Climate change adaptation strategies for transportation infrastructure in Prince George,Canada

Transport infrastructure is particularly vulnerable to climate impacts as it is designed for long operational lives, and both episodic and seasonal conditions contribute to deterioration, disruption and unsafe incidents. There are some examples of adaptation in transportation design, but many communities do not have the capacity to incorporate climate change considerations into infrastructure planning and management. Researchers worked closely with the City of Prince George, in Central British Columbia, Canada, to build on existing work and explore how the City could plan, design, and maintain roads and other structures to account for climate change. A local steering committee was formed, and created and evaluated 23 potential research topics. Two focus areas were selected for further investigation and explored during a workshop with practitioners, researchers, consultants and other representatives. The workshop precipitated an investigation of projected impacts of climate change on road maintenance and road safety, and plans to explore alternative paving techniques. Outcomes of the case study provide insights regarding climate change and local transportation infrastructure, including: how researchers can engage with local experts to explore adaptation; issues local governments perceive as important; and barriers communities face as they attempt to address vulnerabilities.     

Near roadway concentrations of organic source markers

Concentrations of elemental carbon (EC), organic carbon (OC), and 33 organic source markers (12 alkanes, 18 polycyclic aromatic hydrocarbons and ketones, and 3 hopanes) are reported near a highway in Raleigh, NC with an annual average daily traffic count of approximately 125,000 vehicles. Daily samples (24-h) were collected at two locations, one approximately 10 m and the other 275 m perpendicular from the road. Concentrations of OC were similar between near (mean = 7.6 μg m^?3) and far (8.0 μg m^?3) locations, but concentrations of most organic species at the near site were between 1.5 and 2 times higher than those at the far site.     

Walking in the Irish countryside: landowner preferences and attitudes to improved public access provision

This paper explores the attitudes of landowners across Ireland to the wider provision of public access for recreational walking using a multinomial logit model. The study also investigates the level of compensation required to improve the supply of this public good. Results indicate that 51% of landowners are not willing to provide access (non-providers), 21% are willing to provide access free of charge (free providers) and 28% seek compensation (willing providers). The findings indicate that participation by landowners in a proposed public access scheme is influenced by landowners' experience with walkers, farm type, farm insurance costs, household demographics, regional variations, opportunity cost of land and participation in other agri-environment schemes. Mean willingness-to-accept for landowners willing to facilitate improved public access for walking was found to be €0.27 per metre of walkway.     

Toward an epistemology of public participation

This article uses an analysis of the 'knowledge politics' of the Botany Community Participation and Review Committee (CPRC) to argue that the Habermasian ideals framing the CPRC are flawed. Habermasian communicative ethics centre upon the notion that fair, free and open forms of debate and communication ensure that no one form of reasoning and/or knowledge dominates others, and so commonly frame attempts to facilitate public participation in technical decision-making. However, in practice, Habermas' advocacy of 'the power of the better argument' (1984) supports adversarial debate and favours conventionally validated (i.e. scientific) forms of knowledge over others. This article identifies this departure from the vision underpinning communicative ethics with the routine deployment of a flawed conception of knowledge. This view - that knowledge is representational in character (that is, in effect, a 'mirror' onto the world) - marginalises lay contributions by rendering them of secondary status (i.e. that they are 'values'); diminishes them by insisting that they take conventional 'expert like' representational form; and supports 'deficit model' approaches (the belief that public antipathy results from knowledge 'deficits' resolvable by expert mediated enhancements in technical literacy). A non-representational epistemology is used to argue that effective participation must rather account for how knowledge is constructed by and through processes, including those of participation/deliberation, rather than existing autonomously of them. The implications of this emphasis on processes, rather than on the sources of and formal characteristics of knowledge, are examined both for public participation and for the dynamics of late-modernity more generally.     

The contemporary cement cycle of the United States

A country-level stock and flow model for cement, an important construction material, was developed based on a material flow analysis framework. Using this model, the contemporary cement cycle of the United States was constructed by analyzing production, import, and export data for different stages of the cement cycle. The United States currently supplies approximately 80% of its cement consumption through domestic production and the rest is imported. The average annual net addition of in-use new cement stock over the period 2000–2004 was approximately 83 million metric tons and amounts to 2.3 tons per capita of concrete. Nonfuel carbon dioxide emissions (42 million metric tons per year) from the calcination phase of cement manufacture account for 62% of the total 68 million tons per year of cement production residues. The end-of-life cement discards are estimated to be 33 million metric tons per year, of which between 30% and 80% is recycled. A significant portion of the infrastructure in the United States is reaching the end of its useful life and will need to be replaced or rehabilitated; this could require far more cement than might be expected from economic forecasts of demand for cement.     

