Problem: Localities and states are turning to land planning and urban design for help in reducing automobile use and related social and environmental costs. The effects of such strategies on travel demand have not been generalized in recent years from the multitude of available studies. Purpose: We conducted a meta-analysis of the built environment-travel literature existing at the end of 2009 in order to draw generalizable conclusions for practice. We aimed to quantify effect sizes, update earlier work, include additional outcome measures, and address the methodological issue of self-selection. Methods: We computed elasticities for individual studies and pooled them to produce weighted averages. Results and conclusions: Travel variables are generally inelastic with respect to change in measures of the built environment. Of the environmental variables considered here, none has a weighted average travel elasticity of absolute magnitude greater than 0.39, and most are much less. Still, the combined effect o...

/pdf/travel-and-the-built-environment-1ankek9s8z.pdf

Travel and the Built Environment

Carbon capture and storage (CCS) is broadly recognised as having the potential to play a key role in meeting climate change targets, delivering low carbon heat and power, decarbonising industry and, more recently, its ability to facilitate the net removal of CO2 from the atmosphere. However, despite this broad consensus and its technical maturity, CCS has not yet been deployed on a scale commensurate with the ambitions articulated a decade ago. Thus, in this paper we review the current state-of-the-art of CO2 capture, transport, utilisation and storage from a multi-scale perspective, moving from the global to molecular scales. In light of the COP21 commitments to limit warming to less than 2 °C, we extend the remit of this study to include the key negative emissions technologies (NETs) of bioenergy with CCS (BECCS), and direct air capture (DAC). Cognisant of the non-technical barriers to deploying CCS, we reflect on recent experience from the UK's CCS commercialisation programme and consider the commercial and political barriers to the large-scale deployment of CCS. In all areas, we focus on identifying and clearly articulating the key research challenges that could usefully be addressed in the coming decade.

/pdf/carbon-capture-and-storage-ccs-the-way-forward-11rgsqyer0.pdf

Carbon capture and storage (CCS): the way forward

Energy is a vital input for social and economic development. As a result of the generalization of agricultural, industrial and domestic activities the demand for energy has increased remarkably, especially in emergent countries. This has meant rapid grower in the level of greenhouse gas emissions and the increase in fuel prices, which are the main driving forces behind efforts to utilize renewable energy sources more effectively, i.e. energy which comes from natural resources and is also naturally replenished. Despite the obvious advantages of renewable energy, it presents important drawbacks, such as the discontinuity of generation, as most renewable energy resources depend on the climate, which is why their use requires complex design, planning and control optimization methods. Fortunately, the continuous advances in computer hardware and software are allowing researchers to deal with these optimization problems using computational resources, as can be seen in the large number of optimization methods that have been applied to the renewable and sustainable energy field. This paper presents a review of the current state of the art in computational optimization methods applied to renewable and sustainable energy, offering a clear vision of the latest research advances in this field.

Optimization methods applied to renewable and sustainable energy: A review

Logistics integration and network orientation in the port and maritime industry have redefined the functional role of ports in value chains and have generated new patterns of freight distribution and new approaches to port hierarchy. Existing models on the spatial and functional evolution of ports and port systems only partially fit into the new freight distribution paradigm. This paper aims to add to existing literature by introducing a port regionalization phase in port and port system development. It is demonstrated that the regionalization phase and associated hinterland concepts demand new approaches to port governance and a functional focus that goes beyond the traditional port perimeter.

Port regionalization: towards a new phase in port development

http://yoksis.bilkent.edu.tr/doi_getpdf/articles/10.1016-j.ejor.2007.06.008.pdf

Network hub location problems : The state of the art

Beginning with Hodgson (Geogr.Anal.22(1990) 270), several researchers have been developing a new kind of location-allocation model for “flow capturing.” Instead of locating central facilities to serve demand at fixed points in space, their models aim to serve demand consisting of origin-destination flows along their shortest paths. This paper extends flow-capturing models to optimal location of refueling facilities for alternative-fuel (alt-fuel) vehicles, such as hydrogen fuel cells or natural gas. Existing flow-capturing models assume that if a flow passes just one facility along its path, it is covered. This assumption does not carry over to vehicle refueling because of the limited range of vehicles. For refueling, it may be necessary to stop at more than one facility in order to successfully refuel the entire path, depending on the vehicle range, the path length, and the node spacing. The Flow Refueling Location Model (FRLM) optimally locates p refueling stations on a network so as to maximize the total flow volume refueled. This paper presents a mixed-integer programming formulation for the nodes-only version of the problem, as well as an algorithm for determining all combinations of nodes that can refuel a given path. A greedy-adding approach is demonstrated to be suboptimal, and the tradeoff curve between number of facilities and flow volume refueled is shown to be nonconvex.

