Air quality is a serious and worsening problem in the rapidly growing cities of sub-Saharan Africa (SSA). However, the lack of ambient monitoring data, and particularly urban roadside concentrations for particulate matter in SSA cities severely hinders our ability to describe temporal and spatial patterns of concentrations, characterize exposure–response relationships for key health outcomes, e...

In this paper, two-state Markov switching models are proposed to study accident frequencies. These models assume that there are two unobserved states of roadway safety, and that roadway entities (roadway segments) can switch between these states over time. The states are distinct, in the sense that in the different states accident frequencies are generated by separate counting processes (by sep...

Determining the influence scope of airflow disorder is an important problem after coal and gas outburst accidents in ventilation systems. This paper puts forward indexes disorder, including length excavation roadway, pressure, pressure difference air door, quantity auxiliary fan. Using orthogonal table L9 (34) numerical simulation method, characteristics reversal are studied, degree calculated ...

The Highway Safety Manual [HSM, 2010] recommends safety evaluations be performed before implementing any roadway treatment to predict the expected safety consequences. Safety consequences can be measured using crash prediction models, Crash Modification Factor (CMFs), or both. This paper develops a CMF to show the expected impact of red-light cameras (RLCs) on safety at signalized intersections...

In most of the developing countries, the metropolitan organizations do not assess the safety consequences of alternative transportation systems and one of the reasons is the lack of suitable methodology. The goal of this paper is to develop practical tools for assessing safety consequences of arterial roads in the context of long-term urban transportation plans in Dhaka city, the capital of Ban...

The design of Automated Highway Systems (AHS) involves the use of advancedtechnologies and automation to make the current transportation system more efficient interms of capacity, safety and pollution. The principal question is whether thesetechnologies will lead to any benefits in terms of safety, capacity and traffic flowcharacteristics as the degree of penetration in the curr...

In order to determine the rational width of coal pillars and study surrounding rock control technology gob side entry driving with a narrow pillar, this paper first calculates pillar according limit equilibrium theory; after that, lateral support pressure plastic zone development goaf is analyzed by numerical simulation reserved pillar; finally, through ring breaking deformation regulation entr...

Understanding injury severity patterns in roadway crashes is important not only from the view point of treating crash victims, but also for directing the crash avoidance efforts of traffic safety agencies and motor vehicle manufacturers. The factor that is most discussed in this context is vehicle incompatibility. However, there are other vehicle-, occupant-, and roadway-related factors, too, t...

The design of Automated Highway Systems (AHS) involves the use of advancedtechnologies and automation to make the current transportation system more efficient interms of capacity, safety and pollution. The principal question is whether thesetechnologies will lead to any benefits in terms of safety, capacity and traffic flowcharacteristics as the degree of penetration in the curr...