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    <title>Transport Research International Documentation (TRID)</title>
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    <atom:link href="https://trid.trb.org/Record/RSS?s=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" 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>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>The impact of vessel speed reduction on port accidents</title>
      <link>https://trid.trb.org/View/1580210</link>
      <description><![CDATA[Reduced-speed zones (RSZs) have been designated across the world to control emissions from ships and prevent mammal strikes. While some studies have examined the effectiveness of speed reduction on emissions and mammal preservation, few have analyzed the effects of reduced ship speed on vessel safety. Those few studies have not yet measured the relationship between vessel speed and accidents by using real accident data. To fill this gap in the literature, this study estimates the impact of vessel speed reduction on vessel damages, casualties and frequency of vessel accidents. Accidents in RSZ ports were compared to non-RSZ ports by using U.S. Coast Guard data to capture the speed reduction effects. The results show that speed reduction influenced accident frequency as a result of two factors, the fuel price and the RSZ designation. Every $10 increase in the fuel price led to a 10.3% decrease in the number of accidents, and the RSZ designation reduced vessel accidents by 47.9%. However, the results do not clarify the exact impact of speed reduction on accident casualty.]]></description>
      <pubDate>Thu, 28 Feb 2019 09:40:25 GMT</pubDate>
      <guid>https://trid.trb.org/View/1580210</guid>
    </item>
    <item>
      <title>Using horizontal curve speed reduction extracted from the naturalistic driving study to predict curve collision frequency</title>
      <link>https://trid.trb.org/View/1573518</link>
      <description><![CDATA[Many models have been developed to predict collision frequency and evaluate safety performance on horizontal curves. The approach used in data collection or some assumptions made in the analysis methodology might lead to inaccurate results. For example, manual data collection, equipment limitations, and field experiments involving monitoring driving behavior for a specific region for a short-term are potential sources of errors in data collection. This paper aims at overcoming some of these issues in developing models to evaluate safety performance of horizontal curves and predict the curve collision frequency. The developed models relate expected collision frequency on horizontal curves to the speed reduction from the approach tangent to the curve, which is commonly used as a major geometric design consistency measure. The methodology to achieve this objective included three tasks; data collection, evaluating and modeling the viable speed reduction parameters, and developing safety performance models to estimate collision frequency on horizontal curves. Individual drivers’ trips on 49 horizontal curves on rural two-lane highways in rolling and mountainous terrains in Washington State were extracted from the Naturalistic Driving Study (NDS) database. Models were developed to relate different speed reduction parameters to curve characteristics. These models were then applied to 1430 horizontal curves in Washington State to estimate the speed reduction parameters and relate them to collision frequency. Several safety performance models were developed which show that speed reduction, as a design consistency measure, is directly related to collision frequency on horizontal curves. Furthermore, the speed reduction parameters are more significant variables in predicting collision frequency than all curve geometric parameters.]]></description>
      <pubDate>Mon, 28 Jan 2019 10:13:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/1573518</guid>
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    <item>
      <title>Effects of traffic calming measures in different urban areas</title>
      <link>https://trid.trb.org/View/1569045</link>
      <description><![CDATA[Despite of the reduction of deaths and serious injuries in roads in Spain during the last years, this reduction has not been so important in urban areas. Consequently, traffic calming measures (TCMs) have been installed in urban areas to improve mainly safety of pedestrians and cyclists. There is a wide range of existing measures, with varying success. Most of the TCMs are focused on speed reduction, as a way of providing a safer atmosphere to urban zones. Different speed reduction percentages are obtained by each TCM according to their geometric features and emplacements in the road. This paper compares some traffic calming measures in the cities of Bilbao, Burgos, León and Vitoria (located in the north of Spain) in order to evaluate the repeatability of their efficiency in different emplacements. The TCMs selected were some of the most used in these cities. These were raised crosswalks, lane narrowing, radar speed camera signs and radar speed cameras. The speed reductions were compared and analyzed to present some conclusions about the efficiency of each traffic calming measure.]]></description>
