Computing the cost of traffic congestion: a microsimulation exercise of the City of Antofagasta,Chile

Abstract

This paper computes the cost of traffic congestion in the city of Antofagasta in Chile. A microsimulation is implemented where all the agents of the system travel across the transport network. The congestion cost is computed through the aggregation of the opportunity cost of people waiting within the transport system, as a consequence of traffic congestion. Monte Carlo experiments produced an approximated congestion cost of US$1.02 million during a typical working day. Moreover, the simulation provides useful information about the average traveling time for the 14 districts of the city.     

Book Review: Airline Marketing and Management

Abstract

Public transport policy in the Madrid Metropolitan Area is often deemed as a success. In 1985, an important reform was carried out in order to create a new administrative authority to coordinate all public transport modes and establish a single fare for all of them. This reform prompted a huge growth in public transport usage, even though it reduced the funding coverage ratio of the transport system. Since then, Madrid’s public transport system has been undergoing an increasing level of subsidization, which might jeopardize the financial viability of the city public transport system in the future. In this paper, we present a detailed analysis of the evolution of the public transport funding policy in Madrid in recent years. We found that the increasing level of subsidy can hardly be explained on the basis of equity issues. Moreover, we claim that there is still room for a funding policy that makes the efficiency of the system compatible with its financial sustainability.     

Inclusion of latent variables in Mixed Logit models: Modelling and forecasting

Travel demand models typically use mainly objective modal attributes as explanatory variables. Nevertheless, it has been well known for many years that attitudes and perceptions also influence users’ behaviour. The use of hybrid discrete choice models constitutes a good alternative to incorporate the effect of subjective factors. We estimated hybrid models in a short-survey panel context for data among many alternatives. The paper analyses the results of applying these models to a real urban case study, and also proposes an approach to forecasting using these models. Our results show that hybrid models are clearly superior to even highly flexible traditional models that ignore the effect of subjective attitudes and perceptions.     

Effect of advanced traveler information systems and road pricing in a network with non-recurrent congestion

The effect of the application of advanced transport information system (ATIS) and road pricing is studied in a transportation system under non-recurrent congestion. A stochastic network deterministic user equilibrium model (SNDUE) with elastic demand is formulated and used to evaluate the welfare and private impacts of different market penetrations of ATIS, together with road pricing for a simple network. Both marginal first-best road pricing and a second-best fixed road pricing are considered. The incentives of private users to use ATIS are analyzed and the characteristics of optimum tolls as a function of ATIS market penetration are shown. We conclude that ATIS is an efficient and necessary tool to reduce the effects of non-recurrent incidents in a transportation network, especially when non-recurrent congestion causes a significant deterioration of operational conditions of the network. If the impact of non-recurrent incidents on free flow costs is small or is reduced only to congestion effects, the use of road pricing would be more efficient. Social benefits obtained when jointly implementing ATIS and road pricing are practically the same whether first-best or second-best road pricing is used. Considering the private costs perceived by the network users, and the benefits experienced by equipped users, the maximum level of market penetration achieved could be limited because private benefits disappear after certain market penetration is obtained.     

Sail optimization for upwind sailing: application in a Tornado, the Olympic class catamaran

A study of a boat's motion is carried out in order to analyze the aerodynamic properties of the optimal sail for obtaining the maximum velocity when sailing to windward. The mechanics study shows the optimal C _L and C _D for a given sail and how the shape of the aerodynamic polar of the sail should be. A parametrical analysis of the aerodynamics of a sail is then carried out varying the maximum camber, position of the maximum camber in the chord direction and position of the maximum camber in the mast direction. The parametric analysis is done numerically with a vortex lattice method (VLM) and experimentally in a wind tunnel. The results show that the influence of the relevant parameters studied can be reduced to the variation of two parameters, A and B, defining the polar of the sail, C _D = B + A ² C _L ²; and the influence of parameters A and B on the maximum VMG obtainable are calculated.     

An assessment of port reform in Argentina: outcomes and challenges ahead

During the 1990s Argentina engaged in a process of restructuring and deregulation of its ports. The main objective of the reform was to increase efficiency and service quality and to reduce the size and role of the public sector in ports. Overall, it was expected to allow the transport sector to adjust its capacity to demand changes and to facilitate international trade while contributing to the reduction of the fiscal burden of this sector. This paper shows that the reform caused significant efficiency gains, allowing a 50% drop in container terminal handling price within five years in the most important ports. The paper also identifies outstanding issues that could impact the long-run sustainability of the gains achieved. Among these issues, emphasis is given to recent horizontal and vertical mergers in the Port of Buenos Aires and their consequences in terms of actual competition and access regulation.     

