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    <title>Transport Research International Documentation (TRID)</title>
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    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
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      <title>A-TEAM phase 1: final report</title>
      <link>https://trid.trb.org/View/1506434</link>
      <description><![CDATA[A-TEAM phase 1 targeted, through research, the development of three method packages for important scenarios where research and development is needed for active safety systems. The research about methods took place in work packages WP4, 5, and 6, where WP4 focused on accidents with oncoming traffic, WP5 contained vulnerable road users research, and WP6 focused on rear-end situations where heavy vehicles closes in on a another vehicle from the rear. To ensure that the methods would have relevance in real-world traffic, the method work was started after the field data research in WP3 had reached solid results. In WP3, accident statistics and further research projects on European level were used as sources to define the most important scenarios. Thereafter, analytical methods were used to condense the statistical data from WP3 into the test cases that were further researched in WP4, 5, and 6. WP7 was used to exploit the results from A-TEAM phase 1 in a successful way. Its goal was to address the test equipment shortcomings and demonstrate a test system where the methods could be performed. Even taking the work in the scenario, method, and test demonstrator work packages into account, it was clear from the beginning that A-TEAM phase 1 could only address a minor part of the total method research needed. To map out further as well as complementary research needs, WP2 conducted a pre-study focusing on the next few years. The objectives of A-TEAM phase 1 were: 1. Through research, define accident scenarios within intersection collisions, accidents with heavy vehicles, and accidents with vulnerable road users including requirements. 2. Create new knowledge about how other accident and autonomous vehicle scenarios not included in A-TEAM phase 1 can be solved. 3. Create test methods for the scenarios. 4. Demonstrate a test system where the test methods can be conducted with high quality and efficiency. 5. Foster innovation, cooperation, and competence development within all areas above.]]></description>
      <pubDate>Wed, 28 Mar 2018 10:25:48 GMT</pubDate>
      <guid>https://trid.trb.org/View/1506434</guid>
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      <title>Helping Vehicles 'See' Motorcyclists Could Cut Crashes</title>
      <link>https://trid.trb.org/View/1490005</link>
      <description><![CDATA[This article summarizes a new research study from the Insurance Institute for Highway Safety (IIHS) that found that more than 8,000 two-vehicle crashes with motorcycles could be avoided by equipping passenger vehicles with front crash prevention, lane maintenance, and detection systems specifically designed to detect motorcycles.  The author first reminds readers of earlier studies that show the general benefits for collision avoidance technologies, then focuses on special systems designed to detect motorcyclists.  This present study evaluated two-vehicle crashes between a motorcycle and a passenger vehicle that occurred on U.S. roads during 2011-15.  The researchers determined whether any of the three crash avoidance technologies were present and the characteristics of the crash.  Most of the two-vehicle crashes relevant to front crash prevention involved the front of the passenger vehicle rear-ending a motorcycle.  The author also discusses crashes relevant to lane maintenance and sideswipe crashes.  A final section considers the role of antilock braking systems (ABS).  Readers are referred to a link for the full research paper.]]></description>
      <pubDate>Wed, 29 Nov 2017 10:00:27 GMT</pubDate>
      <guid>https://trid.trb.org/View/1490005</guid>
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    <item>
      <title>Development of exposure measures for highway safety analysis; volumes 1 and 2</title>
      <link>https://trid.trb.org/View/1181005</link>
      <description><![CDATA[This report describes the rationale of, methodology, and results of an FHWA-sponsored study aimed at developing meaningful and accurate measures of exposure to accidents at urban signalized intersections.  In earlier FHWA developmental work, basic traditional definitions of exposure used in roadway- related research were examined and alternative measures were proposed.  This current project expanded this earlier work in an iterative process involving project staff effort and inputs from FHWA personnel and a panel of expert reviewers.  First, the original formulas were modified and were field tested using data consisting of videotaped traffic flows at a sample of intersections.  