From Empirical Bayes to Full Bayes: Methods for Analysing Traffice Safety Data, October 25, 2004

Traffic safety engineers are among the early adopters of Bayesian statistical tools for analyzing crash data. As in many other areas of application, empirical Bayes methods were their first choice, perhaps because they represent an intuitively appealing, yet relatively easy to implement alternative to purely classical approaches. With the enormous progress in numerical methods made in recent years and with the availability of free, easy to use software that permits implementing a fully Bayesian approach, however, there is now ample justification to progress towards fully Bayesian analyses of crash data. The fully Bayesian approach, in particular as implemented via multi-level hierarchical models, has many advantages over the empirical Bayes approach. In a full Bayesian analysis, prior information and all available data are seamlessly integrated into posterior distributions on which practitioners can base their inferences. All uncertainties are thus accounted for in the analyses and there is no need to pre-process data to obtain Safety Performance Functions and other such prior estimates of the effect of covariates on the outcome of interest. In this slight, fully Bayesian methods may well be less costly to implement and may result in safety estimates with more realistic standard errors. In this manuscript, we present the full Bayesian approach to analyzing traffic safety data and focus on highlighting the differences between the empirical Bayes and the full Bayes approaches. We use an illustrative example to discuss a step-by-step Bayesian analysis of the data and to show some of the types of inferences that are possible within the full Bayesian framework.

Signing on Very Low Volume Rurd Roads Iowa DOT Project HR-262, July, 1984

Research was undertaken to define an appropriate level of use of traffic control devices on rural secondary roads that carry very low traffic volumes. The goal of this research was to improve the safety and efficiency of travel on the rural secondary road system. This goal was to be accomplished by providing County Engineers with guidance concerning the cost-effective use of traffic control devices on very low volume rural roads. A further objective was to define the range of traffic volumes on the roads for which the recommendations would be appropriate. Little previous research has been directed toward roads that carry very low traffic volumes. Consequently, the factual input for this research was developed by conducting an inventory of the signs and markings actually in use on 2,069 miles of rural road in Iowa. Most of these roads carried 15 or fewer vehicles per day. Additional input was provided by a survey of the opinions of County Engineers and Supervisors in Iowa. Data from both the inventory and the opinion survey indicated a considerable lack of uniformity in the application of signs on very low volume rural roads. The number of warning signs installed varied from 0.24 per mile to 3.85 per mile in the 21 counties in which the inventory was carried out. The use of specific signs not only varied quite widely among counties but also indicated a lack of uniform application within counties. County officials generally favored varying the elaborateness of signing depending upon the type of surface and the volume of traffic on different roads. Less elaborate signing would be installed on an unpaved road than on a paved road. A concensus opinion was that roads carrying fewer than 25 vehicles per day should have fewer signs than roads carrying higher volumes. Although roads carrying 0 to 24 vehicles per day constituted over 24% of the total rural secondary system, they carried less than 3% of the total travel on that system. Virtually all of these roads are classified as area service roads and would thus be expected to carry only short trips primarily by local motorists. Consequently, it was concluded that the need for warning signs rarely can be demonstrated on unpaved rural roads with traffic volumes of fewer than 25 vehicles per day. It is recommended that each county designate a portion of its roads as an Area Service Level B system. All road segments with very low traffic volumes should be considered for inclusion in this system. Roads included in this system may receive a lesser level of maintenance and a reduced level of signing. The county is also afforded protection from liability arising from accidents occurring on roads designated as part of an Area Service Level B system. A uniform absence of warning signs on roads of this nature is not expected to have any discernible effect on the safety or quality of service on these very low volume roads. The resources conserved may be expended more effectively to upgrade maintenance and traffic control on roads carrying higher volumes where the beneficial effect on highway safety and service will be much more consequential.

Long-Term Safety of Canakinumab in Patients with Gouty Arthritis.

