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    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
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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>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>Dynamic dilemma zone at signalized intersection: Attention allocation patterns using cure survival analysis for male riders</title>
      <link>https://trid.trb.org/View/2655851</link>
      <description><![CDATA[The design of the signal at the intersection considers the constant speed of the riders and the dilemma zone to be static. However, these assumptions may not hold true in complex environments with multiple users. This study explores the dynamic dilemma zone by incorporating the time to detect the signal by analyzing the drivers’ eye gaze movements and attention allocation patterns. The delay in detecting the amber phase of the signal can put drivers in a situation where they can neither safely cross the intersection nor stop before the stop line. The experiments were conducted in a virtual environment with 105 participants predominantly considering male riders. The image processing algorithms identified the first instance of riders noticing the amber phase. The parametric cure survival models were used to quantify the time to detect the signal as they incorporate the fact that some drivers may not look at the signal for the entire duration. This study further considered the complex decision-making of speeding and decelerating at the onset of amber phase at signalized intersections. The riders’ choices to vary the speed and safely or unsafely crossing the signal were quantified across psychological constraints. The results revealed that the odds of unsafe crossing at signal increased by 3.3, even in situations where riders were talking to pillion riders. The results indicated that riders under time pressure were more focused on the road, and their time to detect the signal was 0.72 s more than the base conditions.]]></description>
      <pubDate>Wed, 04 Feb 2026 17:05:20 GMT</pubDate>
      <guid>https://trid.trb.org/View/2655851</guid>
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    <item>
      <title>Nearshore wave breaking limit for gentle bottom slopes</title>
      <link>https://trid.trb.org/View/2649708</link>
      <description><![CDATA[The relative wave height (RW=H/d, H is wave height and d is water depth) threshold is a critical parameter for coastal engineering. Field observations from the Yellow River Delta, however, recorded RW approaching 1 under extreme conditions, significantly exceeding the standard 0.78 threshold and suggesting a potential limitation of laboratory-derived standards. This study analyzed 16,624 in-situ measurements to propose a limit for RW[subscript max]-seabed slope (i) relationship (RW[subscript max]=0.55+0.4212×exp(−0.00038/i)) applicable to slopes <1/200. While both this study and Nelson (1983) reported an asymptotic RW of 0.55 for very mild slopes, this study identified a markedly milder transition slope (0.00009, compared with 0.0012 in Nelson (1983)). The accurate prediction of this limit under large-wave conditions was of particular engineering significance. The revised limit offered a 31.8 % more reliable estimate for large waves (height >5 m) in intermediate depths (RD < 0.2) compared to 0.78 threshold. These waves (height >5 m) had 2 years return period according to extreme wave analysis in shallow waters, therefore may be frequently encountered during the project life. In addition, analysis results showed that waves broke in shallower depths than those estimated by existing limits. This finding was potentially applicable to over 85 % of global nearshore areas where the bottom slope was less than 1/200. Therefore, the new breaking limit is applicable for major coastal engineering projects.]]></description>
      <pubDate>Mon, 02 Feb 2026 09:31:32 GMT</pubDate>
      <guid>https://trid.trb.org/View/2649708</guid>
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    <item>
      <title>Time series analysis of resampled red-light violations to understand drivers’ adaptation to extended yellow intervals</title>
      <link>https://trid.trb.org/View/2630692</link>
      <description><![CDATA[Red-light running (RLR) poses significant safety risks at signalized intersections, often leading to severe crashes. Increasing yellow intervals has been proposed as a countermeasure for RLR violations. Despite the immediate effectiveness of increasing yellow intervals in reducing RLR violations, concerns remain regarding potential driver adaptation over time. This study aimed to evaluate the long-term effectiveness of increased yellow intervals on driver compliance using RLR events on through and left-turn movements.   The data were collected from three intersections in the Phoenix metropolitan area for 81 and 496 days (about one and a half years) before and after increasing the through and left-turn yellow intervals. An Interrupted Time Series Analysis (ITSA) and Block Bootstrap Resampling were applied to determine the significance of the intervention and the impact of the intervention through time.   