Modeling Driver\u27s Route Choice Behavior Under the Influence of Advanced Traveler Information Systems (Vol. 2; Vol. 1: 96/10)

This research consisted of two parts; this report is volume 2 of 2 volumes; Volume 1 is Report No. FHWA/IN/JHRP-96/10. The first part developed a set of incident clearance time prediction models for the Borman Expressway. The second part consisted of modeling driver’s route choice behavior under the influence of advanced traveler information systems. Volume 2 of this report describes the modeling driver\u27s route choice behavior under the iinfluence of Advanced Traveler Information Systems. These models can help in understanding the behavior and response of travelers under the influeince of Advanced Traveler Information Systmes.r The products of this research project will be incorpored in the Advanced Traffic Managment System that is being implemented on the Morman Expressway, a 16-mile segment of *-80 n northwest Indiana

Network-Level Reliability-Based Bridge Inspection, Maintenance and Replacement Optimization Model

This paper presents a reliability-based optimization model of inspection, maintenance and replacement for a system of several highway bridges. The objective in the formulation is to minimize the total expected social cost, including the expected cost of failure. The frequency of inspections is included as a decision variable. The probability of failure is explicitly taken into account in the constraints. A bottom-up approach is used, which allows for bridge-specific details to be taken into account. Most existing system level models assume that component deterioration is memoryless; however, this assumption is relaxed in this paper, and history-dependent deterioration models are used. The formulation is flexible enough to accommodate different types of facilities, deterioration processes and failure modes. A parametric study is conducted to demonstrate the model’s response to different assumptions on the deterioration rates, maintenance costs and efficiency

Freeway Incident Likelihood Prediction and Response Decision-Making

This research project consisted of two parts. The first part developed a set of real-time incident likelihood prediction models. The second part developed a freeway incident response decision-making methodology based on sequential hypothesis testing methods. The freeway incident likelihoods predicted by the real-time prediction models act as prior probabilities for the freeway incident response decision-making system. The products of this research project will be incorporated in the Advanced Traffic Management System that is being implemented on the Borman Expressway, a 16-mile segment of I-80 in northwest Indiana. The decision-making system can be used by traffic management personnel to assist in responding to various freeway incidents in a near optimal manner to minimize traffic delays and reduce the number of secondary incidents

Accounting for Endogeneity in Maintenance Decisions and Overlay Thickness in a Pavement-Roughness Deterioration Model

Pavement deterioration models are an important part of any pavement management system. Many of these models suffer from endogeneity bias because of the inclusion of independent variables correlated with unobserved factors, which are captured by the model's error terms. Examples of such endogenous variables include pavement overlay thickness and maintenance and rehabilitation activities, both of which are not randomly chosen but are in fact decision variables selected by pavement engineers based on field conditions. Inclusion of these variables in a pavement deterioration model can result in biased and inconsistent model parameter estimates, leading to incorrect insights. Previous research has shown that continuous endogenous variables, such as pavement overlay thickness, can be corrected using auxiliary models to replace the endogenous variable with an instrumented variable that has lower correlation with the unobserved error term. Discrete endogenous variables, such as the type of maintenance and rehabilitation activities, have been accounted for by modeling the likelihood of each potential outcome and developing individual deterioration models for each of the potential responses. This paper proposes an alternative approach to accommodate discrete endogenous variables-the selectivity correction method-that allows a single model to incorporate the impacts of all discrete choices. This approach is applied to develop a pavement-roughness progression model that incorporates both continuous and discrete endogenous variables using field data from Washington State. The result is a roughness progression model with consistent parameter estimates, which have more realistic values than those obtained in previous studies that used the same data

Green Synthesis of Silver Nanoparticles Using Hypericum perforatum L. Aqueous Extract with the Evaluation of Its Antibacterial Activity against Clinical and Food Pathogens