In the second phase of the effort, additional field data were coded and final formula modifications were made using log-linear and non-linear regression analysis.  The result is a series of exposure measures for head-on, rear-end, sideswipe, angle, and left -turning exposure for intersections characterized by unprotected, protected, and protected/permissive left-turn phasing.  This work represents a step in the ongoing process of defining and refining exposure measures for use in the formation of accident rates.  Issues still remain related to the use of nonflow parameters in the estimating formulas (eg, signal phasing and cycle length), and to the question of verification of the measures against accidents.  Problems with such verification and suggestions for future research are presented (A).]]></description>
      <pubDate>Fri, 24 Aug 2012 03:13:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/1181005</guid>
    </item>
    <item>
      <title>A Test Track Protocol for Assessing Forward Collision Warning Driver-Vehicle Interface Effectiveness</title>
      <link>https://trid.trb.org/View/1122395</link>
      <description><![CDATA[The primary objective of the work described in this report was to develop a protocol suitable for evaluating forward collision warning (FCW) driver-vehicle interface (DVI) effectiveness. Specifically, this protocol was developed to examine how distracted drivers respond to FCW alerts in a crash imminent scenario. To validate the protocol, a diverse sample of 64 drivers was recruited from central Ohio for participation in a small-scale, test track based human factors study. Each participant was asked to follow a moving lead vehicle (MLV) within the confines of a controlled test course and, while attempting to maintain a constant headway, instructed to perform a series of four distraction tasks intended to briefly divert their attention away from a forward-viewing position. With the participant fully distracted during the final task, the MLV was abruptly steered out of the travel lane, revealing a stationary lead vehicle (SLV) in the participant’s immediate path (a realistic-looking full-size balloon car). At a nominal time-to-collision (TTC) of 2.1s from the stationary vehicle, one of eight FCW alerts was presented to the distracted participant. Each alert modality was intended to emulate one or more elements from those presently available in contemporary vehicles. The timing of the critical events contained within the protocol appears to be repeatable, appropriate, and effective. With respect to evaluation metrics, the data produced during this study indicate that reaction time and crash outcome provide good measures of FCW alert effectiveness, where reaction time is best defined as the onset of FCW to the instant the driver’s forward-facing view is reestablished. Using these criteria, the seat belt pretensioner-based FCW alerts used in this study elicited the most effective crash avoidance performance. That said, of the 32 trials performed with some form of seat belt pretensioner-based FCW alert, 53.1 percent of them still resulted in a crash. FCW modality had a significant effect on the participant reaction time from the onset of an FCW alert, and on the speed reductions resulting from the participants’ avoidance maneuvers (regardless of whether a collision ultimately occurred). Differences in participant response times from the instant their forward-facing view was reestablished to throttle release, brake application, and avoidance steer were not significant, nor were brake application and avoidance steer magnitudes.]]></description>
      <pubDate>Thu, 01 Dec 2011 09:56:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/1122395</guid>
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    <item>
      <title>Relationship between Skid Resistance Numbers Measured with Ribbed and Smooth Tire and Wet Accident Locations</title>
      <link>https://trid.trb.org/View/878575</link>
      <description><![CDATA[Due to the recent strategic initiative adopted by the Ohio Department of Transportation (ODOT) to reduce highway crashes, there is a current need to determine if surface friction testing results can be correlated to wet weather crash data in Ohio. The establishment of such correlations would allot ODOT to develop a proactive wet-pavement accident reduction program that would effectively predict locations where wet-pavement crashes may likely occur. Under this study, research was conducted to determine if surface characteristic measurement can be correlated to wet-weather accidents and guidance was provided on the identification of desirable or target friction numbers as a function of site categories and friction demand. A comprehensive literature review was first conducted on pavement surface characteristics, including a review of international research activities. This was followed by a field testing program to evaluate smooth- and ribbed-tire surface friction, as well as pavement macrotexture and roughness, at 90 locations through