Background/Purpose: Gouty arthritis (GA) is a chronic inflammatory disease. Targeting the inflammatory pathway through IL-1_ inhibition with canakinumab (CAN) may provide significant long-term benefits. CAN safety versus triamcinolone acetonide (TA) over initial 24 weeks (blinded study) for patients (pts) with history of frequent attacks (_3 in year before baseline) was reported earlier from core (_-RELIEVED [_-REL] and _-REL-II) and first extension (E1) studies1. Herein we present full 18-month long-term CAN safety data, including open-label second extension (E2) studies. Methods: GA pts completing _-REL E1 and _-REL-II E1 studies1 were enrolled in these 1-year, open-label, E2 studies. All pts entering E2, whether randomized to CAN or TA, received CAN 150 mg sc on demand upon new attack. Data are presented only for pts randomized to CAN, and are reported cumulatively, i.e. including corresponding data from previously reported core and E1 studies. Long-term safety outcomes and safety upon re-treatment are presented as incidence rate per 100 patient-years (pyr) of study participation for AEs and SAEs. Deaths are reported for all pts (randomized to CAN or TA). Selected predefined notable laboratory abnormalities are shown (neutrophils, platelets, liver and renal function tests). Long-term attack rate per year is also provided. Results: In total, 69/115 (60%) and 72/112 (64.3%) of the pts randomized to CAN in the two core studies entered the two E2 studies, of which 68 and 64 pts, respectively completed the E2 studies. The 2 study populations had differing baseline comorbidity and geographic origin. Lab data (not time adjusted) for neutropenia appears worse after retreatment in _-REL E2, and deterioration of creatinine clearance appears worse after retreatment (Table 1). The time-adjusted incidence rates for AEs were 302.4/100 pyr and 360/100 pyr, and for SAEs were 27.9/100 pyr and 13.9/100 pyr in _-REL E2 and _-REL-II E2 respectively (Table 1). The time-adjusted incidence rates of any AEs, infection AEs, any SAEs, and selected SAEs before and after re-treatment are presented in Table 1. Incidence rates for AEs and SAEs declined after re-treatment, with the exception of SAEs in _-REL-II E2, which increased from 2.9/100 pyr to 10.9/100 pyr (no infection SAEs after retreatment in _-REL-II E2, and other SAEs fit no special pattern). In the total safety population (N_454, core and all extensions), there were 4 deaths, 2 in the core studies previously reported1 and 2 during the _-REL E2 study (one patient in the CAN group died from pneumonia; one patient in the TA group who never received CAN died of pneumococcal sepsis). None of the deaths was suspected by investigators to be study drug related. The mean rates of new attacks per year on CAN were 1.21 and 1.18 in _-REL E2 and in _-REL-II E2. Conclusion: The clinical safety profile of CAN upon re-treatment was maintained long-term with no new infection concerns

Interstate 74 Quad Cities Corridor Study Scott County, Iowa and Rock Island County, Illinois Project Number IM-74-1(122)0-13-82 FHWA-IOWA-EIS-09-01-F, February 2009

The Federal Highway Administration (FHWA) and the Iowa and Illinois Departments of Transportation (Iowa DOT and IDOT) have identified the Selected Alternative for improving Interstate 74 (I-74) from its southern terminus at Avenue of the Cities (23rd Avenue) in Moline, Illinois to its northern terminus one mile north of the I-74 interchange with 53rd Street in Davenport, Iowa. The Selected Alternative identified and discussed in this Record of Decision is the preferred alternative identified in the Final Environmental Impact Statement (FEIS). The purpose of the proposed improvements is to improve capacity, travel reliability, and safety along I-74 between its termini, and provide consistency with local land use planning goals. The need for the proposed improvements to the I-74 corridor is based on a combination of factors related to providing better transportation service and sustaining economic development.