      <pubDate>Mon, 03 Dec 2018 12:05:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/1569045</guid>
    </item>
    <item>
      <title>Explaining shipping company participation in voluntary vessel emission reduction programs</title>
      <link>https://trid.trb.org/View/1516739</link>
      <description><![CDATA[Ports are under increasing pressures to increase sustainability and reduce the local and global emissions impacts associated with their operations. Due to limits on their jurisdictional authority, ports may design effective voluntary programs and appropriately motivate participation from global shipping companies that visit their ports. This paper investigates the success of the Vessel Speed Reduction (VSR) Program at the Ports of Los Angeles and Long Beach and uses qualitative methods to analyze the factors that contributed to the success of the program at reducing local air quality pollutants. In particular, why did individual private firms participate in a non-required, voluntary effort? This research found that external pressures such as community concerns about emissions and regulatory threats are important to motivating voluntary behavior and may even be more important than financial incentives. Furthermore, simplicity of program design, clear goals and presence of a monitoring mechanism are important in influencing participation. These findings broaden the authors' understanding of the business strategy behind slow steaming and its applicability as an operational practice as much work to date is focused on how fuel prices and financial incentives influence the choice for shipping companies to slow their speeds. While the VSR program led to significant emission reductions, an additional lesson for voluntary programs is the need for them to evolve and strive for continuous improvement.]]></description>
      <pubDate>Thu, 19 Jul 2018 14:45:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/1516739</guid>
    </item>
    <item>
      <title>Effects of longitudinal speed reduction markings on left-turn direct connectors</title>
      <link>https://trid.trb.org/View/1509100</link>
      <description><![CDATA[Longitudinal speed reduction markings (LSRMs) are designed to alert drivers to an upcoming change in roadway geometry (e.g. direct connectors with smaller radii). In Beijing, LSRMs are usually installed on direct connectors of urban expressways. The objective of this paper is to examine the influence of LSRMs on vehicle operation and driver behavior, and evaluate the decelerating effectiveness of LSRMs on direct connectors with different radii. Empirical data were collected in a driving simulator, and indicators representing vehicle operation status and driving behavior were proposed. To examine the influence of LSRMs, an analysis segment was defined, which begins 500 m prior to the entering point of the connector and ends at the exiting point of the connector. Furthermore, the analysis segment was evenly divided into a series of subsections; the length of each subsection is 50 m. This definition is introduced based on the assumption that drivers would decelerate smoothly in advance of the connector. The analysis results show that drivers tend to decelerate earlier when the radii were 200 m or 300 m. When approaching the connector, drivers tend to decelerate at 500 m thru 250 m in advance of the connector with a 200 m radius; deceleration happens at 300 m–0 m in advance of the connector with a 300 m radius. On the connector, drivers controlled the throttle pedal use at 100 thru 300 m after the entering point when the radius was 200 m; deceleration occurred in two regions when the radius was 300 m: 0 m–900 m from the entering point, and the last 1,000 m of the connector. The analytical results further revealed that LSRMs would be effective at reducing speeds when the radius of the direct connector was 300?m.]]></description>
      <pubDate>Tue, 22 May 2018 17:17:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/1509100</guid>
    </item>
    <item>
      <title>Testing and Evaluating the Effectiveness of Advanced Technologies for Work Zones in Nevada</title>
      <link>https://trid.trb.org/View/1488347</link>
      <description><![CDATA[The objective of this study was to evaluate two advanced technologies for improving safety in work zones: 1) speed monitoring display and 2) automatic work zone information system. In the evaluation of the speed monitoring display (also called a speed trailer), different features of the speed trailer were tested: the size of the speed sign and flashing of the measured speed. In addition, the study also tested the performance of a second speed trailer in a work zone. Two test sites in the Las Vegas Area were chosen to test the speed trailer, one on a fully controlled access segment of Cr-215, a county principal arterial, and the other on I-15, a major Interstate highway. The basic scenarios tested at these two sites were (1) no new feature, 2) smaller sign, 3) bigger sign without flashing, 4) bigger sign with a fast flashing rate, and 5) bigger sign with a slow flashing rate. On Cr-215, an