the state. The 90 sections that were selected represent three site categories: signalized intersections, unsignalized intersections, and congested freeways. These site categories were considered to have the most potential to reduce rear-end crashes. The surface characteristics data from the 90 pavement sections were then analyzed with regards to crash data using both trend analysis and regression modeling techniques. Based on the finding from the field testing program and the available information in the literature, preliminary recommendations were developed for ODOT to consider in its quest for improving the safety of its roadway network. The main body of this report includes an abbreviated summary of the extensive literature search of both U.S. and international studies, a detailed description of the field testing program, a summary of data analysis procedures, a summary of the findings and conclusions, and a summary of the final recommendations for implementation.]]></description>
      <pubDate>Thu, 22 Jan 2009 09:33:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/878575</guid>
    </item>
    <item>
      <title>Crash Energy Absorption for High-Speed Rail Passenger Seats Using Solid Ejection Material</title>
      <link>https://trid.trb.org/View/860736</link>
      <description><![CDATA[This Innovations Deserving Exploratory Analysis (IDEA) project assessed the potential of Solid Ejection Material (SEM) crash energy absorption technology for High-Speed Rail applications. A basic SEM model consists of an impact piston inside of a shock housing, and the end of the piston inside the housing is in contact with a ductile or yieldable solid (polymer). The housing contains an ejection groove or ejection ports. If the piston is impacted, such as in a collision, the other end of the piston forces the ductile or yieldable solid through the ejection groove or ports, thereby absorbing much of the crash energy. The specific application for this technology investigation was an SEM shock track for the mounting of seats in rail passenger cars. In the event of, for example, a head-end or rear-end collision, the SEM shock track mounting would provide controlled acceleration and deceleration of the seat assembly. Although rail passengers do not wear seat restraints, the controlled acceleration-deceleration would provide some protection to passengers thrown into the back of the seat in the event of a head-end collision. In the event of a rear-end collision, the shock track would absorb much of the energy forcing the seats to the rear. The shock track would also reduce the likelihood of the breakaway of seat assemblies. Tasks included the identification of relevant railcar seat crashworthiness specifications (FRA, APTA, overseas), the design of the SEM crash energy absorption system for the seats and for an impact barrier, fabrication of an impact test Bogie vehicle equipped with railcar passenger seats and an instrumented test dummy, and a series of crash tests. These SEM energy absorbers were incorporated into the floor and wall attachments of passenger seats mounted on a Bogie crash test vehicle. The rear seat of the two-seat test vehicle contained three test dummies, one of which was instrumented to record the dummy’s secondary impact loads with the forward seat when the test vehicle impacted a barrier. Comparison of impact data (e.g., head impact and femur load values), with and without the SEM shocks revealed no significant differences in injury levels. The SEM shocks used in both the seat attachments and the impact barrier performed in accordance with the design specifications. Thus, the lack of reductions in injury levels was not due to any failure of the SEM shocks. It was due to several other factors, including the relatively high velocity differential between the seat and test dummies at impact; and the relatively high seat mass that needed to be accelerated by the colliding test dummies (both of these factors contributed to the high initial spike loads). But the primary reason there was little variance in the load performance between the SEM-modified and stock seats was due to the seat structures, which were designed to yield under the impact loading as defined in the current passenger seat specifications. So the seats underwent some level of yielding even with SEM shock mods. If a stiffer test seat model had been employed in this study (HSR-45), there likely would have been more discernable injury load improvements with the SEM shock absorbers.]]></description>
      <pubDate>Fri, 13 Jun 2008 09:07:03 GMT</pubDate>
      <guid>https://trid.trb.org/View/860736</guid>
    </item>
    <item>
      <title>Frequency of Work Zone Accidents on Construction Projects</title>
      <link>https://trid.trb.org/View/773165</link>