Evaluation of Safety Treatments for Roadside Culverts: TR-517, April 24, 2009

Roadside cross-drainage culverts have been found to impact vehicle accident injury levels. Designers have commonly used three safety treatments to protect errant drivers from culvert accidents. These treatments have included: culvert extension, guardrail installation and grating. In order to define which safety treatment is the most appropriate, benefit-cost analysis has used accident cost reduction to estimate societal gains earned by using any safety treatment. The purpose of this study was to estimate accident costs for a wide range of roadway and roadside characteristics so that designers can calculate benefit/cost ratios for culvert safety treatment options under any particular scenario. This study began with conducting a parametric study in order to find variables which have significant impact on accident cost changes. The study proceeded with highway scenario modeling which included scenarios with different values for combinations of roadway and roadside variables. These variables were chosen based upon findings from the parametric study and their values were assigned based upon highway classification. This study shows that the use of different culvert safety treatments should be flexible to roadway and roadside characteristics. It also shows that culvert extension and grating were the safety treatments found to produce the lowest accident costs for all highway scenarios modeled. Therefore, it is believed that the expanded adoption of culvert extension and culvert grates can improve overall highway safety.

Roadway Lighting and Safety: Phase II – Monitoring Quality, Durability and Efficiency, November 2011

This Phase II project follows a previous project titled Strategies to Address Nighttime Crashes at Rural, Unsignalized Intersections. Based on the results of the previous study, the Iowa Highway Research Board (IHRB) indicated interest in pursuing further research to address the quality of lighting, rather than just the presence of light, with respect to safety. The research team supplemented the literature review from the previous study, specifically addressing lighting level in terms of measurement, the relationship between light levels and safety, and lamp durability and efficiency. The Center for Transportation Research and Education (CTRE) teamed with a national research leader in roadway lighting, Virginia Tech Transportation Institute (VTTI) to collect the data. An integral instrument to the data collection efforts was the creation of the Roadway Monitoring System (RMS). The RMS allowed the research team to collect lighting data and approach information for each rural intersection identified in the previous phase. After data cleanup, the final data set contained illuminance data for 101 lighted intersections (of 137 lighted intersections in the first study). Data analysis included a robust statistical analysis based on Bayesian techniques. Average illuminance, average glare, and average uniformity ratio values were used to classify quality of lighting at the intersections.

Road Safety Audit for the Intersection of US 59 and IA 9 in Osceola County, Iowa Final Report, March 2012

The Iowa Department of Transportation (DOT) requested a road safety audit (RSA) of the US 59/IA 9 intersection in northwestern Iowa, just south of the Minnesota border, to assess intersection environmental issues and crash history and recommend appropriate mitigation to address the identified safety issues at the intersection. Although the number of crashes at the location has not been significantly higher than the statewide average for similar intersections, the severity of these crashes has been of concern. This RSA was unique in that it included intersection video observation and recorded traffic conflict data analysis, along with the daylight and nighttime field reviews. This report outlines the findings and recommendations of the RSA team for addressing the safety concerns at this intersection.

Report on the Iowa Department of Public Safety for the year ended June 30, 2011

Report on the Iowa Department of Public Safety for the year ended June 30, 2011

Immunogenicity and safety of an intradermal boosting strategy for vaccination against influenza in lung transplant recipients.

The immunogenicity of influenza vaccine is suboptimal in lung transplant recipients. Use of a booster dose and vaccine delivery by the intradermal rather than intramuscular route may improve response. We prospectively evaluated the immunogenicity and safety of a 2-dose boosting strategy of influenza vaccine. Sixty lung transplant recipients received a standard intramuscular injection of the 2006-2007 inactivated influenza vaccine, followed 4 weeks later by an intradermal booster of the same vaccine. Immunogenicity was assessed by measurement of geometric mean titer of antibodies after both the intramuscular injection and the intradermal booster. Vaccine response was defined as 4-fold or higher increase of antibody titers to at least one vaccine antigen. Thirty-eight out of 60 patients (63%) had a response after intramuscular vaccination. Geometric mean titers increased for all three vaccine antigens following the first dose (p < 0.001). However, no significant increases in titer were observed after the booster dose for all three antigens. Among nonresponders, 3/22 (13.6%) additional patients responded after the intradermal booster (p = 0.14). The use of basiliximab was associated with a positive response (p = 0.024). After a single standard dose of influenza vaccine, a booster dose given by intradermal injection did not significantly improve vaccine immunogenicity in lung transplant recipients.

