A New Model of Crash Severities Reportable to the MCMIS Crash File

The Motor Carrier Management Information system (MCMIS) Crash file has been developed by the Federal Motor Carrier Safety Administration (FMCSA) to serve as a census file of trucks and buses involved in traffic crashes meeting a specific crash severity threshold. Each state is responsible for identifying cases that meet the MCMIS Crash file criteria and reporting the required data through the SafetyNet system. The present report is an addition to three previous reports describing models to predict the number of crash involvements a state should be reporting. The model has been updated and changed over time as more data becomes available from additional states. In each state, the number of fatal involvements is well-known, so all states will start with a known quantity, the number of fatal truck and bus crash involvements. The new model also incorporates a rural/urban (RU) factor that accounts for the relative proportion of rural to urban truck travel in a state. In the new model, data from 16 states that provide all the information necessary to identify MCMIS-reportable cases were used. A log-linear model is fit to MCMIS data for the states that have information recorded for both fatal and nonfatal crashes. The model is then used to predict the number of nonfatal crashes for a new state in which the number of fatal crashes and the RU factor are known. Ninety percent prediction intervals provide a range of nonfatal crash values to be used for guidance. The new model provides more accurate prediction than previous models and is expected to be updated as data from additional states become availableFederal Motor Carrier Safety Administrationhttp://deepblue.lib.umich.edu/bitstream/2027.42/89595/1/102787.pd

The safety profile of work-related trucks

"Special report"This report is an investigation into the safety profile of work-related trucks which includes dump, garbage/refuse, tow/wrecker, cement mixer, utility, and many other single unit vocational trucks. Statistics are presented comparing work trucks to tractor semitrailers, straight truck vans, and passenger cars. Five years (1997-2000, 2002) of fatal crash counts are taken from the Trucks Involved in Fatal Accidents database. Fatal crash counts in 2002 for passenger cars are derived from the Fatality Analysis Reporting System data file. Vehicle miles traveled (VMT) data for trucks are taken from the 2002 Vehicle Inventory and Use Survey, while VMT data for passenger cars are derived from reports published by the Federal Highway Administration. Crash involvement rates per 100 million VMT are calculated and compared among different vehicle types. In addition, fatal crash statistics are presented comparing work trucks, straight truck vans, tractor semitrailers, and passenger cars with respect to road and environment characteristics, vehicle characteristics, and driver characteristics. Based on VIUS VMT, the average annual crash involvement rate for all trucks (class 3 and above) was 3.54. Dump trucks had the highest crash involvement rate (5.96). The rate for garbage/refuse trucks was 5.12, while the rate for tractor semitrailers was 3.63. Straight truck vans had one of the lowest rates (2.09). While fatal crash involvement rates for some of the work trucks appear to be high, aggregated rates do not take into account the kinds of roads that work trucks typically traveled on. Dump trucks accumulated 80% of travel on local trips (50 miles or less), while semitrailers accumulated only 15.8% of travel on local trips. After stratification by trip type, it is shown that rates for many work trucks are comparable to, and in some cases lower than, the rate for semitrailers. On trips greater than 50 miles the rates for dump trucks and garbage/refuse trucks were 2.90 and 1.90, respectively, while the rate for semitrailers was 3.29National Truck Equipment Association, Washington, D.C.http://deepblue.lib.umich.edu/bitstream/2027.42/13897/2/99204.pd