      <description><![CDATA[The overall objective of this research was to study work zone accidents in New York State, with particular attention to the occurrence and mitigation of rear-end vehicle accidents. The specific objectives were to: (1)  Recommend changes to the NYSDOT’s accident database system for more efficient management and analysis; (2) Conduct a detailed investigation of rear-end crashes in work zones and recommend measures that can reduce the frequency of these types of crashes; and (3) Report on traffic exposure data and accident patterns / parameters to be incorporated into future NYSDOT accident data analysis. Task 1 focused on evaluating the current NYSDOT work zone accident reporting system, surveying practices used in other states, and providing recommendations for improvement. The results of this task revealed that the current NYSDOT work zone accident reporting system is the most comprehensive in the country. Further changes to improve the system were recommended based on a review of the literature and practices being implemented in other state agencies. The first part of Task 2 was focused on analyzing rear-end accidents in work zones that occurred in New York State between 1994 and 2001. Since data were available only on work zones that had accidents, truncated count data models were estimated to study the relationship between crash frequency and work zone characteristics. Ordered probit models were developed to study crash severity. The second part of Task 2 provides some corrective actions to reduce frequency of work zone accidents. These actions are primarily based on a review of the literature since information on changes made by NYSDOT at the project level was not available to the research team. The first subtask of Task 3 provided some recommendations to incorporate more project information to the work zone database either through adding more variables or including project information in a separate database that can be linked through a project identification number. The second subtask of Task 3 focused on various venues and approaches for obtaining exposure to traffic for various types of work zones. The final subtask of Task 3 focused on identifying parameters correlated with work zones and the county level.]]></description>
      <pubDate>Tue, 31 Jan 2006 12:25:36 GMT</pubDate>
      <guid>https://trid.trb.org/View/773165</guid>
    </item>
    <item>
      <title>EVALUATING THE USE OF RED LIGHT RUNNING PHOTOGRAPHIC ENFORCEMENT USING COLLISIONS AND RED LIGHT RUNNING VIOLATIONS</title>
      <link>https://trid.trb.org/View/753643</link>
      <description><![CDATA[The issue of red light running (RLR) has long been a problem throughout the United States.  There is considerable debate within the general public and public agencies regarding the use of photographic enforcement to deter red light violations.  Many studies have been conducted on the effectiveness of red light cameras (RLCs) at reducing collisions.  However, the question still remains as to whether RLCs actually change driver behavior. The need for more thorough study motivated this research effort to help define the effectiveness of RLCs within the City of Raleigh, North Carolina.  Four specific tasks were identified to help in this research effort.  First, a literature review was conducted.  Many studies indicate that RLC enforcement reduces the frequency of collisions at treated intersections.  However, there are a limited number of rigorous studies (especially those in the United States and in North Carolina). Six focus groups were convened in an effort to gather information on attitudes, opinions, and beliefs associated with photographic enforcement to better enhance traffic law enforcement.  Two community and four professional focus groups were assembled.  Overall, the perception of photographic enforcement was positive.  The majority of participants agreed that the presence of RLCs would make them more aware of individual driver behavior; however, most of the groups agreed that the range of driver education varied widely and that driver education should be a priority.  In an effort to analyze the effect of RLCs on driver behavior, two types of analyses were completed.  The first type of analysis was a before-after collision study.  The following three types of improved before-after collision studies were used:  accounting for causal factors, a comparison group analysis, and an improved comparison group analysis accounting for the halo-effect.  Each of these studies analyzed four categories of collisions including total, red light running related, angle, and rear end.  Based on the comparison group study, collisions were effectively reduced by 17%, 22%, 42% and 25%, respectively.  In addition to the analysis of collisions, red light running violations were analyzed to see if there was a change in driver behavior related to dangerous violation times (violations considered to possibly cause collisions) greater than two seconds.  Using the Chi-Square Test of Independence, the frequency of unsafe red light running violations reduced significantly with a p-value less than 0.001. Based on these findings, RLCs appear to have a positive effect on driver behavior.  Focus groups indicate that overall there is a positive perception of RLCs as a countermeasure to deter red light running.  Based on the comparison group collision study, all collision group types decreased considerably.  Lastly, red light running violations related to dangerous red light violation times dramatically decreased, providing further justification for the use of RLCs as a red light running countermeasure.]]></description>