The results showed that increasing the yellow intervals led to a significant and sustained reduction in RLR violations for both through and left-turn movements across all treatment sites. Importantly, ITSA results indicated no evidence of driver adaptation, reinforcing the long-term effectiveness of increasing yellow intervals on RLR. This research also shows the impact of movement types and site-specific characteristics, including traffic volume and intersection layout, on the effectiveness of signal timing adjustments for safety improvements.   Understanding the drivers’ adaptation to the changes in signal timing could assist agencies when considering using longer yellow intervals to address chronic red light running violations and defining the allowable period before readjustment of signal timing plans for safety purposes.]]></description>
      <pubDate>Tue, 23 Dec 2025 09:29:09 GMT</pubDate>
      <guid>https://trid.trb.org/View/2630692</guid>
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      <title>Guidebook on Determining Yellow and Red Intervals to Improve Signal Timing Plans for Left-Turn Movements</title>
      <link>https://trid.trb.org/View/2582254</link>
      <description><![CDATA[The objective of this research is to develop and test a comprehensive framework for setting yellow change and red clearance intervals for the left-turn movement, which can be used directly by the field traffic engineers in Texas. This guidebook provides a general description of the procedures entailed in this framework.]]></description>
      <pubDate>Sat, 22 Nov 2025 17:17:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/2582254</guid>
    </item>
    <item>
      <title>Acoustic Emission Monitoring and Localization Method for Broken Wires in 13 In-Service Stay Cables Connected by a 165-m-Long Waveguide Rod</title>
      <link>https://trid.trb.org/View/2611167</link>
      <description><![CDATA[The stay cable is one of the crucial structures of a cable-stayed bridge, and the occurrence of broken wires in cables may endanger the safety of the entire bridge. Currently, the acoustic emission (AE) monitoring method for detecting broken wires of cables requires a significant number of sensors, which leads to high monitoring costs. To reduce the monitoring cost and the number of sensors for cable monitoring, this study used a 165-m-long waveguide rod to connect 13 cables on the Yellow River Super Bridge of Anluo Expressway in Henan Province, China, and carried out experiments on the acoustic emission attenuation of the waveguide rod and the arrangement of sensors. The acoustic emission attenuation law of rigid and flexible waveguide rods with a length of 165 m was studied, the difference in the AE sensor arrangement on the side and cross section of the waveguide rod was analyzed, and the arrangement of AE sensors was optimized. Two AE sensors were arranged at both ends of the waveguide rod to locate the cable with broken wires. The results indicate that the acoustic emission amplitude of the 165-m-long rigid waveguide rod is the characteristic parameter with the smallest attenuation compared with duration, ringing count, and energy. The attenuation of the acoustic emission amplitude of the 165-m-long flexible waveguide rod is greater than that of the rigid waveguide rod under the same length, while the attenuation rates of time duration, ringing count, and energy are less than those of the rigid waveguide rod. Under the comprehensive comparison, the two types of waveguide rods show lower attenuation in different characteristic parameters and are suitable for various application scenarios; therefore, one can reasonably choose the type of waveguide rods according to the actual structure of the cable, monitoring needs, and the installation environment. The AE sensor arranged on the cross section of the waveguide rod is more conducive to monitoring the broken wires of the cables. A 165-m-long waveguide rod is used to connect 13 cables, and a sensor arranged at both ends of the waveguide rod can determine cables with broken wires.]]></description>
      <pubDate>Wed, 19 Nov 2025 17:09:39 GMT</pubDate>
      <guid>https://trid.trb.org/View/2611167</guid>
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    <item>
      <title>Structural Response and Failure Analysis of a Suspension Pipeline Bridge Subjected to Typical Loads</title>
      <link>https://trid.trb.org/View/2567098</link>
      <description><![CDATA[In order to study the structural response and failure of suspension pipeline bridges under typical loads, the Yellow River suspension pipeline bridge is taken as the study object, the stiffness matrix under the coupling effect of geometric nonlinear factors is derived, the numerical simulation model and the health monitoring system are established, and the shape-finding calculation of the cable structure system is carried out. The numerical simulation model is validated by comparing simulation data with monitoring data. Through modal analysis, it is found that the Yellow River suspension pipeline bridge is a low-frequency vibration structure. On the basis of the above work, its structural responses under typical loads are quantified. The stress and displacement distribution laws of the cable structure system under snow loads are