Estimation of a route choice model for urban public transport using smart card data

This paper describes a logit model of route choice for urban public transport and explains how the archived data from a smart card-based fare payment system can be used for the choice set generation and model estimation. It demonstrates the feasibility and simplicity of applying a trip-chaining method to infer passenger journeys from smart card transactions data. Not only origins and destinations of passenger journeys can be inferred but also the interchanges between the segments of a linked journey can be recognised. The attributes of the corresponding routes, such as in-vehicle travel time, transfer walking time and to get from alighting stop to trip destination, the need to change, and the time headway of the first transportation line, can be determined by the combination of smart card data with other data sources, such as a street map and timetable. The smart card data represent a large volume of revealed preference data that allows travellers' behaviour to be modelled with higher accuracy than by using traditional survey data. A multinomial route choice model is proposed and estimated by the maximum likelihood method, using urban public transport in ?ilina, the Slovak Republic, as a case study     

Merging ICT and informal transport in Jakarta's ojek system

This paper discusses how information and communication technologies (ICT) may influence travel behavior of an informal transport system, and whether and in which ways merging digital technologies represents disruption for a specific sociotechnical ensemble. For decades, ojek has been a form of informal passenger transport, based on motorcycles in Jakarta, and recently smartphone apps have become available in that sociotechnical arrangement. We randomly surveyed passengers and drivers in the central district, for both those who do and do not use these apps. Despite many similarities between both groups, the drivers who use smartphones for their trips reported higher daily incomes, longer average trip distances and a larger coverage area. Passengers using conventional ojek transport reported lower levels of both safety perception and satisfaction when compared to app-based ojek users. For both categories of user, ojek seems to compete with, complement, and be an alternative to bus rapid transit and the suburban rail system (KRL) in the area covered by our sample. The areas covered by regular buses and vans roughly match the origins and destinations of ojek trips.     

Late Holocene history of the rainfall in the NW Iberian peninsula—Evidence from a marine record

This study reconstructs climatic variability over the last 4700 yr in the NW Iberian Peninsula on the basis of lithological, sedimentological, biogeochemical, micropaleontological (diatoms and biosiliceous compounds) and AMS ¹⁴C analyses conducted in a gravity core retrieved from the Galician continental shelf. The core was recovered at the Galicia Mud Patch, a muddy sedimentary body highly influenced by the terrestrial supply of the Miño and Douro rivers, and thus controlled by the rainfall variations over the catchment area. River plume transports the lithogenic and continental-derived compounds to the shelf area allowing us to recognize several periods of terrestrial/marine influence. These periods are well correlated with the lithological units identified. Coarser sediments, high values of Ca/Al, low values of Fe, Al and lithogenic Si (LSi) are representative of the marine-influenced periods. These stages are related to dry conditions and winds coming from the NE under a NAO positive-like phase.Terrestrial-influenced stages are characterized by muddy sediments, with high content of Fe, Al and LSi, freshwater and benthic diatoms, continental-derived organisms (crysophycean cysts and phytoliths) and high amount of land-derived organic matter as reported by the C/N ratios. The influence of NAO positive- and NAO negative-like periods and solar activity are the two mechanisms quoted to explain the climatic variability during the last 4700 years.Proxies for the lithogenic input and terrigenous content (non-organic material) show an increase at around 2000–1800 cal. yr BP, linked to the warmer conditions and high precipitation patterns during the Roman Warm Period, and soil erosion due to forest degradation and other anthropic activities. A strong river flow event is recorded in shelf sediments during 800–500 cal. yr BP. A pervasive NAO negative-like period, and the high irradiance registered during the Grand Solar Maximum (GSM) controlled the precipitation and induced a high run-off and riverine influx during this event.     

Efficiency sensitivity analysis of a hydrostatic transmission for an off-road multiple axle vehicle

There is a large variety of multiple driven axle vehicles. Some of the most common are the 3-axle rigid vehicles and the 4-axle articulated vehicles, which can in some cases have different steering mechanisms, adaptive suspension, etc. This last kind of vehicles usually have very complex transmission configurations. Moreover, the required torques in each of the wheels can be very different, especially when the vehicle is working in rough terrains. The aim of this work is to study and model the driveline of this kind of vehicles, when using a hydrostatic transmission, from the performance and efficiency point of view, by analysing the influence of the operating conditions in the transmission efficiency. A global model is used to quantify the power flow in each of the transmission elements and the overall performance of the entire vehicle driveline, given the operating conditions thereof. A sensitivity analysis has also been done showing the influence of vehicle speed, rolling resistance, terrain slope and hydraulic motors displacement in the overall transmission efficiency. The interest of this work is also to make a contribution to the literature in the field of global modelling of drivelines under variable operating conditions and its application to ATVs. One important aspect is the influence of different actuation requirements that occur in different wheels at the same time. The results show that the overall performance of the transmission is highly dependent on operating conditions, on the selected transmission configuration and on the used components.