      <pubDate>Mon, 28 Mar 2005 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/753643</guid>
    </item>
    <item>
      <title>EVALUATION OF RED LIGHT CAMERA (PHOTO-RED) ENFORCEMENT PROGRAMS IN VIRGINIA: A REPORT IN RESPONSE TO A REQUEST BY VIRGINIA'S SECRETARY OF TRANSPORTATION</title>
      <link>https://trid.trb.org/View/753523</link>
      <description><![CDATA[Red light running, which is defined as the act of a motorist entering an intersection after the traffic signal has turned red, caused almost 5,000 crashes in Virginia in 2003, resulting in at least 18 deaths and more than 3,800 injuries.  In response to a June 2, 2004, directive from Virginia Secretary of Transportation Whittington W. Clement, an evaluation of the photo-red enforcement programs that operate in Virginia was undertaken.  Generally, Virginia's photo-red programs are technically feasible.  Case law strongly indicates that the programs pass legal muster in the three key areas: privacy, equal protection, and due process, and public opinion surveys suggest that roughly two-thirds of respondents support red light cameras.  There is, however, a practical issue with regard to issuing citations for out-of-state motorists, as noted in the report.  Although an economic analysis was not feasible in the study time frame, a limited fiscal analysis suggests that, in general, Virginia localities are not generating net revenue. Finally, an operational analysis based on violations and crashes shows a potential but not definite safety improvement.  The cameras clearly affect driver behavior; across the 23 intersections where reliable citation data could be obtained, citations decreased by an average of 21% per intersection. Further the data show that the cameras are correlated with a definite decrease in crashes that are directly attributable to red light running, a definite increase in rear-end crashes, a possible decrease in angle crashes, a net decrease in injury crashes attributable to red light running, and an increase in total injury crashes.  More time is needed to determine whether the severity of the eliminated red light running crashes was greater than that of the induced rear-end crashes.  The report recommends that Virginia's photo-red enforcement programs be continued for an additional year to resolve this question and to collect additional data that was not feasible during the 6-month time frame of this report.]]></description>
      <pubDate>Thu, 03 Mar 2005 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/753523</guid>
    </item>
    <item>
      <title>RATIONAL SCHEDULE OF BASE ACCIDENT RATES FOR RURAL HIGHWAYS IN OHIO (PHASE II)</title>
      <link>https://trid.trb.org/View/697957</link>
      <description><![CDATA[A "base accident rate", also known as "expected value", allows safety engineers or planners to objectively determine whether an accident pattern at a study location is significantly higher than the same accident pattern at other locations with similar geometric, traffic, and environmental factors.  This study was conducted to develop base accident rates for rural highways at non-intersections in Ohio using all the available data from the Ohio Department of Transportation's database.  Using a random sampling technique, 30% of the data for each of the 12 districts was extracted and a comprehensive database was created for each district.  Then, the highway sections were generally divided into uniform segments of length 0.25 mile.  For each highway segment, population density data within one-mile radius was generated.  Additional data, namely, number of residential and business driveways, number of passing zones, horizontal and vertical curves, and guardrail length were manually recorded using photolog discs.  A master database was created for each district using the above-mentioned data.  The base accident rates were developed for ten accident types, namely, (i) Total accidents, (ii) Injury accidents, (iii) Property Damage Only accidents, (iv) Fixed-Object accidents, (v) Sideswipe accidents, (vi) Rear-End accidents, (vii) Left-Turn accidents, (viii) Right-Angle accidents, (ix) Wet Pavement accidents, and (x) Night accidents.  Fourteen independent variables were used in the development of the base rates.  Automatic Interaction Detection (AID) technique was used to evaluate the complex interaction between the dependent and independent variables. The AID technique assisted in identifying a set of independent variables that have significant relationship with each dependent variable.  