Tracking the use of onboard safety technologies across the truck fleet

Special ReportThe Transportation Safety Analysis and the Automotive Analysis Divisons at the University of Michigan Transportation Research Institute (UMTRI) initiated the Onboard Safety Technologies project in 2007, supported by FMCSA, to collect detailed information about the penetration of onboard safety technologies in the trucking fleet and future use of these technologies. The five technologies examined included: lane departure warning (LDWS), electronic stability control (ESC), forward and side collision warning (FCWS/SCWS), and vehicle tracking systems (TRACKING). Previous work in estimating the penetration of onboard safety technologies never approached the question of technology penetration by sampling the popluation of trucking companies. This project uses that approach through the use of a random sample survey of the entire fleet of trucking companies to measure current penetration, future use, and the advantages available to companies employing these technologies. The source for the sample was the 2007 Motor Carrier Management Information System (MCMIS) file. Interviews were also conducted with companies with high penetration of the technologies as well as system suppliers of the technologies, in order to gather more detailed information about usage and future technology direction. The results of the survey show the expected low levels of usage of LDWS, FCWS, and SCWS, slightly higher levels of usage of ESC, and much higher usage of TRACKING. Analysis shows higher usage related to larger company size. Company usage of these technologies is expected to double over the next five years. The main factors noted by participants for using the technologies that vary little among the technologies include: proven safety benefits of the technologies, positive feedback by drivers, driver improvement, improved safety culture, reduced cost of accidents, and insurance benefits. The interviews yielded important views about the cost advantages of usage, the difficulty of justifying the purchase of the technologies, alternatives to safety technologies, and the future of technology integration.Federal Motor Carrier Safety Administration, Washington, D.Chttp://deepblue.lib.umich.edu/bitstream/2027.42/91262/1/102868.pd

Truck mechanical condition and crashes in the large truck crash causation study

Special reportThis study examines the relationship of heavy truck mechanical condition and crash risk. The LTCCS presents an opportunity to examine in more detail than previously possible the relationship of vehicle condition to crash risk. The report includes a review of existing literature, a full analysis of the results of the post-crash truck inspections, and a series of logistic regression models to test the association of vehicle condition and crash role. Two specific hypotheses are tested: The first hypothesis is that trucks with defects and out of service conditions are statistically more likely to be in the role of precipitating a crash than trucks with no defects or out of service conditions. The second hypothesis is that defects in specific systems, such as the brake system, are associated with crash roles in which those systems are primary in crash avoidance, and that there is a physical mechanism that links the vehicle defect with the crash role. Post crash inspections showed that the condition of the trucks in the LTCCS is poor. Almost 55 percent of vehicles had one or more mechanical violations. Almost 30 percent had at least one out of service condition. Among mechanical systems, violations in the brake (36 percent of all) and lighting system (19 percent) were the most frequent. A brake OOS condition increased the odds of the truck assigned the critical reason (identifying the precipitating vehicle) by 1.8 times. Both HOS violations and log OOS increased by a larger amount—2.0 and 2.2 times respectively. In rear-end and crossing paths crashes, brake violations, especially related to adjustment, increased the odds of the truck being the striking vehicle by 1.8 times.Federal Motor Carrier Safety Administration, Washington, D.C.http://deepblue.lib.umich.edu/bitstream/2027.42/64999/1/102509.pd

Updated ratio of crash severities reportable to the MCMIS crash file

The Motor Carrier Management Information System (MCMIS) Crash file has been developed by the Federal Motor Carrier Safety Administration (FMCSA) to serve as a census file of trucks and buses involved in traffic crashes meeting a specific crash severity threshold. Each state is responsible for identifying cases that meet the MCMIS Crash file criteria and reporting the required data through the SafetyNet system. UMTRI has completed a set of evaluations of state reporting and found that reporting rates range from over 80 percent to less than 10. The present report provides an updated model to predict, given a known number of fatal involvements, the number of crash involvements a state should be reporting. Additional observations became available since the previous report. These observations are incorporated and the model re-estimated. In each state, the number of fatal involvements is well-known, so all states will start with a known quantity, the number of fatal truck and bus crash involvements. It is then hypothesized that the ratio of reportable crash severities, that is, the ratio of fatal involvements to nonfatal involvements, will apply across all the states. Data from 11 states (representing 13 observations) that provide all the information necessary to identify MCMIS-reportable cases were used. A weighted log-linear model is fit to MCMIS data for the states that have information recorded for both fatal and nonfatal crashes. The model is then used to estimate the number of nonfatal crashes for a new state in which only the number of fatal crashes is known. Prediction intervals are presented.Federal Motor Carrier Safety Administrationhttp://deepblue.lib.umich.edu/bitstream/2027.42/61822/1/102175.pd