School Bus Safety Study: Kadyn’s Law, December 2012

In 2012, the Iowa legislature passed a bill for an act relating to school bus safety, including providing penalties for failure to obey school bus warning lamps and stop signal arms, providing for a school bus safety study and administrative remedies, and making an appropriation. The bill, referred to as Iowa Senate File (SF) 2218 or “Kadyn’s Law,” became effective March 16, 2012. A multiagency committee addressed three specific safety study elements of Kadyn’s Law as follows: * Use of cameras mounted on school buses to enhance the safety of children riding the buses and aid in enforcement of motor vehicle laws pertaining to stop-arm violations * Feasibility of requiring school children to be picked up and dropped off on the side of the road on which their home is located * Inclusion of school bus safety as a priority in driver training curriculum This report summarizes the findings for each of these topics.

Genetic polymorphisms and drug interactions modulating CYP2D6 and CYP3A activities have a major effect on oxycodone analgesic efficacy and safety.

BACKGROUND AND PURPOSE: The major drug-metabolizing enzymes for the oxidation of oxycodone are CYP2D6 and CYP3A. A high interindividual variability in the activity of these enzymes because of genetic polymorphisms and/or drug-drug interactions is well established. The possible role of an active metabolite in the pharmacodynamics of oxycodone has been questioned and the importance of CYP3A-mediated effects on the pharmacokinetics and pharmacodynamics of oxycodone has been poorly explored. EXPERIMENTAL APPROACH: We conducted a randomized crossover (five arms) double-blind placebo-controlled study in 10 healthy volunteers genotyped for CYP2D6. Oral oxycodone (0.2 mg x kg(-1)) was given alone or after inhibition of CYP2D6 (with quinidine) and/or of CYP3A (with ketoconazole). Experimental pain (cold pressor test, electrical stimulation, thermode), pupil size, psychomotor effects and toxicity were assessed. KEY RESULTS: CYP2D6 activity was correlated with oxycodone experimental pain assessment. CYP2D6 ultra-rapid metabolizers experienced increased pharmacodynamic effects, whereas cold pressor test and pupil size were unchanged in CYP2D6 poor metabolizers, relative to extensive metabolizers. CYP2D6 blockade reduced subjective pain threshold (SPT) for oxycodone by 30% and the response was similar to placebo. CYP3A4 blockade had a major effect on all pharmacodynamic assessments and SPT increased by 15%. Oxymorphone C(max) was correlated with SPT assessment (rho(S)= 0.7) and the only independent positive predictor of SPT. Side-effects were observed after CYP3A4 blockade and/or in CYP2D6 ultra-rapid metabolizers. CONCLUSIONS AND IMPLICATIONS: The modulation of CYP2D6 and CYP3A activities had clear effects on oxycodone pharmacodynamics and these effects were dependent on CYP2D6 genetic polymorphism.

Rockfall characterisation and structural protection: A review

Rockfall is an extremely rapid process involving long travel distances. Due to these features, when an event occurs, the ability to take evasive action is practically zero and, thus, the risk of injury or loss of life is high. Damage to buildings and infrastructure is quite likely. In many cases, therefore, suitable protection measures are necessary. This contribution provides an overview of previous and current research on the main topics related to rockfall. It covers the onset of rockfall and runout modelling approaches, as well as hazard zoning and protection measures. It is the aim of this article to provide an in-depth knowledge base for researchers and practitioners involved in projects dealing with the rockfall protection of infrastructures, who may work in the fields of civil or environmental engineering, risk and safety, the earth and natural sciences.

Rural Expressway Intersection Safety Toolbox Desktop Reference, June 17, 2011

This document is intended to be a guide for planning-level decisions concerning safety issues and subsequent potential improvements at rural expressway intersections. It is NOT a design guide. It simply presents the gamut of safety treatment options and available strategies that have been employed in an attempt to reduce the number and severity of collisions at unsignalized rural expressway intersections.