Why are work travel plans effective? Comparing conclusions from narrative and meta-analytical research synthesis

Reliable research synthesis is of high significance for a transport policy which tries to base its decisions on available empirical evidence. There is growing doubt whether the frequently used narrative approach provides a scientifically defensible way of synthesising a body of quantitative research results. The present paper demonstrates meta-analysis as a more objective and powerful alternative for this task. For this purpose evaluation data synthesised in two earlier narrative reviews on the effectiveness of work travel plans [Cairns et al. Making travel plans work: research report (former), Department for Transport, Local Government and the Regions (DTLR), London, 2002; Smarter choices—changing the way we travel. (Final report of the research project: The influence of soft factor interventions on travel demand. Research report for the Department for Transport.) London. Retrieved 1 December 2005, from , 2004] are meta-analytically re-analysed and compared with the conclusions drawn from the narrative synthesis of these data. Our meta-analyis provides only limited support for the conclusion that addressing parking is the hallmark of successful work travel plans. Our meta-analysis indicates that site and organisational factors as well as characteristics of the monitoring process are significant predictors of effective work travel plans, whereas Cairns et al. view little evidence for the impact of these factors.     

Influences on bicycle use

A stated preference experiment was performed in Edmonton in Canada to both examine the nature of various influences on bicycle use and obtain ratios among parameter values to be used in the development of a larger simulation of household travel behaviour. A total of 1128 questionnaires were completed and returned by current cyclists. Each questionnaire presented a pair of possible bicycle use alternatives and asked which was preferred for travel to a hypothetical all-day meeting or gathering (business or social). Alternatives were described by specifying the amounts of time spent on three different types of cycling facility and whether or not showers and/or secure bicycle parking were available at the destination. Indications of socio-economic character and levels of experience and comfort regarding cycling were also collected. The observations thus obtained were used to estimate the parameter values for a range of different utility functions in logit models representing this choice behaviour. The results indicate, among other things, that time spent cycling in mixed traffic is more onerous than time spent cycling on bike lanes or bike paths; that secure parking is more important than showers at the destination; and that cycling times on roadways tend to become less onerous as level of experience increases. Some of these results are novel and others are consistent with findings regarding bicycle use in work done by others, which is seen to add credence to this work. A review of previous findings concerning influences on cycling behaviour is also included.     

台湾海底隧道之接头与管段变化研析及对策

台湾唯一之海底隧道系采沉埋方式施工,该隧道不仅处于具高度盐份腐蚀之不利环境,且位于软弱地盘上.于营运二十余年后,轻微异状已有显现,如管段接头锈蚀、管体渗漏及管体裂损等异状.上述异状可能为接头构件变形、管体变位/变形及结构劣化等影响隧道安全之前兆,甚至降低其耐震能力;因该隧道肩负港区及区域经济发展之运输重任,如何藉由整体性体检进行安全评估及研订适当之维护补强对策,为计划执行重点;故本文将说明隧道接头、结构体等隧道重要构件之检测调查(如地球物理、钢筋腐蚀、裂缝深度、氯离子试验、防蚀电位、接头防水等项目)、数值分析及自动化监测(接缝计、单元沉陷仪、结构倾斜仪、电位计等)等综合评估结果及维护补强对策,以提供工程界日后参考.     

Numerical modelling of fish eggs dispersion at the Patos Lagoon estuary — Brazil

The Patos Lagoon estuary is the most important nursery ground for commercially relevant species of fish and crustaceans in the South of Brazil, maintaining fisheries that sustain 3500 fisher families throughout the Rio Grande do Sul State coastline. Around 80% of the interior estuarine area is very shallow (< 2 m), and recruitment of fish eggs and larvae to the inner parts of the Patos Lagoon estuary is directly related to the circulation pattern in the area, which is controlled by local and non-local wind effects and freshwater discharge. The objective of this study is to investigate the processes controlling the transport of estuarine dependent fish eggs between the Atlantic Ocean and the Patos Lagoon estuary.An integrated numerical system based on a bi-dimensional hydrodynamic model and a Lagrangean transport model of passive particles is applied to a selection of scenarios representing the passage of weather fronts over the area. At this stage, fish eggs are represented as buoyant passive particles. Modelling results are compared against field data for the period under investigation (September/October 1999) and historical records. Short term results are analysed in terms of the meteorological conditions (wind direction, intensity and duration) controlling the transport of eggs to the inner parts of the estuary and the extension of their excursion. This experiment is the first attempt to couple biological and physical information to study fish eggs transport, and to enhance the current knowledge about recruitment of important fisheries resources in southern Brazil.     