Responses of Physical, Chemical, and Biological Indicators of Water Quality to a Gradient of Agricultural Land Use in the Yakima River Basin, Washington

The condition of 25 stream sites in the Yakima River Basin, Washington, were assessed by the U.S. Geological Survey's National Water-Quality Assessment Program. Multimetric condition indices were developed and used to rank sites on the basis of physical, chemical, and biological characteristics. These indices showed that sites in the Cascades and Eastern Cascades ecoregions were largely unimpaired. In contrast, all but two sites in the Columbia Basin ecoregion were impaired, some severely. Agriculture (nutrients and pesticides) was the primary factor associated with impairment and all impaired sites were characterized by multiple indicators of impairment. All indices of biological condition (fish, invertebrates, and algae) declined as agricultural intensity increased. The response exhibited by invertebrates and algae suggested a threshold response with conditions declining precipitously at relatively low levels of agricultural intensity and little response at moderate to high levels of agricultural intensity. This pattern of response suggests that the success of mitigation will vary depending upon where on the response curve the mitigation is undertaken. Because the form of the community condition response is critical to effective water-quality management, the National Water-Quality Assessment Program is conducting studies to examine the response of biota to gradients of land-use intensity and the relevance of these responses to water-quality management. These land-use gradient pilot studies will be conducted in several urban areas starting in 1999.     

Use of n-fold cross-validation to evaluate three methods to calculate heavy truck annual average daily traffic and vehicle miles traveled

Reliable estimates of heavy-truck volumes in the United States are important in a number of transportation applications including pavement design and management, traffic safety, and traffic operations. Additionally, because heavy vehicles emit pollutants at much higher rates than passenger vehicles, reliable volume estimates are critical to computing accurate inventories of on-road emissions. Accurate baseline inventories are also necessary to forecast future scenarios. The research presented in this paper evaluated three different methods commonly used by transportation agencies to estimate annual average daily traffic (AADT), which is used to determine vehicle miles traveled (VMT). Traffic data from continuous count stations provided by the Iowa Department of Transportation were used to estimate AADT for single-unit and multiunit trucks for rural freeways and rural primary highways using the three methods. The first method developed general expansion factors, which apply to all vehicles. AADT, representing all vehicles, was estimated for short-term counts and was multiplied by statewide average truck volumes for the corresponding roadway type to obtain AADT for each truck category. The second method also developed general expansion factors and AADT estimates. Truck AADT for the second method was calculated by multiplying the general AADT by truck volumes from the short-term counts. The third method developed expansion factors specific to each truck group. AADT estimates for each truck group were estimated from short-term counts using corresponding expansion factors. Accuracy of the three methods was determined by comparing actual AADT from count station data to estimates from the three methods. Accuracy of the three methods was compared using n-fold cross-validation. Mean squared error of prediction was used to estimate the difference between estimated and actual AADT. Prediction error was lowest for the method that developed separate expansion factors for trucks. Implications for emissions estimation using the different methods are also discussed.     

Assessment of sediment contamination in Casco Bay, Maine, USA

The current status of contaminant concentrations in Casco Bay, decadal trends of these contaminants and changes in their geographical distribution are assessed using sediment samples collected approximately 10 years apart. In general, regulated contaminants appeared to be decreasing in concentration. Total PAH and dioxins/furans concentrations did not significantly change over this period. Total organochlorine pesticides, 4,4-DDE, 4,4-DDD, total DDT, PCB, tributyltin and total butyltin decreased in concentration. Trace element concentrations in sediments decreased at the majority of the sampling sites for chromium, nickel, and selenium while arsenic, cadmium, copper, lead, mercury, silver, and zinc remained relatively constant. None of the contaminants measured has increased by more than a factor of 2. Selected sites located in the Inner Bay, where concentrations are higher and new inputs were more likely, showed increased concentrations of contaminants. Most contaminants were not found at concentrations expected to adversely affect sediment biota based on ERL/ERM guidelines.     

Entry Deterrence and Signaling in a Nonrenewable Resource Model

We analyze a nonrenewable resource model in which an incumbent firm faces potential entry from a rival firm. The incumbent has private information about its stock size but the rival can observe extraction. With observable extraction and unobservable stock, the rival can use extraction as a signal about stock, from which it can infer whether entry is likely to be profitable. We characterize the necessary conditions for pooling and separating perfect Bayesian equilibria in a signaling game of resource extraction and provide examples of each. We show that the incumbent will often prefer pooling to separating even though welfare is higher in separating equilibrium.