Isam Kaysi

THE IMPACT OF PREDICTIVE INFORMATION ON GUIDANCE EFFICIENCY : AN ANALYTICAL APPROACH

The acceptance of route guidance advice by motorists is expected, to occur only whenever such advice is experienced to be valid and reliable. Three major factors may cause route guidance systems to provide motorists with unreliable advice: (1) the traffic information constituting the basis for guidance advice is inaccurate; (2) the impact of a large fraction of motorists responding to the guidance, and the subsequent overreaction that occurs, is ignored whenever the guidance advice is being set; and, (3) concentration effects may occur and induce a higher level of (unpriced) congestion when drivers are provided with better information.

EFFECT OF ROADWAY NETWORK AGGREGATION LEVELS ON MODELING OF TRAFFIC-INDUCED EMISSION INVENTORIES IN BEIRUT

Abstract Traffic-induced emissions pose a serious threat to air quality in heavily congested urban centers. While air quality can be characterized through field measurements and continuous monitoring, forecasting future conditions depends largely on estimating vehicle-emission factors coupled with mathematical modeling. Traffic and environmental planners have relied on overall average network speed in conjunction with speed-based emission factor models to estimate traffic emissions. This paper investigates the effect of three levels of roadway network aggregation, macro-scale (overall network basis), meso-scale (roadway functional class basis) and micro-scale (link-by-link basis) on emission inventories. A traffic model and an emission factor model were integrated to determine total emissions in the future Beirut Central District area for these three modeling approaches.

Design Aspects of Advanced Traveler Information Systems

The acceptance of route guidance advice by motorists is expected to occur only whenever such advice is experienced to be valid and reliable. Two factors may cause route guidance systems to provide motorists with unreliable advice: (1) the traffic information constituting the basis for guidance advice is inaccurate; and, (2) the impact of a large fraction of motorists responding to the guidance, and the subsequent overreaction that occurs, is ignored whenever the guidance advice is being set.

Modeling anger and aggressive driving behavior in a dynamic choice–latent variable model

This paper develops a hybrid choice-latent variable model combined with a Hidden Markov model in order to analyze the causes of aggressive driving and forecast its manifestations accordingly. The model is grounded in the state-trait anger theory; it treats trait driving anger as a latent variable that is expressed as a function of individual characteristics, or as an agent effect, and state anger as a dynamic latent variable that evolves over time and affects driving behavior, and that is expressed as a function of trait anger, frustrating events, and contextual variables (e.g., geometric roadway features, flow conditions, etc.). This model may be used in order to test measures aimed at reducing aggressive driving behavior and improving road safety, and can be incorporated into micro-simulation packages to represent aggressive driving. The paper also presents an application of this model to data obtained from a driving simulator experiment performed at the American University of Beirut. The results derived from this application indicate that state anger at a specific time period is significantly affected by the occurrence of frustrating events, trait anger, and the anger experienced at the previous time period. The proposed model exhibited a better goodness of fit compared to a similar simple joint model where driving behavior and decisions are expressed as a function of the experienced events explicitly and not the dynamic latent variable.

Commodity-Based Truck Origin-Destination Matrix Estimation Using Input-Output Data and Genetic Algorithms

A commodity-based model to estimate a truck origin-destination (O-D) matrix is presented. The model takes advantage of the genetic algorithm global search method to find the best O-D matrix that when assigned to the network gives the minimum deviation between observed and estimated data. The model is flexible with respect to the type of data used in estimating the O-D matrix; however, the case study presented in this paper takes into consideration only two sets of information: commodity flow on specific links and column and row sums of the O-D matrix. Flows are treated as commodity dollar value; therefore, the estimated O-D matrix entries consist of the value of the commodity shipped by truck from the origin zone to the destination zone. The method is composed of two submodels. The first submodel, the trip generation model, uses input-output data with employment and population data to estimate the zonal level of commodity attraction and production. The second submodel, the genetic algorithm model, searche...