additional scenario for the warning message “Slow Down” was also included. To evaluate the performance of the tested systems, speed and vehicle classification data were collected using Nu-metrics detectors on Cr-215. On I-15, however, these data were collected using videos processed in house. Comparisons were made on the speeds collected in these scenarios. The comparisons were first made between a ‘before’ condition where a speed monitoring display was not deployed and an ‘after’ condition using one of the scenarios. From these comparisons, it can be seen whether these technology features were effective in reducing vehicle speeds. The speeds were compared later between different scenarios to identify the relative performance of the features. The comparisons considered different types of vehicles and whether they ran in free flow conditions. These comparisons were based on both the hypothesis testing method and regression modeling. The hypothesis tests were looking into whether average speeds and speeding rate changed significantly between scenarios. The regression modeling investigated the likelihood of speeding and the speed at which a vehicle would run. The results from these two methods supported each other, which was a way to vary the results of the tests conducted in this study. The evaluation of the automatic work zone information system was performed by first developing such a system. In this study, a simple automatic work zone information system was developed which consisted of video detection at two locations, line-of-sight radio frequency wireless communication, and one portable variable message sign. The system was tested on I-515 and evaluated from the perspectives of traffic diversion and speed reduction. The analysis used for evaluation was based only on hypothesis testing for traffic flow and speed.]]></description>
      <pubDate>Mon, 20 Nov 2017 16:45:17 GMT</pubDate>
      <guid>https://trid.trb.org/View/1488347</guid>
    </item>
    <item>
      <title>Rerouting and Speed Reduction of Hazardous Material Trains in Selected Conrail Corridors</title>
      <link>https://trid.trb.org/View/1485735</link>
      <description><![CDATA[Rerouting and speed reduction of trains carrying hazardous materials shipments are analyzed so as to determine effects on railroad operations and costs and population exposure. A case study format was utilized on two corridors within the Conrail system. Segments of mainline which are in proximity to population concentrations were identified. On those segments, the analysis assumed that hazardous materials traffic would be either prohibited - thus causing rerouting - or would be carried at reduced speed. Implications of the two policies (prohibit and reduce speed) are discussed.]]></description>
      <pubDate>Thu, 26 Oct 2017 12:32:28 GMT</pubDate>
      <guid>https://trid.trb.org/View/1485735</guid>
    </item>
    <item>
      <title>Evaluation of Automated Flagger Assistance Devices</title>
      <link>https://trid.trb.org/View/1480137</link>
      <description><![CDATA[Flagger safety is an important issue in work zones due to the proximity of the flagger to traffic. Some strategies for improving flagger safety include slowing down approaching vehicles or removing flaggers from the immediate vicinity of traffic. The Automated Flagger Assistance Device (AFAD) is a system that can potentially accomplish both of the aforementioned strategies. In order to validate the effectiveness of AFADs in highway work zones, field testing was performed using an AFAD with a Changeable Message Sign (CMS) on a 2-lane work zone in Missouri. The field study found that AFADs helped to lower approach speeds and encouraged vehicles to stop farther behind the AFAD than a traditional flagger. In addition, a driver intercept survey found that the AFAD was viewed favorably by the general public. These field results found that AFADs are more effective than human flaggers, and drivers prefer AFADs over human flaggers.]]></description>
      <pubDate>Mon, 21 Aug 2017 11:15:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/1480137</guid>
    </item>
    <item>
      <title>Effects of linear holding for reducing additional flight delays without extra fuel consumption</title>
      <link>https://trid.trb.org/View/1470076</link>
      <description><![CDATA[This paper presents an approach to implement linear holding (LH) for flights initially subject to ground holding, in the context of Trajectory Based Operations. The aim is to neutralize additional delays raised from the lack of coordination between various traffic management initiatives (TMIs) and without incurring extra fuel consumption. Firstly, motivated from previous works on the features of LH to absorb delays airborne, a potential applicability of LH to compensate part of the fixed ground holding is proposed. Then, the dynamic adjustment of LH in response to TMIs-associated tactical delays is formulated as a multi-stage aircraft trajectory optimization problem, addressing both pre- and post-departure additional delays. Results suggest that additional delays of 25 mins in a typical case study can be totally recovered at no extra fuel cost. A notable extent of delay reduction observed from the computational experiments further supports the benefits of LH for reducing different combinations of additional delays without consuming extra fuel.]]></description>