Based on the results of this study, it is recommended that accident density (and not accident rate) be considered as the primary unit for accident analysis for non-intersections. It is recommended that the means and standard deviations for each accident type as provided in the report be used as a method for calculating base accident densities/rates for the individual districts as well as for the entire State.  It is also recommended that the regression equations developed for the individual districts and the whole State be used as an additional tool for estimating base accident densities/rates for each accident type on rural non-intersections in Ohio.  An additional work completed in this project was the new and upgraded version of the knowledge-based expert system called RITA (Rural Highway Safety Advisor) that codifies within its knowledge base the procedures, techniques and rules of thumb (heuristic) involved in the process of conducting highway safety analysis for non-intersections, signalized intersections and non-signalized intersections that commonly exist in the rural highways in Ohio.  The results of the base accident rate study and RITA are amenable for immediate implementation.]]></description>
      <pubDate>Thu, 13 May 2004 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/697957</guid>
    </item>
    <item>
      <title>EFFECTIVENESS OF TWO-WAY STOP CONTROL AT LOW-VOLUME RURAL INTERSECTIONS</title>
      <link>https://trid.trb.org/View/697933</link>
      <description><![CDATA[The goal of this research effort was to investigate the development of specific (i.e., quantifiable) warrants for the installation of 2-way STOP control at low volume rural intersections in Kansas.  It is the recommendation of this study that state and local agencies continue to use the guidelines in the Manual on Uniform Traffic Control Devices (MUTCD) as the basis for assessing the need for 2-way STOP control at low volume intersections.  This report provides a general methodology that the traffic engineer can use to assess the sight distance and crash history considerations addressed in the MUTCD warrants, as well as driver error and other human factors that might influence the decision to use STOP control.  The study further recommends the use of Commentary Driving as a means to address these various factors in a systematic and comprehensive manner.  In assessing the need for STOP control in terms of intersection crash history, the following additional guidelines should be considered.  For low speed rural intersections, STOP control may be effective in reducing traffic crashes.  In the case of high-speed intersections, there is evidence which suggests that STOP control may not be an effective means of reducing traffic crashes.  However, until this issue is resolved, it is suggested that STOP control be considered for intersections with three to four crashes in a 3-year period.  This general guideline is applicable to crash types that may be correctable by application of STOP control (i.e., side swipe, angle and rear end collisions).  In evaluating this guideline, the engineer should also consider other countermeasures that have been shown to be effective in addressing safety problems at rural intersections.  These countermeasures could include sight distance improvements, speed control measures, and/or geometric improvements such as increased curb radii.  At high-speed roadway intersections, the engineer may also wish to consider advance warning or advisory signing on the major roadway approaches to the intersection.]]></description>
      <pubDate>Mon, 10 May 2004 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/697933</guid>
    </item>
    <item>
      <title>ENHANCED REAR LIGHTING AND SIGNALING SYSTEMS: LITERATURE REVIEW AND ANALYSES OF ALTERNATIVE SYSTEM CONCEPTS</title>
      <link>https://trid.trb.org/View/679001</link>
      <description><![CDATA[Rear-end crashes are the most frequently occurring type of collision, accounting for approximately 29% of all crashes and resulting in a substantial number of injuries and fatalities each year.  Rear-end collisions in which the lead vehicle is stopped or moving very slowly prior to the crash account for the majority of these accidents.  Over the years several initiatives have addressed the problem of rear-end crashes, with limited success. The most public of these ventures was the center high-mounted stop lamp (CHMSL), which was required to be present on automobiles beginning with model year 1986.  The long-term effectiveness of the CHMSL has leveled off at about a 4% effectiveness in preventing rear-end crashes, which means there is still much room for improvement.  The goal of this research effort is to develop and test a small number of enhanced rear-lighting concepts that have the potential to reduce the number of rear-end collisions.  These are to include problems with stopped vehicles.  This report encompasses the first task of the research effort.  