks become submerged and flow transitions from open channel to pressurized regimes. Inadequate riprap sizing under such conditions increases risk of structural distress, traffic interruption, and potential safety hazards.
This project develops improved design guidelines for riprap protection at rectangular bridge piers under both open channel and pressurized flow conditions. Using validated three-dimensional numerical simulations, the research will quantify how pier geometry, aspect ratio, angle of attack, and flow regime influence critical shear stress and the Froude number associated with stone failure. The project will propose a multi-parameter riprap sizing formula applicable to a broader range of geometrical and hydraulic conditions, including overtopping scenarios. Recommendations will be provided for adapting existing HEC-18 methodologies to account for pressurized flow conditions at bridge sites.

]]></description>
      <pubDate>Sat, 23 May 2026 17:39:45 GMT</pubDate>
      <guid>https://rip.trb.org/View/2706034</guid>
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