Substantial Changes and Their Impact on Mobility: A Typology and an Overview of the Literature

During the past 40 years, mobility patterns have enduringly changed several times as a result of the occurrence of a number “substantial changes”. Examples of such substantial changes are the rapid emergence of affordable air travel, the oil crises, and profound ICT developments. To most researchers and policy-makers in transportation, it seems more than likely that the next 40 years will also witness a number of substantial changes, some of which might even have larger impacts on mobility than the ones described above. However, literature on substantial changes and their impact on mobility are difficult to access as it is spread across different research fields and suffers from ambiguous use of terminology. As a result, overview of the literature on substantial changes and their findings is missing and discussions on the impacts on future mobility of potential substantial changes are hampered. To overcome these problems, this paper (1) proposes a typology of substantial changes and (2) ties together and reviews the scholarly literature that has focused on identifying the impacts of past substantial changes on mobility patterns. In this paper, we show how the proposed typology on substantial changes can be applied to contemplate on substantial changes and on their impacts.     

Combining Intermodal Transport With Electric Vehicles: Towards More Sustainable Solutions

Abstract

This paper analyses the feasibility of incorporating electric or hybrid vehicles in intermodal transport for the transportation of containers in the pre- and post haulage (PPH) operation. In Europe, the intermodal transport market is being strongly supported, as it is seen as one of the keystones of a sustainable mobility system policy. The introduction of environmentally friendly electric/hybrid vehicles for the pre- and post haulage operation would mean a further enhancement leading to a more complete ecological intermodal transport chain. PPH operations are usually no longer than 30 km, and, hence, could possibly be handled by electric or hybrid vehicles.

Hybrid electric vehicles (HEV) combine electric and other drive systems, such as internal combustion engines, gas turbines and fuel cells. Hybrid electric vehicles merge the zero pollution and high efficiency benefits of electric traction with the high fuel energy density benefits of an energy source or thermal engine. The use of electrically driven vehicles for goods distribution has already been successfully proven in international demonstration projects, such as ELCIDIS. Transport of intermodal units (such as ISO containers), however, requires electric/hybrid heavy-duty goods vehicles, which are not readily available on the market, but for which the technology exists.

Different possibilities are assessed as to their technical, financial, organizational and environmental feasibility and suitability. This analysis is based on a typical mission for pre-and post haulage operations, such as type of trips, distance, frequency, urban/suburban, etc.     

Expansion of a Controlled Parking Zone (CPZ) and its Influence on Modal Split: The Case of Edinburgh

Abstract

This article considers the inter-relationship between on-street parking and choice of mode for journeys to work in the Scottish city of Edinburgh. This city is typical of many in that its centre has significant on-street parking controls but, beyond a radius of 1 to 1 1/2 miles (1.5 to 2.5?km) from the centre, there are no controls and commuter parking on-street is commonplace. The article reviews the relevant literature, and then considers the results of a survey undertaken of Edinburgh city centre employees in order to ascertain their parking habits and likely response to the extension of existing on-street parking controls. The article concludes that the results are transferable to other cities but that the scale of the impacts in each will be related to site specific factors, particularly the demand for residential parking space on-street in areas close to the city centre.     

Commuting trips within tours: how is commuting related to land use?

Studies that model the effects of land use on commuting generally use a trip-based approach or a more aggregated individual-based approach: i.e. commuting is conceptualized in terms of modal choice, distance and time per single trip, or in terms of daily commuting distance or time. However, people try to schedule activities in a daily pattern and, thus, consider tours instead of trips. Data from the 2000 to 2001 Travel Behaviour Survey in Ghent (Belgium) illustrate that car use and commuting times significantly differ between commuting trips within work-only tours and more complex tours. Therefore, this paper considers trip-related decisions simultaneously with tour-related decisions. A multiple group structural equation model (SEM) confirmed that the relationship between land use and commuting differs between work-only tours and more complex tours. Trips should be considered within tours in order to correctly understand the effect of land use scenarios such as densifying on commuting. Moreover, the use of multiple group SEM enabled us to address the issue of the complex nature of commuting. Due to interactions between various explanatory variables, land use patterns do not always have the presumed effect on commuting. Land use policy can successfully influence commuting, but only if it simultaneously accounts for the effects on car availability, car use, commuting distance and commuting time.     