obtained. With the increase of snow load, the stress of the main cable, suspension cable, tower, and bridge truss increases, while the stress of the tie cable, wind cable, and stable cable decreases. At low wind speeds, the wind cable is more sensitive to wind loads, while at high wind speeds, the bridge truss is more sensitive to wind loads. Under the pigging load, the maximum displacement change occurs at 5/8 of the bridge truss, and this discovery helps to accurately protect the weak location under the water hammer action. When the pig passes through a certain point, the displacement at that point will show a downward turning point. Under the seismic load, the amplitude of the bridge truss, main cable, and wind cable is relatively large. And the positive displacement is much greater than the negative displacement. The displacement at 1/2 of the wind cable is less than the displacement at 1/4 of it, which indicates that the flexibility of the wind cable is maximum at its 1/4 position. Finally, the weak links and corresponding failure prevention measures of the Yellow River suspension pipeline bridge are determined, which can provide the reference for the daily maintenance, integrity management, reliability analysis, and optimization design of other suspension pipeline bridges.]]></description>
      <pubDate>Wed, 17 Sep 2025 10:56:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/2567098</guid>
    </item>
    <item>
      <title>Yellow and Red Intervals to Improve Signal Timing Plans for Left-Turn Movements</title>
      <link>https://trid.trb.org/View/2570926</link>
      <description><![CDATA[This project intends to develop and test a framework for setting yellow change and red clearance intervals for the left-turn movement, which can be used directly by the field traffic engineers in selecting the appropriate values for parameters in the proposed framework. The framework is designed to incorporate a comprehensive set of parameters related to intersection geometry, perception, human comfort, driver's behavior, safety issues, and traffic related laws. The application of this proposed framework is expected to improve both the left-turn movement safety and the efficiency at the intersection. This is the interim report for the project, which summarizes the work that has been performed during the first year (2001-2002) of this two-year project.]]></description>
      <pubDate>Mon, 01 Sep 2025 16:31:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/2570926</guid>
    </item>
    <item>
      <title>Field Evaluation of Pavement Marking Materials “Nontoxic Yellow Paint”</title>
      <link>https://trid.trb.org/View/2566962</link>
      <description><![CDATA[The Federal Highway Administration (FHWA) initiated a program to develop a lead-free yellow traffic paint. Two chlorinated rubber-alkyd-chlorinated paraffin yellow traffic paints were developed utilizing organic yellows. One of the paints, FHWA Code 49, exhibits a color very close to that achieved with medium chrome yellow. The other paint is similar in color to light chrome yellow and is designated FHWA Code 52. On November 3, 1979, FHWA entered into a contract with the Texas State Department of Highways and Public Transportation (SDHPT) to evaluate the two formulations and a 50/50 mix of SDHPT standard white and yellow traffic paint. The contract called for SDHPT standard yellow traffic paint to be used as a control. All of the traffic paints were to be evaluated on asphaltic concrete (ACP) and portland cement concrete (PCCP) pavements.]]></description>
      <pubDate>Tue, 08 Jul 2025 13:38:40 GMT</pubDate>
      <guid>https://trid.trb.org/View/2566962</guid>
    </item>
    <item>
      <title>Evaluation of Intersection Safety and Capacity Relevant to Signal Timing on Arizona’s State Highway System</title>
      <link>https://trid.trb.org/View/2550937</link>
      <description><![CDATA[Traffic signal phase-change intervals are intended to provide a safe transition between two conflicting signal phases or a right-of-way transition between conflicting road-user movements. As a result, signal phase change (includes yellow change interval, red-clearance interval, and pedestrian intervals) has significant safety and operations implications at signalized intersections. Currently, there is no national standard for calculating these durations. Additionally, the current ADOT-recommended practice for calculating traffic signal intervals has resulted in two issues: (1) lengthy red-clearance intervals at interchanges with large conflict areas; and (2) yellow change interval durations with the potential of not meeting the needs of the driver population. The objectives of this research were to: (1) evaluate ADOT’s current signal timing design guidelines; and (2) recommend an optimal signal timing design for the Arizona state highway system. A comprehensive evaluation of the effects of the current signal timing design guidelines and a thorough pilot study were used to inform a set of recommendations. These recommendations were used to draft a proposed version of the ADOT’s Guidelines and Processes, which describes the interval duration calculation methods. Proposed changes to the methods include (1) an increase in the approach speed used to calculate left-turn yellow-change intervals; (2) an increase in the intersection speed used to calculate the red-clearance intervals at single-point urban interchanges; and (3) a decrease in the walk speed used to compute “DON’T WALK” interval durations at locations with a high volume of slower-moving pedestrians. These changes would yield increased yellow-change intervals, decreased red-clearance intervals, and longer “DON’T WALK” intervals.]]></description>
