Analysis of bus collision and non-collision incidents using transit ITS and other archived operations data

Introduction

This paper analyzes factors contributing to bus operations safety incidents at TriMet, the transit provider for the Portland Oregon metropolitan region.

Method

The analysis focuses on 4,631 collision and non-collision incidents that occurred between 2006 and 2009. Empirical analysis of these incidents draws on a wide array of operator-level data recovered by transit ITS technologies in combination with information from TriMet's human resources, scheduling, and customer relations databases. Incident frequencies are estimated in relation to operators' demographic characteristics, employment status, assigned work characteristics, service delivery and performance indicators, temporal factors, and customer information.

Results

Apart from identifying factors that are empirically related to the frequency of safety incidents, the findings offer insights into operations policies and practices that hold promise for improving safety.

Impact on Industry

Potential for safety improvement based on analysis of archived operations and human resource data.     

Getting to the core of core self‐evaluation: a review and recommendations

The theory of core self‐evaluation (CSE) has provided organizational scholars with a framework for describing disposition‐based effects on work attitudes and behaviors. Although the CSE construct has been useful for predicting various phenomena, there are potential weaknesses concerning how it is conceptualized and used. We review limitations regarding CSE theory, its measurement, and specific traits, and provide recommendations for addressing them. Key recommendations include strengthening the theory underlying CSE, specifying CSE as an aggregate construct with causal indicators, representing CSE as a multidimensional construct rather than a scale score, and incorporating a trait that reflects approach motivation. Theoretical and empirical evidence that relate to our recommendations are presented. Copyright © 2007 John Wiley & Sons, Ltd.     

Forcing the Pace of Biodiversity Action: a force-field analysis of conservation effort at the 'landscape scale'

Biodiversity planners increasingly recognise the need for delivering action on a 'wider countryside', rather than on a purely site-centred, basis. Ecological processes often take place at the 'landscape scale' and are not sufficiently accommodated within reserves, and a failure to reflect this in biodiversity planning has been one of the contributors to species and habitat decline. However, there are generally few powers to enforce compliance with spatial rural land-use strategies, and biodiversity plans at the landscape scale must rely heavily on incentives, advice and goodwill. Not surprisingly, this results in a substantial gap between policy and implementation. One way of analysing the causes of, and potential solutions to, implementation failure is to examine the barriers to plan uptake. This paper addresses barriers to biodiversity action in three case-study areas in terms of 'force fields', depicting the nature and strength of negative and positive influences on land managers and conservation staff. It is concluded that a clearer understanding of the nature of 'barriers' can lead to improved targeting on potential 'bridges' to a better future.     

DEVELOPMENT OF AN INVERTEBRATE COMMUNITY INDEX FOR AN ALABAMA COASTAL PLAIN WATERSHED1

ABSTRACT: Activities such as agriculture, silviculture, and mining contribute nonpoint pollution to Alabama's streams through polluted runoff and excessive sedimentation. Highly erodible soils characteristic of the Choctawhatchee‐Pea Rivers watershed, combined with intense rainfall and land use practices, contribute large amounts of sediment to streams. Biological monitoring can reflect the acute impacts of pollutants as well as prolonged effects of habitat alteration, and development of biological criteria is important for the establishment of enforceable laws regarding nonpoint source pollution. Macroinvertebrates were collected from 49 randomly selected sites from first through sixth‐order streams in the Choctawhatchee‐Pea Rivers watershed and were identified to genus level. Thirty‐eight candidate metrics were examined, and an invertebrate community index (ICI) was calibrated by eliminating metrics that failed to separate impaired from unimpaired streams. Each site was scored with those metrics, and narrative scores were assigned based on ICI scores. Least impacted sites scored significantly lower than sites impacted by row crop agriculture, cattle, and urban land uses. Conditions in the watershed suggest that the entire area has experienced degradation through past and current land use practices. An initial validation of the index was performed and is described. Additional evaluations of the index are in progress.     

Time discounting and the decision to protect areas that are near and threatened or remote and cheap to acquire

Should conservation organizations focus on protecting habitats that are at imminent risk of being converted but are expensive or more remote areas that are less immediately threatened but where a large amount of land can be set aside? Variants of this trade‐off commonly arise in spatial planning. I used models of land‐use change near a deforestation frontier to examine this trade‐off. The optimal choice of where to protect was determined by how decisions taken today accounted for ecological benefits and economic costs of conservation actions that would occur sometime in the future. I used an ecological and economic discount rate to weight these benefits and costs. A large economic discount rate favored protecting more remote areas, whereas a large, positive ecological discount rate favored protecting habitat near the current deforestation frontier. The decision over where to protect was also affected by the influence economic factors had on landowners' decisions, the rate of technological change, and ecological heterogeneity of the landscape. How benefits and costs through time are accounted for warrants careful consideration when specifying conservation objectives. It may provide a niche axis along which conservation organizations differentiate themselves when competing for donor funding or other support.     

Sectoral sustainability and sustainability assessment methodologies: A review of methodology in light of collaboration with the UK oil and gas sector

This paper discusses methodologies that have been employed to give insights into business performance in relation to sustainable development, both at a sectoral and corporate level. From consideration of different sectoral sustainable development methodologies, some key issues and good practice related to their derivation are elaborated. These issues are then further illustrated by a detailed comparison between three sustainable development methodologies that have been used in the UK offshore oil and gas industry. The methodologies chiefly differ in terms of how they address the problem of comparing different impacts across potentially non-commensurable dimensions, one proceeding through explicit monetary valuation, another through implicit valuation of different options and another through presentation of an unaggregated framework of indicators. The paper concludes by identifying the different situations in which use of these different methodologies is appropriate.     

Effects of Riparian Areas,Stream Order,and Land Use Disturbance on Watershed‐Scale Habitat Potential: An Ecohydrologic Approach to Policy1

Abstract: Spatio‐temporal linkages between hydrologic and ecologic dimensions of watersheds play a critical role in conservation policies. Habitat potential is influenced by variation along longitudinal and lateral gradients and land use disturbance. An assessment of these influences provides critical information for protecting watershed ecosystems and in making spatially explicit, conservation decisions. We use an ecohydrologic approach that focuses on interface between hydrological and ecological processes. This study focuses on changes in watershed habitat potentials along lateral (riparian), and longitudinal (stream order) dimensions and disturbance (land use). The habitat potentials were evaluated for amphibians, reptiles, mammals, and birds in the Westfield River Watershed of Massachusetts using geographic information systems and multivariate analysis. We use a polynomial model to study nonlinear effects using robust regression. Various spatial policies were modeled and evaluated for influence on species diversity. All habitat potentials showed a strong influence along spatial dimensions and disturbance. The habitat potential for all vertebrate groups studied decreased as the distance from the riparian zone increased. Headwaters and lower order subwatersheds had higher levels of species diversity compared to higher order subwatersheds. It was observed that locations with the least disturbance also had higher habitat potential. The study identifies three policy criteria that could be used to identify critical areas within a watershed to conserve habitat suitable for various species through management and restoration activities. A spatially variable policy that is based on stream order, riparian distance, and land use can be used to maximize watershed ecological benefits. Wider riparian zones with variable widths, protection of headwaters and lower order subwatersheds, and minimizing disturbance in riparian and headwater areas can be used in watershed policy. These management objectives could be achieved using targeted economic incentives, best management practices, zoning laws, and educational programs using a watershed perspective.