Benzene concentrations on board chemical tankers

Maritime transport of benzene is regulated by the International Maritime Organisation (IMO). Two important guidelines for a ship’s crew in this matter are IMO circulars 1095 and 1220. The first one describes the minimum safety standards for ships carrying liquids in bulk containing benzene while circular 1220 deals with structural guidelines for new ships carrying liquids in bulk containing benzene, but also technical developments could help in improving safety and health protection on board chemical tankers carrying benzene in bulk. The aim of the present paper is to determine the benzene concentration in the working and living environment on board a modern chemical tanker carrying benzene in bulk, where all safety, technical and operational procedures described by IMO in the above-mentioned circulars are followed. During specific cargo operations, we measured the benzene concentrations on different locations on board by means of Radiello® passive diffusive samplers. Despite all measures taken, we found an important difference in benzene concentration between operations with a benzene cargo compared to operations without benzene on board, as well as inside and outside the accommodation. Moreover, even during discharge operations, where the emission is theoretically zero, we found an important increase in the benzene concentration. In addition, we found less favourable results for the engine room.     

Perceived Diving Impacts and Management Implications at a Popular South African Reef

Coral reefs are threatened by impacts such as from scuba diving, and ongoing research is required to assess diving impacts, diver behavior and environmental knowledge. This study investigated perceived diving impacts, reef condition and norms among scuba divers at Sodwana Bay (South Africa). Divers viewed contact with coral as damaging, and perceived environmental degradation at dive sites. However, most divers saw activities such as photography as causing little or no damage to reefs. One meter or less was believed to be a safe distance from the reef or the wildlife to avoid contact or disturbance, and encounter norms were high. Age and experience influenced most perceptions, although cannot be accepted as reliable indicators of divers' perceptions or behavior, due to the heterogeneous conduct of divers of various experience and age as described in literature. The importance of human perceptions to understand what strategies need implementation in diving management is discussed.     

燃油泵的诊断

更换现代燃油喷射汽车的电动燃油泵,并非一件非常简单的事情。本文将提供有关电动燃油泵诊断的基础知识,以便在你怀疑燃油泵存在问题时,帮你提高诊断成功的机会。     

Heterogeneous traffic flow modelling for an arterial using grid based approach

A grid based modelling approach akin to cellular automata (CA) is adopted for heterogeneous traffic flow simulation. The road space is divided into a grid of equally sized cells. Moreover, each vehicle type occupies one or more cell as per its size unlike CA traffic flow model where each vehicle is represented by a single cell. Model needs inputs such as vehicle size, its maximum speed, acceleration, deceleration, probability constants, and arrival pattern. The position and speed of the vehicles are assumed to be discrete. The speed of each vehicle changes according to its interactions with other vehicles, following some stochastic rules depending on the circumstances. The model is calibrated and validated using real data and VISSIM. The results indicate that grid based model can reasonably well simulate complex heterogeneous traffic as well as offers higher computational efficiency needed for real time application.     

多约束分离路径算法

多媒体流和视讯会议等新应用的出现要求网络提供可靠的服务质量(QoS)保证。为网络中的每对节点建立两条多约束链路/节点分离路由是提供可靠QoS的一条重要途径。如何建立两条链路/节点分离多约束路径是一个关键问题,这一问题与经典的一维测度下的分离路径问题有着很多概念上的不同。本文分析了这一问题的困难性,并提出一组解决此问题的启发式算法。     

Could you also have made this trip by another mode? An investigation of perceived travel possibilities of car and train travellers on the main travel corridors to the city of Amsterdam,The Netherlands

We investigated perceived travel possibilities (or subjective choice-sets, consideration-sets) of car and train travellers on the main corridors to the city of Amsterdam, The Netherlands, and associations with traveller and trip characteristics. We conducted secondary analysis on a survey sample consisting of 7950 train and 19,232 car travellers. Forty-five percent of train travellers had a car in their objective choice-set, 27% of them would however never use it for this trip. Trip destination city centre, trip purpose, paying for the trip, public transport commitment, traffic congestion and parking problems were associated with consideration of car as alternative. Forty-two percent of car travellers had public transport in their subjective choice-set. The ratio between perceived public transport and objective car travel time stood out as determinant of consideration-sets, next to destination city centre, trip purpose, travel time and private versus company car ownership. On average, car travellers’ perceptions of public transport travel time exceeded objective values by 46%. We estimated that if perceptions would be more accurate, two out of three car travellers that currently do not see public transport as an alternative would include it in their choice-set, and use it from time to time. This effect has strong theoretical and policy implications.