      <pubDate>Tue, 27 May 2025 09:33:58 GMT</pubDate>
      <guid>https://trid.trb.org/View/2550937</guid>
    </item>
    <item>
      <title>Reliability Evaluation of Suspension Pipeline Bridges Based on a Bayesian Network</title>
      <link>https://trid.trb.org/View/2526795</link>
      <description><![CDATA[The suspension pipeline bridge is an important structure and a weak link in the process of oil and gas storage and transportation, and research on its reliability is of great significance for the healthy operation of oil and gas pipelines. On the basis of determining the evaluation method, the Yellow River suspension pipeline bridge is taken as the research object and its structural tree model is established. According to the graphical and numerical mapping criteria, the Bayesian network reliability model is created. Not only the failure dynamic prediction of the suspension pipeline bridge has been carried out, but also the accident traceability analysis of the suspension pipeline bridge has been implemented, including sensitivity, boost index, and evolution path. The reliability level of the suspension pipeline bridge is divided, and its graded management is achieved. The following conclusions have been drawn: (1) The structure tree of suspension pipeline bridge is divided into four secondary structures, with a total of 19 basic components. (2) The combination of Delphi method, AHP, and fuzzy probability method can be used to calculate the prior probability. (3) No wind cable structures and the destruction of slope protection significantly lower the reliability of the suspension pipeline bridge. (4) The basic components that mainly affect reliability are pipeline welds, bridge truss, main cables, and towers. (5) The current reliability level of the Yellow River suspension pipeline bridge is level very high (VH).]]></description>
      <pubDate>Tue, 22 Apr 2025 15:51:22 GMT</pubDate>
      <guid>https://trid.trb.org/View/2526795</guid>
    </item>
    <item>
      <title>Dynamic Flashing Yellow Arrow Phase Mode Selection</title>
      <link>https://trid.trb.org/View/2533887</link>
      <description><![CDATA[This project focused on utilizing high-resolution signal data, crash data, and volume data to analyze safety impacts associated with the three left-turn phasing modes that flashing yellow arrows could operate in and determine when the various modes should operate. The three modes were as follows: Protected only; Protected-permissive; Permissive only. The project team needed to analyze the data in two different methods to better understand the results. The analysis was completed for 9 scenarios with different combinations of: Speed (Low/High); Lateral Offset (Positive/Negative); Left-Turn Lane (Single/Dual). The result of this project was a methodology that could be used for future analysis and incorporation of safety data into flashing yellow arrow (FYA) operations decisions. No specific updates were made to the existing FYA phase mode decision spreadsheet.]]></description>
      <pubDate>Thu, 10 Apr 2025 09:21:26 GMT</pubDate>
      <guid>https://trid.trb.org/View/2533887</guid>
    </item>
    <item>
      <title>Impact of countdown timer on drivers’ anticipation at the onset of yellow at signalized intersections</title>
      <link>https://trid.trb.org/View/2516994</link>
      <description><![CDATA[Countdown timers at traffic signals display the time remaining for a phase to terminate, influencing driver behaviour. Studies on their effects at the onset of yellow have generally focused on drivers’ stop/go decisions and dilemma zone, without explicitly addressing how they help drivers anticipate the signal change and make ‘informed decisions’. Therefore, this study first analysed the impact of countdown timer on drivers’ anticipation by comparing brake initiation, deceleration, and speed in the absence and presence of countdown timer. Next, driver behaviour was studied using ‘Accelerated Failure Time’ models. A driving simulator experiment was designed for data collection, with demographic and additional driving behaviour data gathered through a questionnaire. When countdown timer was present, drivers anticipated the onset of yellow, resulting in significant variations in driver behaviour. These variations, in turn, influenced the duration of braking and the time taken to cross the stop line from the onset of yellow.]]></description>
      <pubDate>Tue, 25 Mar 2025 09:28:06 GMT</pubDate>
      <guid>https://trid.trb.org/View/2516994</guid>
    </item>
    <item>
      <title>Reliability of C-ADAS and the importance of the acceleration function for cycling safety</title>
      <link>https://trid.trb.org/View/2508948</link>
