Given $N$ cities and $R<N^2 - N$ directed (unidirectional/one way) roads does there exist a tour of all $N$ cities stopping at each city exactly once using the given roads (a Hamiltonian cycle)? This Hamiltonian cycle problem (HCP) is an NP-complete problem, for which there is no known polynomial time solution algorithm. The HCP has important practical applications, for example, to logistical p...

BACKGROUND Traffic exposure is a major contributor to ambient air pollution for people living close to busy roads. The relationship between traffic exposure and lung function remains inconclusive in adults. METHODS A cross-sectional study was conducted to investigate the association between traffic exposure and lung function in the Atherosclerosis Risk in Communities (ARIC) study, a community...

We live on an ever more-populous planet, pulsating with human-generated noises of every description. The most ubiquitous noisemaking structures we produce are trafficladen roads (Fig. 1), which already criss-cross much of the Earth and are projected to increase in length by some 25 million km by midcentury: enough to encircle the planet more than 600 times (1). For wildlife, the challenges of l...

BACKGROUND Road Traffic Crashes (RTCs) are major causes of morbidity and mortality in Nigeria. Few studies in Ibadan have focused on the distribution and determinants of RTC among long distance drivers. OBJECTIVE To describe the distribution of crashes by place, times of occurrence, characteristics of persons involved and identify associated factors. METHODS A cross-sectional study was carr...

Roads provide humans with a means of mobility between destinations, be it for transportation of goods and services or as a means of connecting with others. However, roads are also known to contribute toward a number of deleterious landscape processes, such as habitat destruction and fragmentation, pollution (e.g., chemical, noise and light) and animal mortality. Few studies however have investi...

BACKGROUND Heart failure (HF) is a significant source of morbidity and mortality among African Americans. Ambient air pollution, including from traffic, is associated with HF, but the mechanisms remain unknown. The objectives of this study were to estimate the cross-sectional associations between residential distance to major roadways with markers of cardiac structure: left ventricular (LV) mas...

Young drivers, especially males, have relatively more accidents than other drivers. Young driver accidents also have somewhat different characteristics to those of other drivers; they include single vehicle accidents involving loss of control; excess speed for conditions; accidents during darkness; accidents on single carriageway rural roads; and accidents while making cross-flow turns (i.e. tu...

BACKGROUND Epidemiologic studies indirectly suggest that air pollution accelerates atherosclerosis. We hypothesized that individual exposure to particulate matter (PM) derived from fossil fuel would correlate with plasma concentrations of oxidized low-density lipoprotein (LDL), taken as a marker of atherosclerosis. We tested this hypothesis in patients with diabetes, who are at high risk for at...