The effects of driver factors and sign design features on the comprehensibility of traffic signs

PROBLEM: This paper addresses the effects of driver factors and sign design features on the comprehensibility of traffic signs. METHODS: A survey was designed to capture subjects' personal particulars, ratings on sign features, and comprehension scores, and then administered to 109 Hong Kong full driving license holders. RESULTS: Years with driving license and education level were significant predictors of sign comprehensibility. Contrary to expectation, the driver factors of age group, years of active driving, hours of driving, last time driving, driving frequency, and non-local driving experience had no effect on comprehension performance. Sign familiarity was correlated with comprehension score for licensed drivers, whereas sign concreteness, simplicity, and meaningfulness were not. IMPACT ON INDUSTRY: The results of this study provide useful guidelines for designing more user-friendly traffic signs in the future. It identified particular driver groups who lacked good understanding of traffic signs, and this information may assist the relevant organizations to better allocate traffic training resources, and better target future studies of traffic sign comprehension.     

Perceptions of implied hazard for visual and auditory alerting signals

Visual and auditory alerts are increasingly important and have many applications, particularly in the presentation of hazard information in transportation and many industrial systems. This paper is concerned with the factors that govern the relative effectiveness of alerting signals involving various combinations of visual and auditory signals. The visual variables were colour, flash rate, and flash mode, combined with or without an auditory alarm. It was found that the subjects associated different levels of hazard with different alerting light colours, flash rates, flashing modes, and with combinations of auditory and visual alerts. A red flashing light was perceived as the most effective hazard warning colour, with yellow and blue warning lights indicative of less hazardous situations. The faster the flash rate, the greater is the hazard perceived. A flash rate of 60 fpm (flashes per minute) was not as effective as the rates of 180 and 240 fpm, and 240 fpm was the most effective. This implies that hazard warning signal should flash at well above 60 fpm. Having a breakup in the flashing pattern so as to provide a double or triple flash mode also increases the effectiveness of the signal. There were significant interactions between the alert variables used. The difference in perceived hazard levels for the colours blue and yellow were statistically non significant, but blue was more effective in conveying hazard message than yellow at the high flash rates. When accompanied with auditory alarms, blue and yellow were perceived to convey the same perception level of hazard as red without auditory alarms. The effect of colour on perceived hazard was also found to vary with flash mode. As compared to either visual signal alone or a visual signal with other types of acoustic alarms, a siren type of auditory alarm was found more effective for eliciting perception of hazards. There was evidence that presenting alerting signal in triple-flash mode and at high flash rate could be annoying and might not help improving hazard awareness.     

Using urban man-made ponds to reconstruct a 150-year history of air pollution in northwest England

A regional pollution history has been reconstructed for the borough of Halton (northwest England) from four urban ponds in north Cheshire and south Merseyside, using environmental analyses of lake sediment stratigraphies. Mineral magnetism, geochemistry and radiometric dating have produced profiles of pollution characteristics dating from the mid-nineteenth century to present day. These pollution profiles reflect the atmospheric deposition of a range of pollutants over 150 years of intensified industry. Distinct phases of pollution deposition and characteristics are identified reflecting: (1) intensification of industry in the nineteenth century; (2) expansion of industry during the twentieth century; (3) post 1956 Clean Air Acts. This work promotes the potential use of these pollution archives for use in epidemiology to better understand links between human health and environmental pollution, especially for diseases with long latency times, where retrospective pollution exposure assessments are important.     

Evaluating the effects of foraging habitat restoration on shorebird reproduction: the importance of performance criteria and comparative design

Coastal development and engineering projects preclude ecosystem processes that provide habitat for beach nesting birds. Management for coastal species may depend on actions that attempt to restore important habitat features and mitigate disturbance effects. However, species response to restoration or other management actions may be difficult to predict or measure. At Jones Beach State Park, on Long Island, New York, a 0.49 ha restoration project provided moist substrate foraging habitat for breeding Piping Plovers (Charadrius melodus) from 2002 to 2005. We examined whether foraging habitat restoration affected Piping Plover breeding population size, productivity, and fledgling production within 300 m of the restoration site. We found a positive relationship between habitat restoration and the number of fledglings produced per year. However, foraging habitat restoration did not significantly increase the number of Plover pairs breeding at Jones Beach. Our ability to evaluate restoration effects on Plovers depended on: 1) use of multiple performance criteria; 2) a design that allowed comparison of pre- and post-restoration data; and 3) a spatial control that allowed comparison of similar areas that were near and far from the restoration site. Despite the small size of the restoration project, there were measurable benefits to Plovers, indicating that foraging habitat restoration may be an effective tool for species recovery.     

