Analysis of the Contributory Factors to Accidents at Signalized Intersections using Generalized Estimating Equation with Negative Binomial Distribution

Ensuring safety on roadways and controlling conflicting and merging streams of traffic at signalized intersections has become a major concern for transportation engineers and road users globally and locally. Many factors contribute to accident occurrence at road segments and intersections with driver behavior being the major contributor. Other factors include those related to the vehicle and the road. The primary aim of this study is to understand the impact of different factors causing traffic accidents at signalized intersections. It also include developing a descriptive study of traffic accident data to show the variation with different factors at both intersections and roadway segments. To achieve this objectives, 22 signalized intersections and all roadways in Duhok city/Iraq were selected. Assessing the effects of geometric characteristics and driver behavior on safety performance of the sites have been achieved through observations of trends from graphs and use of appropriate advanced statistical analysis such as Generalized Estimating Equation (GEE) with NB distribution and log link function. The results show that approach width, driver inattention, red light running and surface moisture condition are the significant contributors to accident occurrence. The study results highlight the importance of driver education, police enforcement and appropriate geometric design of intersections to the reduction of accident occurrence

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

Highlighting dynamically loaded pavement sections with profile indices

The interaction between road surface roughness and heavy vehicles results in dynamic wheel loading (DWL), which increases pavement damage. The magnitude of DWL is dependent on the level of surface roughness and its characteristics and the properties and speeds of heavy vehicles. The measurement of DWL under normal operating conditions is costly, and the estimation of the resultant pavement damage is difficult because of the great variation in heavy vehicle fleet characteristics operating on the network. Additional damage caused by DWL is reflected in increased pavement deterioration over time. Deterioration is apparent in changes in the surface profile characteristics, which have a determining influence on dynamic loading and the degree of its spatial repeatability. The suitability of a number of profile indices as indicators of dynamically loaded pavement sections was assessed. Several regression models were developed with different profile indices used as predictors of different measures of pavement damage caused by DWL. The international roughness index and heavy articulated truck index were among the indices tested. The magnitudes of the simulated DWL were represented by such measures as dynamic load coefficient and dynamic aggregate force coefficient. This approach could help road authorities identify sections that are subject to high DWL and to take appropriate measures to reduce the impact. The heavy articulated truck index, measured with the dynamic aggregate force coefficient, proved to be the best predictor of pavement damage caused by DWL. rehabilitation treatments to control accelerated wear caused by DWL

Characterisation of anomalous pavement roughness data

Abstract not availabl

Assessment of network surfacing data of rural network of VicRoad

A technical report prepared for VicRoads, Melbourne, Victoria

The effect of long wavelength roughness on pavement damage, safety, user costs and comfort

Abstract not available

Process for setting intervention criteria and allocating budgets: literature review

This report addresses the first task (a literature review) of Austroads project AT1042 'Process for Setting Intervention Criteria and Allocating Budgets'. The report provides a review of the available published literature on multi-objective analysis techniques and their use in setting maintenance intervention criteria and allocating budgets. A multi-objective resource allocation model is proposed. It allows for trading off intervention criteria across the different assets to meet budget limits. The report includes background information on life cycle cost analysis, its data needs and use in setting maintenance intervention criteria. It also includes a review of current maintenance intervention criteria used by Australasian road authorities for a number of asset items and factors contributing to their variations

Feasibility of using high RAP contents in Hot Mix Asphalt

This paper provides a review of recent research findings on the design, properties and performance of asphalt mixes containing high percentages of Recycled Asphalt Pavement (RAP). The review covers both national and international research. The aim of this paper is to highlight the advantages and disadvantages of such practice, supported by field long term performance where possible. The reasons behind its limited application are also discussed and options for overcoming them are highlighted

Sustainable mobility for heavy freight vehicles

Mobilisation of heavy freight vehicles in a sustainable manner requires providing accessibility and a well-defined, safe and smooth road network that allows short travel times to minimise the carbon foot print of heavy transport system. Road surface roughness affects the comfort of the driver and increases user costs in terms of vehicle operating costs and travel time. Achieving a smooth road network requires adopting appropriate maintenance and rehabilitation strategies. The latter requires the use of appropriate intervention criteria in terms of intervention measures and treatments. This paper describes the development and validation of a profile-based roughness measure referred to as the Heavy Articulated Truck Index (HATI). HATI can be used to identify road sections providing poor ride quality for heavy transport operators. The effectiveness of HATI as a measure of pavement damage due to dynamic wheel loads is also investigated. Adopting HATI and the other diagnostic measures proposed herein help road authorities implement appropriate maintenance strategies to ensure the sustainability of their pavement assets and reduce emissions generated by heavy and light vehicles, in addition to providing acceptable level of service to all road users

Perception of low frequency vibrations by heavy vehicle drivers

A study was initiated to identify the levels and frequencies of heavy articulated vehicle body vibrations at which the drivers perceive the ride as uncomfortable. The study involved conducting a subjective assessment survey in which a panel of truck drivers were asked to rate the ride quality provided by a number of road sections with different surface roughness characteristics. The study's objective was achieved by correlating the mean panel ratings (MPRs) to road surface roughness contents in different one-third-octave bands of the roughness spectrum. The results showed that at 100 km/h, truck drivers object mainly to motions resulting from roughness excitations of the low frequency vibration modes of the truck body in the range 1.42 – 5.7 Hz. These results were validated by correlating MPRs with the levels of whole body vibrations measured on the driver's seat in a representative vehicle while traversing some test sections. MPRs were found to correlate well with the measured overall vibration total values and the likely comfort reactions to various magnitudes of overall vibration total values given by ISO 2631-1. The influence on MPRs of vehicle and driver related factors were also investigated and commented upon