“Not just a taxi”? For-profit ridesharing,driver strategies,and VMT

The spread of GPS-based location services using smartphone applications has led to the rapid growth of new startups offering smartphone-enabled dispatch service for taxicabs, limousines, and ridesharing vehicles. This change in communicative technology has been accompanied by the creation of new categories of car service, particularly as drivers of limousines and private vehicles use the apps to provide on-demand service of a kind previously reserved for taxicabs. One of the most controversial new models of car service is for-profit ridesharing, which combines the for-profit model of taxi service with the overall traffic reduction goals of ridesharing. A preliminary attempt is here made at understanding how for-profit ridesharing compares to traditional taxicab and ridesharing models. Ethnographic interviews are drawn on to illustrate the range of motivations and strategies used by for-profit ridesharing drivers in San Francisco, California as they make use of the service. A range of driver strategies is identified, ranging from incidental, to part-time, to full-time driving. This makes possible a provisional account of the potential ecological impacts of the spread of this model of car service, based on the concept of taxicab efficiency, conceived as the ratio of shared versus unshared miles driven.     

An overview of transport in Kuwait

Abstract

Kuwait is a relatively small country located at the top of the Arabian Gulf with population in 1980 amounting to 1.355 millions. Kuwait occupies an area of approximately 17 800 square kilometres. Kuwait's main source of national income is oil export. Income from oil export and other sources has resulted in Kuwait having the highest per capita income in the world. Consequently vehicle ownership is very high and traffic is ever growing and extending. Kuwait is self‐sufficient in only a few commodities and has a shortage of local labour. This means that transport has a fundamental role to play at the national and international level for the development of Kuwait's economy.

This paper provides a brief statement of transport in Kuwait. It starts by describing Kuwait's national setting and touches on the economic and social aspects in Kuwait that have an influence on transport patterns and needs. It describes the national transport system and covers road, air, rail and ports. Urban development planning in Kuwait is described and issues related to stages of urban development planning. The Kuwait City Master Plan and new town initiatives are presented. The urban transport system in Kuwait Metropolitan Area is described. In particular the characteristics of the urban road network and public transport facilities are outlined along with recent transport planning studies and new initiatives in the urban transport system.

The paper ends with a statement on organizations involved in the transport sector in Kuwait and a note on transport finance.     

Optimization of transport investment and pricing policies: the role of transport pricing in network design

This paper investigates the role of transport pricing in network design and describes two facts about flow pattern in a transportation system. The first, illustrated by an example of Braess paradox, is that adding a new link to the network does not necessarily minimize the total travel time. The second is that introducing of appropriate toll pricing may reduce not only the total network time but also the travel time for each individual traveller. It follows with the investigations of different system objectives and different pricing policies (only toll pricing and distance‐based pricing are considered), and shows how they affect the system performance and flow pattern. Lastly, a systematic optimization process is proposed for integrated planning of transport network and pricing policies.     

Ocean Citizenship: An Emergent Geographical Concept

Ocean citizenship describes a relationship between our everyday lives and the health of the coastal and marine environment. Through our everyday lives we affect, and are affected by, the marine and coastal environment in numerous ways. As such, individuals have a responsibility to make informed lifestyle choices to minimize this impact. In doing so, the actions of individuals can contribute to the amelioration of large-scale and seemingly insurmountable geographical problems. This article outlines the concept of ocean citizenship within the context of the public understanding of marine environmental issues. The article draws heavily on the experience of the National Maritime Museum as an important contributor to the development of ocean citizenship in the United Kingdom. Specifically, the Planet Ocean initiative will be examined, in which the Museum has adopted a multimodal approach to public engagement through exhibitions, educational resources, and specific research publications. The article concludes by highlighting the importance of geography in the development and sustainability of ocean citizenship.     