Evaluation of the CSA 2010 operational model test

In accordance with its primary mission to reduce crashes, injuries, and fatalities involving large trucks and buses, the Federal Motor Carrier Safety Administration (FMCSA) initiated the Comprehensive Safety Analysis 2010 (CSA 2010) Operational Model Test. The program focused on initiating contact with more carriers and drivers, development of a new measurement system to replace Motor Carrier Safety Status Measurement System (SafeStat), application of a wider range of progressive interventions to correct high-risk behavior, and more efficient use of Agency resources. The test ran for 29 months from February 2008 through June 2010. This report is an evaluation of the CSA 2010 Operational Model Test. The evaluation focuses on key components of the model. In particular, measurement system thresholds exceeded in type and frequency, interventions received in type and frequency, and the number and percentage of carriers touched under the new model are calculated and reported. Intervention cycles and patterns are explored and effectiveness of interventions is determined by comparing test carriers that received CSA 2010 interventions to control carriers that did not. Costs to the agency of performing interventions are investigated and compared to the current process of conducting compliance reviews (CRs). The new Safety Measurement System (SMS) that is used to rank a carrier’s safety performance in the seven Behavior Analysis and Safety Improvement Categories (BASICs) is evaluated by assessing associations between percentile scores and crash rates. Comparisons with the current model under SafeStat are reported and quality of the Motor Carrier Management Information System (MCMIS) data files is discussed. Finally, results from a survey completed by field staff participating in the Operational Model Test is presented to determine which aspects of CSA 2010 worked well and which did not.U.S. DOT Office of Analysis, Research, and Technologyhttp://deepblue.lib.umich.edu/bitstream/2027.42/86185/1/102763.pd

Bus operator types and driver factors in fatal bus crashes: Results from the buses involved in fatal accidents survey

The Transportation Safety Analysis Division at the University of Michigan Transportation Research Institute (UMTRI) initiated the Buses Involved in Fatal Accidents (BIFA) project in 2000 to collect more detailed information about buses involved in fatal crashes. The BIFA project is supported by the Federal Motor Carrier Safety Administration. Previous work using BIFA data showed significant differences between different bus operations in terms of crash types, when and where the crashes occurred, the incidence of bus driver error, and previous driver record of the drivers. Using BIFA data for 1999-2005, the present study focuses on factors associated with driver errors in fatal bus crashes involving different bus operator types. Five different carrier types are identified: School, transit, intercity, charter/tour, and “other” bus operators. There are substantial differences between these carrier types that are reflected in rates of bus driver errors in crashes and in the previous driving record of the bus drivers. Many factors are identified that are associated with driver error, including bus operation type, age, sex, hours driving, trip type, method of compensation, and previous driving record. A logistic regression model was used to model the probability of driver error. Bus operation type, previous violations, and previous crashes were significant parameters in the model. The other factors were not significant.Federal Motor Carrier Safety Administrationhttp://deepblue.lib.umich.edu/bitstream/2027.42/61823/1/102176.pd

Commercial medium tire debris study

Trucking fleets and owners of commercial vehicles utilize both new and retread tires on their vehicles in the United States. Retread tires are used primarily for the cost advantage they provide over a similar new tire. Despite the advantages that retreaded tires may bring, public perception is that retread tires are less safe than new tires as evidenced by the amount of tire debris frequently found on the sides of U.S. Interstate highways. During summer 2007, the University of Michigan Transportation Research Institute (UMTRI) under a subcontract from Virginia Tech Transportation Institute (VTTI) collected and studied truck tire debris and discarded tire casings from five sites in the United States. A random sample (totaling 1,496 items) of the tire debris/casings collected was analyzed to determine the probable cause of failure and its original equipment or retread status. This report presents the methodology and results from this investigation into the underlying causes of truck tire failures and gives an overview of the crash safety problem associated with heavy-truck tire failures. Also, background information on the manufacture of a truck tire, the truck tire retread industry, tire failure modes, industry stakeholder perspectives, an overview of other previous tire debris studies, conclusions, and recommendations for topics for further research are given.National Highway Traffic Safety, Administration Office of Applied Vehicle Safety Researchhttp://deepblue.lib.umich.edu/bitstream/2027.42/61517/1/102117.pd