Evaluating the impact of interdisciplinary networking in environmental geochemistry and health: reviewing SEGH conferences and workshops

The Society for Environmental Geochemistry and Health (SEGH) is a forum for multidisciplinary interaction relating the geochemical environment to health. With national funding, SEGH identified collaborative opportunities through the MULTITUDE series of workshops (2007–2011). We reviewed the meetings by electronic questionnaire (39?% response). Smaller meetings saw most returning delegates, suggesting networking and personal interaction is a key positive feature of SEGH; 31?% of practitioners and 25?% of academics participated in more than one meeting. Collaboration between SEGH participants resulted in joint funding (13 academics, 4 practitioners, 1 other) and joint papers (19, 5, 3). Evidence of behavioural change was seen in comments in five themes regarding the impacts of the conferences: support for current direction; impact on education practice (academics); new approaches; networking; multidisciplinary work. Multidisciplinary meetings and resulting networking were seen as having real value by many respondents, who encouraged further active pursuit of these activities. SEGH is eager to continue these activities which transform research, education and practice, resulting in a better understanding of the structure and processes comprising the broad geochemical environment on health. Comments showed the value and strength of small, well-organised conferences, bringing together a mixed group of disciplines, both research and applied, in a relaxed atmosphere. The absence of serious negative critique along with clear, positive comments suggests that there is a substantial level of support for, and even pleasure in, SEGH multidisciplinary conferences and workshops over the past years. It is encouraging that annual European conferences are viewed as such a positive achievement.     

Levels of Lead in Urban Soils from Selected Cities in a Central Region of the Philippines (7 pp)