The rapid development of nanotechnology and its applications in medicine has provided the perfect solution against a wide range of different microbes, especially antibiotic-resistant ones. In this study, a one-step approach was used in preparing silver nanoparticles (AgNPs) by mixing silver nitrate with hot Hypericum perforatum (St. John’s wort) aqueous extract under high stirring to prevent agglomeration. The formation of silver nanoparticles was monitored by continuous measurement of the surface plasma resonance spectra (UV-VIS). The effect of St. John’s wort aqueous extract on the formation of silver nanoparticles was evaluated and fully characterized by using different physicochemical techniques. The obtained silver nanoparticles were spherical, monodisperse, face-centered cubic (fcc) crystal structures, and the size ranges between 20 to 40 nm. They were covered with a capping layer of organic compounds considered as a nano dimension protective layer that prevents agglomeration and sedimentation. AgNPs revealed antibacterial activity against both tested Gram-positive and Gram-negative bacterial strains causing the formation of 13–32 mm inhibition zones with MIC 6.25–12.5 µg/mL; Escherichia coli strains were resistant to tested AgNPs. The specific growth rate of S. aureus was significantly reduced due to tested AgNPs at concentrations ≥½ MIC. AgNPs did not affect wound migration in fibroblast cell lines compared to control. Our results highlighted the potential use of AgNPs capped with plant extracts in the pharmaceutical and food industries to control bacterial pathogens’ growth; however, further studies are required to confirm their wound healing capability and their health impact must be critically evaluate

Optimal policies for greenhouse gas emission minimization under multiple agency budget constraints in pavement management

Greenhouse gas emissions reduction has garnered special importance in recent times in the transportation sector, including pavement design and management. In this study, we incorporate this environmental objective in pavement management. We present an optimization problem to minimize GHG emissions under multiple budget constraints by determining joint management strategies for a range of heterogeneous interventions, including maintenance, rehabilitation and reconstruction. We propose a computationally efficient bottom-up solution algorithm, which is built on Lagrangian Relaxation and Dynamic Programming. Finally, we apply our findings to a real-world highway network in California, where the results show a potential GHG emissions reduction of 20% through an increased combined budget of 35% on the Pareto frontier

Planning hierarchical urban transit systems for reductions in greenhouse gas emissions

Public transit systems with high occupancy can reduce greenhouse gas (GHG) emissions relative to low-occupancy transportation modes, but current transit systems have not been designed to reduce environmental impacts. This motivates the study of the benefits of design and operational approaches for reducing the environmental impacts of transit systems. For example, transit agencies may replace level-of-service (LOS) by vehicle miles traveled (VMT) as a criterion in evaluating design and operational changes. In previous work, we explored the unintended consequences of lowering transit LOS on emissions in a single-technology transit system. Herein, we extend the analysis to account for a more realistic case: a transit system with a hierarchical structure (trunk and feeder lines) providing service to a city where demand is elastic. By considering the interactions between the trunk and the feeder systems, we provide a quantitative basis for designing and operating integrated urban transit systems that can reduce GHG emissions and societal costs. We find that highly elastic transit demand may cancel emission reduction potentials resulting from lowering LOS, due to demand shifts to lower occupancy vehicles. However, for mass transit modes, these potentials are still significant. Transit networks with buses, bus rapid transit or light rail as trunk modes should be designed and operated near the cost-optimal point when the demand is highly elastic, while this is not required for metro. We find that the potential for unintended consequences increases with the size of the city. Our results are robust to uncertainties in the costs and emissions parameters

Prediction Models for Incident Clearance Time for Borman Expressway (Vol. 1; Vol. 2: 96/11)

This research consisted of two parts; this report is Volume 1 of 2 Volumes; Volume 2 is Report No. FHWA/IN/JHRP-9611. The first part developed a set of incident clearance time prediction models for the Borman Expressway. The second part consisted of modeling driver’s route choice behavior under the influence of advanced traveler information systems. Volume 1 of this report describes the incident clearance time prediction models for the Borman Expressway. The prediction of incident clearance time from these models can facilitate in efficient incident management and support traveler information systems. The products of this research project will be incorporated in the Advanced Traffic Management System that is being implemented on the Borman Expressway, a 16-mile segment of I-80 in northwest Indiana