      <pubDate>Fri, 30 Jun 2017 19:44:50 GMT</pubDate>
      <guid>https://trid.trb.org/View/1470076</guid>
    </item>
    <item>
      <title>Reducing speed and fuel transfer of the Green Flag Incentive Program in Kaohsiung Port Taiwan</title>
      <link>https://trid.trb.org/View/1409604</link>
      <description><![CDATA[This research applied the Green Flag Program to assess the benefits of reducing speed and fuel transfer for large merchant vessels (bulk and container) entering Kaohsiung Port. This study adopts an activity-based model to calculate fuel consumption and emissions, as well as setting up two scenarios, (1) decrease vessel speed to 12 knots 20 nm away from port; and (2) decrease vessel speed to 12 knots and transfer fuel 20 nm away from port, which based on the Green Flag Program in Long Beach, in the U.S. The findings are (1) In scenario one, the container and bulk vessels saw reductions in CO₂ emissions of about 41% and 14%, respectively. In scenario two, container and bulk vessels had reductions of about 48% and 43% in SO₂ emissions, respectively. (2) Large vessels are more environmentally friendly than small vessels. (3) Using the CATCH model to assess the effectiveness of the two scenarios, it was found that container vessels benefited from both reducing speed and fuel transfer, while bulk carriers only did so from the former.]]></description>
      <pubDate>Tue, 28 Jun 2016 16:37:26 GMT</pubDate>
      <guid>https://trid.trb.org/View/1409604</guid>
    </item>
    <item>
      <title>Examining the Impacts of Portable Changeable Message Signs on Drivers' Speed Characteristics: A Driving Simulator Study</title>
      <link>https://trid.trb.org/View/1394519</link>
      <description><![CDATA[Using a driving simulator (DS), this paper analyzes the speeding behavior of drivers impacted by four different messages displayed on portable changeable message signs (PCMS) placed upstream from a construction zone on an interstate highway in Missouri. The four PCMS placed sequentially replicated the Missouri work zone and participants evaluated the messages displayed in a DS. The effects on drivers’ speed as a result of these messages were analyzed at eight locations, 1000 ft. before and after each PCMS. Five different scenarios (0-4) were simulated; control scenario set up with static signs. In Scenario 1, “Caution Work Zone Ahead: Reduce Speed Ahead” was displayed on the PCMS. Scenario 2 utilized (MS-2), “Speed Ahead 30 mph/2 mins to end of Work Zone.” Scenario 3 tested “Prepare to stop/2 mins to end of Work Zone”, and Scenario 4 deployed “Prepare to stop/Stopped Traffic Ahead.” Scenarios 1-4 were compared to the control scenario; Scenario 4 had the highest speed reduction, followed by Scenario 3, Scenario 2, and Scenario 1. The 85th 13 percentile speeds in the work zone closely matched with the displayed speed for MS-2. A significant reduction in speed was found on the eighth interval as it was placed before the start of the lane closure. Results from a drivers’ survey conducted after the DS experiment, indicated that MS-2 was the preferred message as it displayed a specific speed for the participants to follow. The results from the survey reinforced that PCMS were effective in reducing the speeds of the drivers.]]></description>
      <pubDate>Thu, 10 Mar 2016 16:07:58 GMT</pubDate>
      <guid>https://trid.trb.org/View/1394519</guid>
    </item>
    <item>
      <title>Safety effects of reducing the speed limit from 90 km/h to 70 km/h</title>
      <link>https://trid.trb.org/View/1286813</link>
      <description><![CDATA[Speed is one of the main risk factors in traffic safety, as it increases both the chances and the severity of a crash. In order to achieve improved traffic safety by influencing the speed of travel, road authorities may decide to lower the legally imposed speed limits. In 2001 the Flemish government decided to lower speed limits from 90 km/h to 70 km/h on a considerable number of highways. The present study examines the effectiveness of this measure using a comparison group before- and after study to account for general trend effects in road safety. Sixty-one road sections with a total length of 116 km were included. The speed limits for those locations were restricted in 2001 and 2002. The comparison group consisted of 19 road sections with a total length of 53 km and an unchanged speed limit of 90 km/h throughout the research period. Taking trend into account, the analyses showed a 5% decrease [0.88; 1.03] in the crash rates after the speed limit restriction. A greater effect was identified in the case of crashes involving serious injuries and fatalities, which showed a decrease of 33% [0.57; 0.79]. Separate analyses between crashes at intersections and at road sections showed a higher effectiveness at road sections. It can be concluded from this study that speed limit restrictions do have a favorable effect on traffic safety, especially on severe crashes. Future research should examine the cause for the difference in the effect between road sections and intersections that was identified, taking vehicle speeds into account.]]></description>