Task 1 involved investigating all previous efforts to develop enhanced rear-lighting systems, determining the causes of rear-end crashes, and developing a short list of rear-lighting alternatives to be tested in future research efforts under this project.  The literature review revealed that numerous rear-lighting systems have been proposed over the past 30 years.  Focus groups conducted with law enforcement officers found that the most common cause of rear-end crashes is driver inattention and distraction, with following too closely as the next most common cause.  A review of several crash database analyses revealed similar results, as did a study in which drivers of striking vehicles were interviewed.  The final subtask was to conduct a trade study to suggest two to three rear-lighting concepts for further study. An expert panel consisting of twelve rear-lighting experts was assembled.  The trade study was conducted electronically (email) via a series of three questionnaires.  This process resulted in the recommendation of three rear-lighting configurations for further refinement.  Algorithms for the activation and deactivation of these systems were also developed during Task 1.]]></description>
      <pubDate>Fri, 02 Jan 2004 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/679001</guid>
    </item>
    <item>
      <title>FORWARD COLLISION WARNING REQUIREMENTS PROJECT: REFINING THE CAMP CRASH ALERT TIMING APPROACH BY EXAMINING "LAST-SECOND" BRAKING AND LANE CHANGE MANEUVERS UNDER VARIOUS KINEMATIC CONDITIONS</title>
      <link>https://trid.trb.org/View/643485</link>
      <description><![CDATA[This final report describes a follow-on study to the previous Crash Avoidance Metrics Partnership (CAMP) human factors work addressing Forward Collision Warning (FCW) timing requirements. This research extends this work by gathering not only "last-second" braking maneuver data, but also data from "last-second" steering (or lane-change) maneuvers.  Drivers performed last-second braking and steering maneuvers under instructions for "normal" or "hard" intensity responses under a wide variety of vehicle-to-vehicle kinematic scenarios.  This strategy of varying instruction during these last-second maneuvers was taken so that drivers' perceptions of "normal" and "non-normal" kinematics situations (or envelopes) could be properly identified and modeled for crash alert timing purposes. In addition, unlike the previous CAMP work that only examined lead vehicle stationary and lead vehicle braking scenarios, the current study also included scenarios where the lead vehicle was moving at a slower but constant speed prior to the last-second maneuver.  Results provided validation of the Required Deceleration Model developed in the prior CAMP FCW project.  In addition, a new model was developed, referred to as the "3-Tiered Inverse Time-To-Collision Model".  This promising model assumes the driver deceleration response (in response to the crash alert) is based on an inverse Time-To-Collision threshold that decreases linearly with speed.  One advantage of this model is that it requires only coarse (rather than accurate) knowledge of lead vehicle deceleration levels.]]></description>
      <pubDate>Wed, 04 Jun 2003 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/643485</guid>
    </item>
    <item>
      <title>PASSENGER VEHICLE CRASHES INTO STATIONARY LARGE TRUCKS: INCIDENCE AND POSSIBLE COUNTERMEASURES</title>
      <link>https://trid.trb.org/View/642590</link>
      <description><![CDATA[House Joint Resolution No. 23, 2002 Session of Virginia's General Assembly, requested that the Virginia Transportation Research Council and the Crash Investigation Team of Virginia Commonwealth University's Transportation Safety Training Center conduct a study of highway crashes involving trucks and other large vehicles stopped on the roadway or shoulder and struck in the rear.  The purpose of the study was to determine the spatial and perceptual factors, physiological elements, and ingredients that combine to cause or materially contribute to these crashes; how and why these crashes occur; and practical countermeasures to reduce the number and severity of these crashes.  To answer the question of how and why these crashes occur, Virginia crash data from 1997 through 2001 were analyzed.  In only a few crashes was a large truck stopped on the roadway or shoulder struck in the rear by a passenger vehicle.  Rear-end crashes in which the leading vehicle was stopped were more numerous, but single-vehicle roadway departure crashes into parked vehicles were more severe.  Environmental, roadway, and surface conditions had little influence.  The major contributing factor was driver inattention.  With regard to the psychological and perceptual factors contributing to these crashes, it is likely that large trucks are more conspicuous than other stopped vehicles because of their size, unique profile, and requirements for reflectorized tape.  