      <description><![CDATA[Driving characteristics of bicyclists and motorists differ significantly in critical, uncritical and unaffected situations in road traffic. When bicyclists cross the path of right-turning motorists, bicyclists seem to mitigate conflicts that can develop into crashes, while motorists seem to avoid non-critical but close interactions that can develop into conflicts. This is one of the key findings of the evaluation of a recently developed and successfully tested cooperative driver assistance system (C-ADAS) that warns right-turning motorists of potential collisions. The warning is given by a special traffic light, which we called ‘amber light’, lighting up only in dangerous situations. Whether a situation becomes dangerous or not is determined by a decision tree, fed by the measured kinematics and specific surrogate measures of safety of the interacting road users. Most notably, the results demonstrate that criticality can be rated by measuring anticipation (or surprise) by computing the cross-power spectrum and applying entropy metric on the acceleration functions of the road users. However, one of the outcomes is that the time for the road users to perceive the amber light state might be too low to react properly. These findings can be used to improve the performance of such a C-ADAS.]]></description>
      <pubDate>Wed, 12 Feb 2025 09:00:38 GMT</pubDate>
      <guid>https://trid.trb.org/View/2508948</guid>
    </item>
    <item>
      <title>Empirical analysis of dilemma zone using high-resolution event data</title>
      <link>https://trid.trb.org/View/2459173</link>
      <description><![CDATA[The dilemma zone (DZ) has been physically characterized based on two divergent definitions: Type I and Type II. However, treating DZ differently based on these definitions may lead to inaccurate results of DZ boundary and subsequent safety analyses. Moreover, an integrated empirical assessment of Type I and Type II definitions for consistency in boundary quantification is not yet well-addressed. To this end, the authors empirically analyzed the two DZ definitions by comparing their boundary dynamics with approach velocity and time of day. First, the authors proposed a rule-based matching methodology with 92% accuracy to match actuation events between the advance and stop-bar detectors. This methodology was then applied to process two months of high-resolution event data from an intersection approach, yielding 28,700 vehicle arrivals on yellow. Results showed that 13.2% of approaching vehicles fall into an indecision zone or make Type I-contrary stop/run decisions at the yellow onset. The Type I and Type II DZ boundaries were temporally segregated and did not significantly overlap. The authors' novel findings indicate a lack of consistency in quantifying DZ and emphasize a need for data-driven quantification of the DZ boundary and its dynamics.]]></description>
      <pubDate>Mon, 27 Jan 2025 15:39:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/2459173</guid>
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    <item>
      <title>Safety Impacts of Fluorescent Yellow-Green Signs on Pedestrians</title>
      <link>https://trid.trb.org/View/2452645</link>
      <description><![CDATA[The Manual on Uniform Traffic Control Devices (MUTCD) specifies the use of yellow sheeting for pedestrian or bicycle signs and fluorescent yellow-green (FYG) for school signs, with an option for the use of FYG sheeting for pedestrian or bicycle warning signs. However, switching from yellow or fluorescent yellow (FY) to FYG for pedestrian and bicyclist signage could involve significant cost and effort for government agencies. The objective of this research study is to synthesize existing research and review the state of the practice regarding the use of FYG for pedestrian and bicyclist signs. The research methodology to meet these objectives includes a literature review, survey of departments of transportation (DOTs) and metropolitan planning organizations (MPOs), and follow up interviews with a subset of DOTs and MPOs. Findings from the literature review indicate that the results from previous research studies are inconclusive regarding the safety benefits of FYG (compared to yellow or FY) for pedestrian and bicyclist signs, and the research may be outdated. There is a wide range of agency practices for FYG signs for pedestrians and bicyclists among responding DOTs and MPOs, but many agencies allow FYG for pedestrians and bicyclists to some extent. Responding agencies have primarily switched to FYG for pedestrian and bicyclist signs based on a belief that the color stands out better and as part of other safety initiatives. None of the agencies that responded to the surveys indicated that they have performed any research studies to evaluate the safety performance of FYG signs for pedestrians and bicyclists. While a limited number of responding have seen improved safety performance with the use of FYG, the research did not identify significant and conclusive evidence regarding potential safety benefits associated with the use of FYG for pedestrian and bicyclist signs.]]></description>
      <pubDate>Mon, 13 Jan 2025 10:24:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/2452645</guid>
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