Initiatives in Philippine Coastal Management: An Overview

Standardized and free-format questionnaires on the state of coastal management were fielded to coastal management practitioners during three workshops and a national feedback and recommendation workshop. The most commonly cited responses were identified for each of 13 political regions and overall trends were identified. Management frameworks frequently included research, community organizing, education, livelihood, resource enhancement, resource protection, regulation, and networking components. Gender issues, documentation, and infrastructure investment were rare. The most commonly perceived environmental problem was illegal/ destructive fishing and its associated overfishing and low fish catch. The most commonly cited socioeconomic problem was the inadequacy of law enforcement. The best monitored variables were usually those related to environmental management: status and change of habitats, resources, and degree of enforcement/patrolling activities. The most common nonregulatory enhancement, aside from environmental education (which is the most popular), was mangrove reforestation. In terms of regulations, the majority of the respondents have reportedly formulated an integrated coastal management plan. In practice, regulating destructive and illegal fishing practices and then the establishment of fish sanctuaries are the next most implemented. The most popular quality-of-life enhancement strategies focused on the improvement of sustainable fishing as a livelihood and on a variety of supplementary livelihoods. The most usual institutional intervention being implemented was the setting up of local community people's organizations. Major factors which may influence success or failure of coastal management and recommendations on research, community organizing and livelihood, legislation and policies, implementation and coordination, and networking are also summarized.     

Commentaries

Abstract

This paper surveys the technologies available for constructing a pervasive, national‐scale road pricing system. It defines the different types of road pricing, the methods by which a vehicle’s position can be determined, and then examines possible pricing regimes in the context of their technological requirements and implications. The issue of enforcement and the distribution of pricing policies are considered, and further complexities are outlined. An examination of the security aspects of such systems is made, focusing particularly on the need to ensure privacy using technological, rather than solely procedural, methods. The survey concludes that a pervasive, national‐scale deployment is unlikely to be technically achievable in the short‐term.     

In situ colonization of marine biofilms on UNS S32760 duplex stainless steel coupons in areas with different water qualities: Implications for corrosion potential behavior

In the presence of biofilms, stainless steels （SS） exhibits an increase in corrosion potential, called ennoblement. In the present study, the corrosion potential （Eco,） behavior of the duplex SS UNS S32760 was recorded simultaneously with the in situ marine biofilm formation in two areas at Arraial do Cabo, Southeastern Brazil. The biofilm at Forno Harbor （an anthropogenically disturbed area） was characterized by higher relative abundances of Bacteria at day 2, followed by diatoms （especially Navicula sp.） on day 10 and dinoflagellates on day 18, whereas no clear trend was recorded at Cabo Frio Island （an undisturbed area）. The ennoblement of Ecor values was site-dependent. In a complementary laboratory assay, biofilms were removed and the Eco values registered in sterile conditions for the subsequent 10 days and corroborated in situ results. Understanding biofilms and SS interactions has important implications for materials science and engineering decisions as well as helping to fill in imnortant gaps in this knowledge.     

Estimates of vertical mixing during a Lagrangian experiment off the Galician coast

An adjoint 1-D model was used to determine vertical diffusivity coefficients from temperature profiles collected within a filament escaping from the Galician coast following an upwelling event. The optimisation scheme ended with relatively high diffusivity values within the thermocline (9×10⁻⁵ m² s⁻¹). Such high values are relevant for biogeochemical exchanges between surface and deep waters in stratified areas.The optimised values were several orders of magnitude higher than the bulk of diffusivity measurements recorded with a free-falling device; however, the optimisation solution was consistent with the arithmetic mean of the measurements in the thermocline (7.7×10⁻⁵ m² s⁻¹), giving more weight to the few largest values. Below the thermocline, the data assimilation method failed because of the three-dimensional nature of the advective field of the upwelling system. Ignoring this advective forcing in the model led to estimates that were two orders of magnitude too high.The results suggest that turbulent mixing is a random process where a few intense events determine the average mixing that drives the long-term evolution of the water column structure. This statistical property is very important when one wants to use instantaneous diffusivity measurements for modelling purposes.     

Damper Models for Heavy Vehicle Ride Dynamics

A laboratory rig for testing hydraulic dampers using the 'hardware-in-the-loop' method is described, and the accuracy of the test method is investigated. A mathematical model of a hydraulic shock absorber is then developed. The model is suitable for vehicle simulations and has seven parameters which can be determined by simple dynamic measurements on a test damper. The shock absorber model is validated under realistic operating conditions using the test rig, and the relative importance of various features of the model on the accuracy of vehicle simulations is investigated.