However, large trucks stopped or parked continue to be struck in the rear by passenger vehicles.  The cause here is also driver inattention in several forms, none of which can be directly attributed to any particular crash without a detailed crash investigation.  As to possible countermeasures, two approaches stand out:  increasing driver attention and removing large trucks from the shoulder.  Existing methods for increasing driver attention include using infrastructure warning systems and continuous shoulder rumble strips.  Future improvements to driver attention are linked to technically advanced collision warning systems that will enter the marketplace before 2012 and provide an automatic warning to drivers of possible collisions.  Removing large trucks from the shoulder is more of a problem and is tied to the larger issue of the supply and demand for public and private commercial vehicle parking.  Short-term improvements include amending and strictly enforcing existing parking regulations, developing a pilot program to alert truck drivers of available parking facilities, and investigating the use of Virginia's weigh stations for large truck parking.  The long-term approach includes conducting studies designed to document the extent of large truck parking on the ramps and shoulders of Virginia's limited access highways, assessing the adequacy of large-truck parking statewide, and prioritizing locations with the greatest need for public and private development of large-truck parking facilities.]]></description>
      <pubDate>Wed, 09 Apr 2003 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/642590</guid>
    </item>
    <item>
      <title>CELL PHONE USE WHILE DRIVING IN NORTH CAROLINA: 2002 UPDATE REPORT</title>
      <link>https://trid.trb.org/View/642536</link>
      <description><![CDATA[This follow-on to an earlier study was carried out to further understanding regarding the safety implications of cellular telephone use while driving.  The study involved three separate tasks:  (1) a statewide telephone survey to gather information on cell phone use and user characteristics, along with drivers' opinions regarding the safety and potential regulation of cell phone use while driving; (2) an analysis of the characteristics of cell phone-related crashes, based on 452 cell phone crashes identified from an earlier computerized narrative search of North Carolina crash data; and (3) a supplementary data collection activity by the North Carolina State Highway Patrol to identify and report cell phone-related crashes occurring statewide over a two-month period.  The statewide telephone survey was conducted during the early summer of 2002 and targeted 500 users and 150 non-users of cell phones.  All participants were licensed North Carolina drivers aged 18 and older.  Key findings from the telephone survey include the following:  An estimated 58.8% of the state's licensed drivers have used a cell phone while driving; Cell phone use levels were highest among drivers in the 25-39 and 40-54 year age categories; Other demographic characteristics did not differ significantly for users versus non-users, although a higher proportion of users than non-users drove sport utility vehicles; The average reported time per day spent talking on a cell phone while driving was 14.5 minutes, while the median reported time was much lower at 5.0 minutes; One in four users reported having a hand-free device, but they did not always use the device when talking on their cell phones; Users generally perceived talking on cell phones while driving to be less distracting and less of a safety concern than did non-users.  To examine the characteristics of cell phone-related crashes, a computerized narrative search of all reported crashes occurring in the state from Jan. 1, 1996 through Aug. 31, 2000 resulted in the identification of 452 cell phone-related crashes. The characteristics of these crashes were compared with the nearly 1.1 million non-cell phone crashes occurring in the state during the same time period.  Results showed that:  Cell phone crashes were less likely than non-cell phone crashes to result in serious or fatal injury, were nearly twice as likely to involve rear-end collisions, and involved approximately equal proportions of ran-off-road and angle collisions; Cell phone crashes were somewhat more likely to occur during the mid-day or afternoon hours and to occur in urban areas, on local streets, and at roadway locations with no special feature; Compared to non-users, drivers who were using their cell phone at the tome of their crash were more likely to be male, under the age of 55, and driving a sport utility vehicle; The most commonly identified driver violations for cell phone users involved in crashes were failure to reduce speed, traffic signal violation, speeding, following too closely, and failure to yield.]]></description>
      <pubDate>Tue, 01 Apr 2003 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/642536</guid>
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