Safety benefits of stability control systems for tractor- semitrailers

This study was conducted by the University of Michigan Transportation Research Institute (UMTRI) under a Cooperative Agreement between NHTSA and Meritor WABCO to examine the performance of electronic stability control (ESC) systems, and roll stability control (RSC) systems for heavy-truck tractor-semitrailers. The study is based on the analysis of independent crash datasets using engineering and statistical techniques to estimate the probable safety benefits of stability control technologies for 5-axle tractor-semitrailer vehicles. The conventional approach for assessing the safety benefits of vehicle technologies is to analyze crash datasets containing data on the safety performance of vehicles equipped with the technology of interest. Because the deployment of the stability technologies for large trucks is in its infancy, national crash databases do not yet have a sufficient amount of factual data that can be directly linked to the performance of the technology. Therefore a novel method of examining the potential benefits of these systems was used. Crash scenarios that could likely benefit from the technologies were selected from national crash databases and the probable effectiveness of each technology was estimated. The analysis in this study did not have the advantage of examining representative crash datasets that contain identifiable data from vehicles equipped with the technology. Therefore, the analysis was based on probable outcome estimates derived from hardware-in-the-loop simulation, field test experience, expert panel assessment, and fleet crash data and these methods were used to estimate the safety benefits from the national crash data population.National Highway Traffic Safety Administration, Office of Applied Vehicle Safety Researchhttp://deepblue.lib.umich.edu/bitstream/2027.42/64283/1/102397.pd

Versatile Diphosphine Chelators for Radiolabeling Peptides with ^99mTc and ⁶⁴Cu

We have developed a diphosphine (DP) platform for radiolabeling peptides with 99mTc and 64Cu for molecular SPECT and PET imaging, respectively. Two diphosphines, 2,3-bis(diphenylphosphino)maleic anhydride (DP Ph) and 2,3-bis(di- p-tolylphosphino)maleic anhydride (DP Tol), were each reacted with a Prostate Specific Membrane Antigen-targeted dipeptide (PSMAt) to yield the bioconjugates DP Ph-PSMAt and DP Tol-PSMAt, as well as an integrin-targeted cyclic peptide, RGD, to yield the bioconjugates DP Ph-RGD and DP Tol-RGD. Each of these DP-PSMAt conjugates formed geometric cis/ trans-[MO 2(DP X-PSMAt) 2] + (M = 99mTc, 99gTc, natRe; X = Ph, Tol) complexes when reacted with [MO 2] + motifs. Furthermore, both DP Ph-PSMAt and DP Tol-PSMAt could be formulated into kits containing reducing agent and buffer components, enabling preparation of the new radiotracers cis/ trans-[ 99mTcO 2(DP Ph-PSMAt) 2] + and cis/ trans-[ 99mTcO 2(DP Tol-PSMAt) 2] + from aqueous 99mTcO 4 - in 81% and 88% radiochemical yield (RCY), respectively, in 5 min at 100 °C. The consistently higher RCYs observed for cis/ trans-[ 99mTcO 2(DP Tol-PSMAt) 2] + are attributed to the increased reactivity of DP Tol-PSMAt over DP Ph-PSMAt. Both cis/ trans-[ 99mTcO 2(DP Ph-PSMAt) 2] + and cis/ trans-[ 99mTcO 2(DP Tol-PSMAt) 2] + exhibited high metabolic stability, and in vivo SPECT imaging in healthy mice revealed that both new radiotracers cleared rapidly from circulation, via a renal pathway. These new diphosphine bioconjugates also furnished [ 64Cu(DP X-PSMAt) 2] + (X = Ph, Tol) complexes rapidly, in a high RCY (&gt;95%), under mild conditions. In summary, the new DP platform is versatile: it enables straightforward functionalization of targeting peptides with a diphosphine chelator, and the resulting bioconjugates can be simply radiolabeled with both the SPECT and PET radionuclides, 99mTc and 64Cu, in high RCYs. Furthermore, the DP platform is amenable to derivatization to either increase the chelator reactivity with metallic radioisotopes or, alternatively, modify the radiotracer hydrophilicity. Functionalized diphosphine chelators thus have the potential to provide access to new molecular radiotracers for receptor-targeted imaging. </p