Background Aims, and Scope. Lead (Pb) is a naturally occurring element that poses environmental hazards when present at elevated concentration. It is being released into the environment because of industrial uses and from the combustion of fossil fuels. Hence, Pb is ubiquitous throughout global ecosystems. The existence of potentially harmful concentrations of Pb in the environment must be given full attention. Emissions from vehicles are major source of environmental contamination by Pb. Thus, it becomes imperative that concentrations of Pb and other hazardous materials in the environment not only in the Philippines, but elsewhere in the world be adequately examined in order that development of regulations and standards to minimize risk associated with these materials in urban areas is continued. The objectives of this study were: (1) to determine the levels of Pb in soil from selected urbanized cities in central region of the Philippines; (2) to identify areas with soil Pb concentration values that exceed estimated natural concentrations and allowable limits; and (3) to determine the possible sources that contribute to elevated soil Pb concentration (if any) in the study area. Methods This study was limited to the determination of Pb levels in soils of selected urbanized cities located in central region in the Philippines, namely: Site 1 – Tarlac City in Tarlac; Site 2 – Cabanatuan City in Nueva Ecija; Site 3 – Malolos City in Bulacan; Site 4 – San Fernando City in Pampanga; Site 5 – Balanga City in Bataan; and Site 6 – Olongapo City in Zambales. Soil samples were collected from areas along major thoroughfares regularly traversed by tricycles, passenger jeepneys, cars, vans, trucks, buses, and other motor vehicles. Soil samples were collected from five sampling sites in each of the study areas. Samples from the selected sampling sites were obtained approximately 2 to 3 meters from the road. Analysis of the soil samples for Pb content was conducted using an atomic absorption spectrophotometer. This study was conducted from 2003 to 2004. Since this study assumed that vehicular emission is the major source of Pb contamination in urban soil, other information which the researchers deemed to have bearing on the study were obtained such as relative quantity of each gasoline type disposed of in each city within a given period and volume of traffic in each sampling site. A survey questionnaire for gasoline station managers was prepared to determine the relative quantity of each fuel type (diesel, regular gasoline, premium gasoline, and unleaded gasoline) disposed of or sold within a given period in each study area. Results and Discussion Analysis of soil samples for Pb content showed the presence of Pb in all the soil samples collected from the 30 sampling sites in the six cities at varying concentrations ranging from 1.5 to 251 mg kg–1. Elevated levels of Pb in soil (i.e. greater than 25 mg kg–1 Pb) were detected in five out of the six cities investigated. Site 4 recorded the highest Pb concentration (73.9 ± 94.4 mg kg–1), followed by Site 6 (56.3 ± 17.1 mg kg–1), Site 3 (52.0 ± 33.1 mg kg–1), Site 5 (39.3 ± 19.0 mg kg–1), and Site 2 (38.4 ± 33.2 mg kg–1). Soil Pb concentration in Site 1 (16.8 ± 12.2 mg kg–1) was found to be within the estimated natural concentration range of 5 to 25 mg kg–1. Site 1 registered the least Pb concentration. Nonetheless, the average Pb concentration in the soil samples from the six cities studied were all found to be below the maximum tolerable limit according to World Health Organization (WHO) standards. The high Pb concentration in Site 4 may be attributed mainly to vehicular emission. Although Site 4 only ranked 3rd in total volume of vehicles, it has the greatest number of Type B and Type C vehicles combined. Included in these categories are diesel trucks, buses, and jeepneys which are considered the largest contributors of TSP (total suspended particles) and PM10 (particulate matter less than 10 microns) emissions. Conclusion Only one (San Juan in Site 4) of the thirty sampling sites recorded a Pb concentration beyond the WHO permissible limit of 100 mg kg–1. San Juan in Site 4 had a Pb concentration of >250 mg kg–1. On the average, elevated Pb concentration was evident in the soil samples from San Fernando, Olongapo, Malolos, Balanga, and Cabanatuan. The average soil Pb concentrations in these cities exceeded the maximum estimated natural soil Pb concentration of 25 mg kg–1. Average soil Pb concentration in Site 1 (16.8 mg kg–1) was well within the estimated natural concentration range of 5 to 25 mg kg–1. Data gathered from the study areas showed that elevated levels of Pb in soil were due primarily to vehicular emissions and partly to igneous activity. Recommendation and Outlook The findings of this study presented a preliminary survey on the extent of Pb contamination of soils in urban cities in central region of Philippines Island. With this kind of information on hand, government should develop a comprehensive environmental management strategy to address vehicular air pollution in urban areas, which shows as one of the most pressing environmental problems in the country. Basic to this is the continuous monitoring of Pb levels and other pollutants in air, soil, and water. Further studies should be conducted to monitor soil Pb levels in the six cities studied particularly in areas with elevated Pb concentration. The potential for harm from Pb exposure cannot be understated. Of particular concern are children who are more predisposed to Pb toxicity than adults. Phytoremediation of Pb-contaminated sites is strongly recommended to reduce Pb concentration in soil. Several studies have confirmed that plants are capable of absorbing extra Pb from soil and that some plants, grass species in particular, and can naturally absorb far more Pb than others.     

Neural Network Input Selection for Hydrological Forecasting Affected by Snowmelt1

Abstract: Snowmelt largely affects runoff in watersheds in Nordic countries. Neural networks (NN) are particularly attractive for streamflow forecasting whereas they rely at least on daily streamflow and precipitation observations. The selection of pertinent model inputs is a major concern in NNs implementation. This study investigates performance of auxiliary NN inputs that allow short‐term streamflow forecasting without resorting to a deterministic snowmelt routine. A case study is presented for the Rivière des Anglais watershed (700 km²) located in Southern Québec, Canada. Streamflow (Q), precipitations (rain R and snow S, or total P), temperature (T) and snow lying (A) observations, combined with climatic and snowmelt proxy data, including snowmelt flow (Q_SM) obtained from a deterministic model, were tested. NN implemented with antecedent Q and R produced the largest gains in performance. Introducing increments of A and T to the NNs further improved the performance. Long‐term averages, seasonal data, and Q_SM failed to improve the networks.