An algorithm for solving asymmetric equilibrium problems with a continuous cost-flow function

The paper gives two user objective functions for the asymmetric assignment problem, and an algorithm of descent type. The algorithm produces a sequence of flows which converges to the set of equilibria if the cost-flow function is continuous.     

Evaluation of truck configurations based on structural performance of bridges

Contained herein are the results of research which quantifies the effects that various existing and projected truck configurations have as live loadings upon bridges which currently exist on the National Bridge Inventory (NBI). The truck configurations were determined from those actual or proposed vehicles which exhibit the highest GVW and which either are causing or are perceived to cause the highest levels of overstress on bridge superstructure elements. In order to simulate most accurately the actual field conditions, a criterion was defined which contained three major requirements: 1) The bridges utilized within the study shall be defined as being a statistically significant sample and be actual bridges taken from the NBI; 2) The analysis method shall be consistent with those actually used by engineers in designing and rating bridges, and; 3) The criteria utilized in evaluating the various bridge structures under the defined loadings shall be consistent with current practices. The results obtained indicates the acceptability of various truck configurations by GVW, size, and axle deployments, by system for the different criteria now in use.     

Car drivers' willingness to pay for not losing their driving licence

The aim of this article is to discuss theoretically and to study empirically how Norwegian drivers' willingness to pay (WP) for not losing their driving licence vary with their personal characteristics. The theoretical discussion and empirical results are based on standard microeconomic theory and contingent valuation, respectively. The WP values increase concavely with the length of the suspension period of the driving licence and differ greatly between drivers. They increase significantly with a driver's income, dependence on the car at work and driving experience. Moreover, male drivers, young drivers and drivers living in rural areas have higher WP values than their counterparts. Consequently, driving licence suspension will deter drivers to different extents. The relative impacts of the above explanatory variables on the WPs are, broadly speaking, independent of the length of the suspension period.     

Phenetic relationships among some free-living siphonostomatoid copepods from southwest Ireland, and the description of Glannapontius maculatus gen. et sp. nov.

Glannapontius maculatus gen. et sp. nov. is described from southwest Ireland. It is a typical example of a free-living siphonostomatoid copepod, and exhibits some intermediate features between the Asterocheridae and Artotrogidae. It is here placed in the Artotrogidae, based on an assessment of 120 morphological dichotomous characters measured on 11 species, and grouped using Average Linkage Cluster Analysis.     

Application of a validated primary production model (BLOOM) as a screening tool for marine, coastal and transitional waters

In order to manage aquatic systems, it is necessary to apply methods relating the environmental variables and system-state parameters with external factors that affect the system. External factors can be natural (i.e. the movement of water) or partly-anthropogenic (i.e. nutrient loads). In addition to the national authorities, who have been implementing environmental policies for several decades, the EU is presently implementing the Water Framework Directive (WFD) aimed at establishing a new set of standards for the ecological and water quality of water systems. Among these are the phytoplankton biomass and composition. Phytoplankton affects turbidity, oxygen depletion, total productivity of the system and the occurrence of (harmful) algal blooms. A range of methods is available to relate phytoplankton to the controlling environmental conditions. Among these are statistical relations for instance of the Vollenweider type as well as deterministic simulation models. At the end of the 1970s, a generic deterministic phytoplankton module called BLOOM was developed, which has since been applied to a wide range of fresh water and marine systems. Here we test the applicability of this model as a screening tool for coastal waters. We conclude that the model is able to reproduce observed chlorophyll levels adequately under a wide range of conditions. Subsequently the model is applied to demonstrate the potential impacts of reductions in nitrogen, phosphorus or both nutrients simultaneously. Depending on which factors are initially controlling, the impacts of these reductions vary considerably both between locations and during the season. While this type of application lacks explicit relations between nutrient concentrations and external loadings, it does consider a number of relevant conditions in a consistent way and requires remarkably little data and effort. It is therefore a valuable screening tool.