Traveler Information Provision for Incident Management: Implications for Vehicle Emissions

The potential of intelligent transportation systems (ITS) in alleviating nonrecurring traffic congestion was assessed, and then the resulting implications for vehicle-induced emissions in a congested city in a developing country were estimated. This work provides a blueprint for future studies on both the evaluation of ITS deployment through dynamic traffic modeling and the assessment of resulting changes in travel times and emissions. The Greater Beirut, Lebanon, area road network was used as the test bed for evaluating strategies for incident management, which was the selected ITS application for this study. A series of simulation scenarios was conducted with dynamic traffic-simulation-assignment methodology, and resulting emissions were estimated with an emission-factor model. These scenarios were used to evaluate the effect of different ITS deployment parameters—such as type of information provision (pretrip and in-vehicle) and driver compliance—on network performance and resulting emissions. Network performance measures such as travel and stop times were developed, and corresponding vehicle emissions were estimated with carbon monoxide, nitrogen oxides, and total organic carbon as indicators for each scenario.

PHASING OUT LEAD IN AUTOMOTIVE FUELS: CONVERSION CONSIDERATIONS, POLICY FORMULATION, AND APPLICATION TO LEBANON

Abstract The serious public health effects of lead are widely recognized, and many countries of the world have taken steps to completely eliminate it from automotive fuels. This study reviews the international experience with phasing out leaded gasoline; considerations affecting adoption of unleaded fuel are identified, and difficulties underlying change are synthesized. Factors related to technology, supply availability, distribution channels, economics, and social equity are underlined. International experience is distilled into a set of desirable characteristics of policies for phasing out leaded fuel. Such desirable properties include robustness vis-a-vis enforcement and compliance, the existence of a few “control points”, flexibility with respect to future vehicle and fuel technologies, cost-neutrality, and fairness in terms of incidence on socio-economic groups. The case of Lebanon is considered in structuring a practical strategy for phasing out leaded fuel. Positive and negative factors likely to affect the success of lead phaseout strategies in Lebanon are identified. Consideration of these factors along with the desirable attributes of successful policies has led to the development of a recommended plan for leaded fuel phaseout.

Geotechnical and environmental considerations in highway layouts: an integrated GIS assessment approach

Highway route layout design typically relies on aerial photographs, topographic maps and geologic maps. In this paper, a GIS platform, which incorporates the main digital data needed for evaluating route layouts, is used in a computer-based approach for highway layout assessment. Possible layouts are evaluated based on two sets of criteria. First, traditional evaluation criteria focussing on geometric design factors and impact on man-made features are considered. Next, the developed assessment framework builds on the GIS platform to generate specific environmental and geotechnical criteria for route layout evaluation. The developed approach integrates highway design, slope stability, and traffic noise modeling packages and specifically written codes with the GIS packages ARC/INFO and ArcView. A prototypical application of the assessment framework for a proposed highway south of the city of Beirut, Lebanon is presented. The results demonstrate the potential of the developed approach in incorporating new evaluation criteria at the route layout design stage and in automating the route layout assessment procedure.

An Integrated Model for Resource Allocation and Scheduling in a Transshipment Container Terminal

Abstract This paper considers the coordination between quay cranes and yard cranes in a transshipment process at a container terminal. An optimization model (a linear-integer program) is developed to minimize the number of cranes used in both the quay and yard sides. In addition, the developed model determines the optimal schedule for unloading a vessel and storing its transshipment containers in the yard as a function of the container location in ship bay, type of container (e.g., weight class, size, and next port of destination), and the yard sub-block allocated for every container. The model is solved using the GUROBI solver via AMPL compiler. Numerical results are presented to illustrate the application of the model and draw insights. Our main insight is that, under coordination between the quay and yard sides, constraints on one side may significantly affect the allocation and scheduling of cranes on the other side.

ALLOCATION OF RISKS UNDER BUILD-OPERATE-TRANSFER DELIVERY APPROACH FOR TRANSPORT INFRASTRUCTURE PROJECTS

The need for the build-operate-transfer (BOT) approach in the development of infrastructure projects has risen in recent years, due to budgetary and financial constraints faced by the public sector in both developing and developed countries, tightened by the necessity to repair, maintain, and modernize the existing infrastructure facilities. Risk factors that influence the parties of a prospective BOT contract during the various phases of the contract are presented. In particular, the factors pertaining to the precontract stage and to the political, construction, commercial, and financial categories of possible risks are addressed. Integrated schemes assimilating the risks involved and the corresponding alleviation measures are offered.