The socio-cognitive links between road pricing acceptability and changes in travel-behavior

The objective of this study is to examine the effect of road pricing on people’s tendency to adapt their current travel behavior. To this end, the relationship between changes in activity-travel behavior on the one hand and public acceptability and its most important determinants on the other are investigated by means of a stated adaptation experiment. Using a two-stage hierarchical model, it was found that behavioral changes themselves are not dependent on the perceived acceptability of road pricing itself, and that only a small amount of the variability in the behavioral changes were explained by socio-cognitive factors. The lesson for policy makers is that road pricing charges must surpass a minimum threshold in order to entice changes in activity-travel behavior and that the benefits of road pricing should be clearly communicated, taking into account the needs and abilities of different types of travelers. Secondly, earlier findings concerning the acceptability of push measures were validated, supporting transferability of results. In line with other studies, effectiveness, fairness and personal norm all had a significant direct impact on perceived acceptability. Finally, the relevance of using latent factors rather than aggregate indicators was underlined.     

HMB Reflectors: A New Horizontal Retro‐reflecting System to Improve Safety at Pedestrian Crossings

Abstract

Each year more than 1000 pedestrians are injured in accidents on pedestrian crossings in Switzerland. The accidents often occur in darkness, twilight or poor visibility during rain at locations without sufficient public street lighting because vehicle drivers notice the pedestrian crossing too late or overlook it altogether. Pedestrian crossings can be made significantly easier for vehicle drivers to recognize at night and in poor visibility by means of HMB reflectors. When crossing sites are made more conspicuous with high horizontal retro‐reflecting markers, the readiness to stop increases. The reflectors can thus contribute to improving road safety at pedestrian crossings. This new low‐cost measure has a wide range of applications. The new reflector system is currently gaining ground in Switzerland and several other European countries.     

The identification of factors influencing destination choice: An application of the repertory grid methodology

A common problem of all cognitive-behavioural models of destination choice is that of the identification of factors influencing the behaviour of interest. This paper considers the applicability of Kelly's repertory grid methodology to identify the factors influencing consumer choice of shopping centres. Firstly, some methodological issues in the assessment of the relative importance people attach to certain variables in deciding where to shop are discussed. Secondly, the main findings of an application of the repertory grid methodology are presented. The paper concludes by discussing some implications of the measurement of the determinants of choice behaviour and the construction of mathematical models of destination choice.     

Optimal Control Model Applications and Field Measurements with Respect to Car Driving

The well-known optimal control model has been applied only rarely to car driving, although its structure suits the modelling demands of driving by allowing for a multitask application and providing possibilities for the evaluation of driving in terms of supervisory control. Two series of Supervisory Driver Model predictions are stated for lateral position control in a straight driving scenario with disturbances generated internally by the driver. The first series of model calculations predicts lateral position variations and the time that a driver's vision can be occluded during the observation and control of different combinations of display variables (lateral position, lateral speed, yaw rate, lateral acceleration and yaw acceleration). The second series of predictions concerns two extreme sets of display variables in relation to driving speed and driving experience. Model predictions for the observation and control of all display variables give occlusion times which correspond with data from instrumented car studies with experienced drivers. However, with exclusive observation and control of the lateral position cue, predicted occlusion times are less than found in experimental results of inexperienced drivers. It is suggested that inexperienced drivers are also controlling yaw rate and/or both acceleration cues.     

Measuring inefficiency in the Norwegian bus industry using multi-directional efficiency analysis

This paper deals with methods of measuring and analyzing efficiency in the transport industry. The aim of the paper is to introduce and demonstrate the advantages of Multi-directional Efficiency Analysis (MEA) in the case of cost data with limited substitution possibilities. For this purpose we reconsider the Norwegian bus data that has previously been analyzed using econometric models and Data Envelopment Analysis; Jørgensenet al. (1995, 1997) and Odeck and Alkadi (2001). It is shown how, using MEA, it becomes possible to disaggregate inefficiency into different components corresponding to different types of cost generating variables and thereby providing both managers of the bus companies and policy makers with more detailed information on possible improvements in performance.     