The flow-refueling location problem for alternative-fuel vehicles

Many US cities have recently built or approved light-rail systems to combat congestion, sprawl, and pollution. Critics questions light rail’s ability to generate ridership in low-density, automobile-oriented, polycentric US cities with smaller downtowns. Proponents counter that sufficient numbers of homes and workplaces have convenient access to stations via walking, park-and-ride, or bus to develop feasible corridors connecting major residential areas with suburban concentrations of employment and the CBD. With this in mind, we used multiple regression to determine factors that contribute to higher light-rail ridership. Cross-sectional data on average weekday boardings were collected for the year 2000 for 268 stations in nine US cities representing a variety of urban settings. The results showed the importance of land use and accessibility. Employment, population, and percent renters within walking distance, as well as bus lines, park-and-ride spaces, and centrality, were significant. Dummy variables for terminal and transfer stations and international borders were all positive and significant. Total degree-days were negative and significant, lowering expectations for cities with extreme climates. Notably, the stations in the CBD generate much higher boardings, but these are explainable by the same variables present in lesser combinations at non-CBD stations and account for their generally lesser boardings. Importantly, a dummy variable for CBD location was not significant. The resulting model may be useful as a first-cut, one-step approach for predicting demand for possible light-rail alignments.

Factors influencing light-rail station boardings in the United States

Increased interest in alternative fuels is attributable, in part, to rising oil prices and increasing concern about global warming. A lack of a refueling infrastructure, however, has inhibited the adoption of alternative-fuel vehicles. Little economic incentive exists to mass-produce alternative-fuel vehicles until a network of stations exists that can refuel a reasonable number of trips. The flow refueling location model (FRLM) was developed to minimize the investment necessary to create a refueling infrastructure by optimizing the location of fueling stations. The original uncapacitated FRLM assumes that the presence of a refueling station is sufficient to serve all flows passing through a node, regardless of their volume. This article introduces the capacitated flow refueling location model that limits the number of vehicles refueled at each station. It also introduces a modified objective function maximizing vehicle-miles traveled instead of trips, applies both models to an intercity network for Arizona, and formulates several other extensions.



El creciente interes por combustibles alternativos es atribuible en parte al incremento del precio del petroleo y a la preocupacion por el calentamiento global. La insuficiente infraestructura de estaciones de servicio de dichos combustibles ha inhibido la adopcion de vehiculos que los usan. Por otro lado, hay pocos incentivos economicos para producir estos vehiculos, por lo menos hasta que se establezca una red de estaciones que permita el reabastecimiento de combustibles alternativos y a la vez minimice el numero de viajes. El modelo de localizacion de flujo y reabastecimiento (FRLM) fue desarrollado por los autores para minimizar la inversion necesaria para crear una infraestructura de reabastecimiento por medio de la optimizacion de la ubicacion de las estaciones. En su version original, el FRLM asume que la presencia de una estacion es suficiente para (re)abastecer la demanda de todos los flujos (vehiculos) que atraviesan dicho nodo de la red sin importar el volumen del flujo en si. El presente articulo propone el uso de nuevo modelo: el CFRLM, el cual pone un limite al numero de vehiculos que pueden ser abastecidos por cada estacion. Asimismo, el modelo sugerido presenta una modificacion a la funcion objetivo que maximiza el numero de millas recorridas en lugar del numero de viajes. Ambos modelos son aplicados a la red vial que conecta varias ciudades del estado de Arizona (EEUU). Adicionalmente se presentan diversas variaciones y extensiones a los modelos que permiten y sugieren futuras aplicaciones.



石油价格的上涨和对全球变暖问题愈来愈多的关注，某种程度上导致了人们对可替代性燃料的重视。然而，替代燃料供给基础设施的缺乏，制约了使用替代燃料的交通工具的推广。除非建立合理的替代燃料供给站网络，否则对替代燃料车辆的大规模生产的经济推动作用甚微。流量加油选址模型(FRLM) 通过对燃料供给站选址的优化，使得建造燃料供给基础设施的投资最小。原来的FRLM模型没有容量限制，即假定不论行经车辆的实际需求量有多大，任何一个加油点均能提供足够多的燃料以满足其需求。本文引入了一种具有容量限制的流量加油选址模型（CFRLM）,能够对每个加油站的加油车辆数目进行限制。此外，本文还提出了一种改进的目标函数对车辆行驶里程而非行程求最大值，并将这两种模型应用于亚利桑那州城市间的加油站网络分析。作者还阐述了在其它一些方面的推广应用。

https://www.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1538-4632.2009.00744.x

Michael Kuby

Papers

The flow-refueling location problem for alternative-fuel vehicles

Factors influencing light-rail station boardings in the United States

A Model for Location of Capacitated Alternative-Fuel Stations

The deviation-flow refueling location model for optimizing a network of refueling stations

Optimization of hydrogen stations in Florida using the Flow-Refueling Location Model