Hailing a change: comparing taxi and ridehail service quality in Los Angeles

Transportation - For decades, taxis have provided for-hire vehicle service without significant competition from other modes. But in 2012, ride-hail services such as Uber and Lyft upended the taxi...     

Demand management of congested public transport systems: a conceptual framework and application using smart card data

Transportation - Transportation demand management, long used to reduce car traffic, is receiving attention among public transport operators as a means to reduce congestion in crowded public...     

A simplified grounding damage prediction method and its application in modern damage stability requirements

This paper presents the analyses and results aimed at developing damage stability requirements which take into account the structural vulnerability to grounding damage, i.e. the kinetic energy available to generate damage and the structural resistance. The paper presents analysis of new damage statistics in order to determine impact scenarios, in particular in terms of impact speed, impact location, and width and height of damage. Furthermore a new empirical damage prediction formula is developed based on a combination of full-scale testing and extensive non-linear finite element analyses. This deterministic prediction method is validated against grounding experiments and then used in a probabilistic (Monte Carlo) simulation framework. First the simulation method is calibrated and validated against the real statistical damage data for conventional ships and then it is used to generate damage statistics for high-speed craft. It turns out that the grounding damage statistics for all ships can be characterized by a single parameter; the Grounding Damage Index, GDI, which includes the ship kinetic energy and its structural resistance to grounding damage. Simple, closed-form expressions are developed for the GDI and it is shown how the probability of exceeding a box-shaped damage is a simple function of the GDI and the size of the box. The paper therefore gives the background and the results for a new generation of damage stability rules where the structural crashworthiness is taken into account and where the passive safety level is explicitly expressed. It furthermore gives simplified prediction tools and data for actual ships, i.e. a toolbox that is readily available for risk analysis regarding grounding damage.     

Employment suburbanisation, reverse commuting and travel behaviour by residents of the central city in the Paris metropolitan area

This paper analyses the relationship between employment suburbanisation in the Paris metropolitan area, the growth of reverse commuting and changes in the weekday travel behaviour of working residents of the central city over a 20-year period. The results show that the number of reverse commuters has significantly increased because the municipality of Paris has lost many jobs but few working residents whilst employment has developed in the suburbs. Reverse commuters are mainly and increasingly high-income professionals whose workplace is located close to the central city in employment sub-centres that are well served by public transport. Consequently reverse commuters have lower than average car use although differences exist and are related to their professional status. The policy implications of these findings are discussed in the conclusion.     

The relative contribution of transportation to supply chain greenhouse gas emissions: A case study of American wheat

This life cycle assessment case study puts the supply chain contribution of transportation to greenhouse gas emissions in context with other contributors using American wheat grain as a representative product. Multiple locations, species and routes to market are investigated. Transportation contributes 39–56% of the supply chain emissions, whereas there is a 101% intra-species and 62% inter-species variation in greenhouse gas emissions from production, demonstrating that transportation is both of smaller magnitude, and less sensitive than other factors, in particular, field sequestration.     

Analyzing voter support for California’s local option sales taxes for transportation

Local and regional governments in the U.S. rely increasingly on voter-approved local option sales taxes (LOSTs) to fund transportation capital investments, maintenance, and operations. LOSTs typically present voters with lists of local transportation projects and programs to be funded by a ¼ to 1 percent sales tax increase. Most research on LOSTs are case studies, which make generalizations about LOSTs difficult. We conducted a comprehensive, multi-jurisdictional analysis of LOST measures in California, the U.S. state with the greatest number of LOST measures. We examined 76 LOST measures put to voters between 1976 and 2016 to assess factors associated with voter support. LOSTs in California are enacted by counties, which we examined in addition to smaller intra-county geographies using both regression models and case studies. We tested several explanatory variables for association with voter support including macroeconomic and political context, planned measure expenditures, voter characteristics, and spatial distribution of proposed projects. We found that funding dedicated to public transit and returned to local jurisdictions predicts support at the county level, and that LOSTs that create new taxes—as opposed to extending or renewing existing taxes—are less popular with voters, all else equal. Our analyses of sub-county geographies revealed that political party affiliation is the strongest predictor of local voter support for LOSTs and that voters living adjacent to funded projects tended to be more supportive of LOSTs.

     

Incident reporting in Finnish shipping companies

The purpose of the International Safety Management Code (the ISM Code) is to promote safety culture in the maritime industry. Learning the lessons from incidents should help to improve safety performance since incidents and accidents can share the same root causes. The aim of this paper is to take a closer look at incident reporting in the Finnish shipping industry, to study the reasons for poor incident reporting and to suggest improvements to increase reporting. The paper consists of a literature study, which focuses on previous studies concerning incident reporting, and an interview study, which focuses on Finnish shipping companies and their personnel. The interview study confirmed that incident reporting does not function properly within the Finnish maritime industry. The maritime personnel have an occupational culture which is incompatible with the rule-based safety management approach provided by the ISM Code. The willingness to report incidents could be increased if all seafarers were involved in the reporting process and the preparation of corrective actions. In addition, the reporting procedures should be streamlined and developed to a more user-friendly direction.     

Identification and assessment of aquatic resources for power plant sites on Maryland's Eastern shore

Abstract

A power plant siting procedure which accounts for the protection and preservation of aquatic resources, defined as sensitive life forms and life stages of economically valuable species of finfish and shellfish, is presented as it was executed on Maryland's Eastern Shore. Negative effects of power plant development and operation are generated principally by the cooling water intake and discharge system. The site‐selection procedure is thus presented as a two‐faceted process, termed regional screening, requiring the separate but simultaneous identification of land‐based sites and cooling systems. Criteria included in regional screening for cooling systems reflected life‐sustaining processes essential to the maintenance of aquatic resources. Major sources of effects of power plants on aquatic resources and siting principles as they affect aquatic resources are defined. Information‐gathering techniques included extensive interviews with key research scientists, state personnel, and numerous Chesapeake Bay watermen.     

Transport-related CO2 effects of online and brick-and-mortar shopping: A comparison and sensitivity analysis of clothing retailing

This paper compares transport-related CO₂ emissions of online and brick-and-mortar shopping based on supply, delivery, order and travel data related to one multi-channel clothing retailer. A sensitivity analysis sheds more light on how situational factors, such as the customers’ travel distances, returns, the use of public transport modes and information behavior via different channels influence the outcome of this comparison. The results show that online retailing causes lower CO₂ emissions under many conditions. Nevertheless, the brick-and-mortar channel is more environmentally friendly when travel distances are small. The radius for which brick-and-mortar shopping has an advantage increases when returns, shifts in the use of public transport and information behavior are also considered.     

Ventilation System Heating Demand Forecasting Based on Long Short-Term Memory Network

Load forecasting can increase the efficiency of modern energy systems with built-in measuring systems by providing a more accurate peak power shaving performanc...