On the Theory of Nonlinear Dynamics and its Applications in Vehicle Systems Dynamics

We present a brief outline of nonlinear dynamics and its applications to vehicle systems dynamics problems. The concept of a phase space is introduced in order to illustrate the dynamics of nonlinear systems in a way that is easy to perceive. Various equilibrium states are defined, and the important case of multiple equilibrium states and their dependence on a parameter is discussed. It is argued that the analysis of nonlinear dynamic problems always should start with an analysis of the equilibrium states of the full nonlinear problem whereby great care must be taken in the choice of the numerical solvers. When the equilibrium states are known certain linearizations around one chosen state may be applied carefully in order to facilitate or speed up the numerical solution of the dynamical problem. It is argued, however, that certain problems cannot be linearized. The applications of nonlinear dynamics in vehicle simulations is discussed, and it is argued that it is necessary to know the equilibrium states of the full nonlinear system before the simulation calculations are performed.     

The Influence of In-Plane Tyre Dynamics on ABS Braking of a Quarter Vehicle Model

For efficient analysis it is important to choose the proper model that fits the problem that needs to be solved. This paper discusses three pragmatic simulation models for longitudinal behaviour of a passenger car tyre (Steady State, Transient and Rigid Ring) that may be used in e.g. an ABS simulation. The characteristics of the simulation models are evaluated using some simple simulations. Simulations with a quarter vehicle model that includes load transfer effects are carried out to determine the deviation in results between the mentioned tyre models for an ABS application. The results show that the Steady State model may only be used below 10 Hz and that the Transient model is valid up to about 30 Hz. The results from the ABS simulation with the Rigid Ring model are most reliable and are clearly different from the Steady State and Transient model, which indicates that ABS simulations should be carried out with the Rigid Ring model. Additionally it is demonstrated that for tyre behaviour on uneven roads the influence of the tyre belt cannot be neglected.     

腹主动脉瘤患者血浆MMP-9含量测定及其意义

目的　初步探讨基质金属蛋白酶 9(MMP 9)在腹主动脉瘤 (AAAs)致病机制中的作用。方法　采集 2 0 0 2年 2月至2 0 0 2年 8月德国科隆大学医院血管外科中心收治的 35例AAAs患者治疗前后的血液标本 ,利用酶联免疫分析方法(ELISA)逐一测定血浆MMP 9含量 ,并检测同期住院的 10例动脉硬化闭塞性疾病 (AODs)患者的血浆MMP 9含量作为对照。结果　AAAs患者术前血浆MMP 9含量明显高于AODs患者 [(90 .2 5± 9.12 ) μg·L-1vs.(2 3.5 8± 7.33) μg·L-1,P <0 .0 5 ],治疗后 1月血浆MMP 9含量明显下降 ,与术前相比有显著差异 [(2 8.5 5± 8.35 ) μg·L-1vs.(90 .2 5± 9.12 ) μg·L-1,P <0 .0 5 ],而与AODs患者无显著差别 [(2 8.5 5± 8.35 ) μg·L-1vs.(2 3.5 8± 7.33) μg·L-1,P >0 .0 5 ]。AODs患者治疗前后的MMP 9血浆水平无明显变化 [(2 3.5 8± 7.33) μg·L-1vs.(2 5 .2 8± 5 .78) μg·L-1,P >0 .0 5 ]。结论　腹主动脉瘤患者血浆MMP 9水平的明显升高 ,提示MMP 9与腹主动脉瘤的发病有密切关系 ;动态监测MMP 9含量变化有望成为腹主动脉瘤的早期诊断及术后疗效判断的重要手段。     

A test of the two-mode UMOT in the Netherlands

The UMOT model, presented as an alternative to conventional travel demand models, is critically examined for its feasibility to predict vehicle distance travelled and average daily traffic in The Netherlands. Using data from the National Travel Survey (OVG) 1978 a Dutch version of UMOT is developed, and an attempt is made to validate it on historical data from the period 1960 to 1980. Some comparisons are made with results of similar work using 1976 survey data in the UK by the Transport and Road Research Laboratory.