      <pubDate>Wed, 26 Mar 2014 10:11:20 GMT</pubDate>
      <guid>https://trid.trb.org/View/1286813</guid>
    </item>
    <item>
      <title>A simulator study on the impact of traffic calming measures in urban areas on driving behavior and workload</title>
      <link>https://trid.trb.org/View/1280123</link>
      <description><![CDATA[This study examined the impact of traffic calming measures (TCM) on major roads in rural and urban areas. More specifically the authors investigated the effect of gate constructions located at the entrance of the urban area and horizontal curves within the urban area on driving behavior and workload. Forty-six participants completed a 34 km test-drive on a driving simulator with eight thoroughfare configurations, i.e., 2 (curves: present, absent) × 2 (gates: present, absent) × 2 (peripheral detection task (PDT): present, absent) in a within-subject design.  PDT performance (mean response time (RT) and hit rate) indicated that drivers experienced the road outside the urban area as cognitively less demanding relative to the more complex road environment inside the urban area. Whereas curves induced a speed reduction that was sustained throughout the entire urban area, variability of acceleration/deceleration and lateral position were increased. In addition, PDT performance indicated higher workload when curves were present (versus absent). Gate constructions locally reduced speed (i.e., shortly before and after the entrance) and slightly increased variability of acceleration/deceleration and lateral position nearby the entrance. However, the effects on SDL-A/D and SDLP are too small to expect traffic safety problems.  It can be concluded that both curves and gate constructions can improve traffic safety. Notwithstanding, the decision to implement these measures will depend on contextual factors such as whether the road serves a traffic-, rather than a residential function.]]></description>
      <pubDate>Mon, 30 Dec 2013 11:05:23 GMT</pubDate>
      <guid>https://trid.trb.org/View/1280123</guid>
    </item>
    <item>
      <title>Experimental research on the effectiveness of speed reduction markings based on driving simulation: A case study</title>
      <link>https://trid.trb.org/View/1278836</link>
      <description><![CDATA[The objective of this paper is to test the effectiveness of speed reduction markings (SRMs). The empirical data including vehicle operations and drivers’ psychological and physical reactions were collected in a driving simulator. An index—the relative speed difference—was developed to evaluate the effectiveness of speed reduction markings. Researchers analyzed data to test the effectiveness of speed reduction markings and quantitatively study their effects and the deceleration process. Out of 15 subjects, there were 1 (7%), 2 (13%), and 7 (47%) subjects who decelerated while driving through the downhill section in the No SRMs scenario, Longitudinal SRMs scenario and Transverse SRMs scenario, respectively. In terms of speed and subjects’ decelerating maneuver, the results of the analysis of variance (ANOVA) and the contrast analysis (S–N–K method) showed that transverse speed reduction markings (TSRMs) could significantly influence subjects’ speed choice and maneuver (P < 0.05).]]></description>
      <pubDate>Mon, 23 Dec 2013 07:52:11 GMT</pubDate>
      <guid>https://trid.trb.org/View/1278836</guid>
    </item>
    <item>
      <title>Speed limit effectiveness in short-term rural interstate work zones</title>
      <link>https://trid.trb.org/View/1250314</link>
      <description><![CDATA[Average speed and speed variance are two characteristics of traffic flow that affect accident rates and severity near work zones. Operationally, work zones account for approximately 24% of the non-recurring delay. A policy for work zone speed limits has to delicately balance the safety and the efficiency impacts. If speeds are set too low, then avoidable congestion and speed violations might result. If speeds are set too high then, again, safety may be compromised. In this paper, results from field studies conducted on three Interstate 70 maintenance short-term work zones in rural Missouri are presented for three different speed limit scenarios: no posted speed limit reduction, 10 mph posted speed limit reduction, and 20 mph posted speed limit reduction. The 85th percentile speeds and standard deviation of speed were found to be 81 and 10 mph; 62 and 8 mph; and 48 and 6 mph, respectively for the three scenarios. The differences in 85th percentile speed and standard deviation of speed among all three scenarios were statistically significant. The per cent of drivers who exceed speed limit by over 10 mph were 15·4, 4·8, and 0·9%, respectively. Thus a reduction in posted speed limit was effective in reducing prevailing speeds and speed variances in short-term work zones in rural Missouri.]]></description>
      <pubDate>Mon, 17 Jun 2013 14:16:12 GMT</pubDate>
      <guid>https://trid.trb.org/View/1250314</guid>
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