Papers by Omid M. Rouhani
MPRA Paper, 2014
This paper offers a general overview of the road pricing concept. It first examines the common ob... more This paper offers a general overview of the road pricing concept. It first examines the common objectives used in road pricing, namely (a) congestion reduction; (b) raising profits; (c) social welfare maximization; etc. Then, it explores various types of road pricing, including two major ones: (1) road tolls and (2) congestion pricing charges. Next, general modeling approaches used for estimating the impacts of road pricing are discussed. Finally, the paper concludes with a checklist explaining how to promote a successful road pricing scheme.
Advances in Automobile Engineering, 2021
Queue formation and dissipation have been extensively studied in relation to traffic signalizatio... more Queue formation and dissipation have been extensively studied in relation to traffic signalization, work zone operation, incident occurrence, and ramp metering. This study is an attempt to estimate the effect of vehicle mix, commute time, traffic direction, and road upgrade on queue dissipation speed (time). The data were collected at several intersections in Davis, California, U.S. and analyzed using regression models. The models were determined regressing several functional forms and considering the statistical significance and ease of interpretation of the included variables. The main findings are: 1) dissipation speed does not vary purely by location; 2) a heavy vehicle is faster to discharge than its passenger car sizeequivalent is; 3) the queue in a left-turn lane discharges faster than that in a through lane; 4) an upgrade slope increases the queue dissipation time due to more rolling resistance to vehicle start-up and larger vehicle gaps for safety ; 5) morning queues genera...
MPRA Paper, Feb 2, 2021
Building upon an earlier version, I further review the key methods to evaluate transportation pro... more Building upon an earlier version, I further review the key methods to evaluate transportation projects. Since transportation projects offer substantial social benefits and costs, it is vital to provide a comparative analysis on the commonly-used methods, i.e., which method(s) to use and under what conditions. In this short paper, I provide such analysis briefly.
Network design problem has been, and is, an important problem in transportation. Following an ear... more Network design problem has been, and is, an important problem in transportation. Following an earlier effort in designing a meta-heuristic search technique by an ant system, this paper attempts to hybridize this concept with other meta-heuristic concepts such as genetic algorithm, simulated annealing, and tabu search. Seven hybrids have been devised and tested on the network of Sioux Falls. It has been observed that the hybrids are more effective to solve the network design problem than the base ant system. Application of the hybrid containing all four concepts on a real network of a city with over 2 million population has also proved to be more effective than the base network, in the sense of finding better solutions sooner.
Journal of the Transportation Research Forum, Mar 1, 2014
The Transportation Research Forum, founded in 1958, is an independent, nonprofit organization of ... more The Transportation Research Forum, founded in 1958, is an independent, nonprofit organization of transportation professionals who conduct, use, and benefit from research. Its purpose is to provide an impartial meeting ground for carriers, shippers, government officials, consultants, university researchers, suppliers, and others seeking exchange of information and ideas related to both passenger and freight transportation. More information on the Transportation Research Forum can be found on the Web at www.trforum.org. Disclaimer: The facts, opinions, and conclusions set forth in this article contained herein are those of the author(s) and quotations should be so attributed. They do not necessarily represent the views and opinions of the Transportation Research Forum (TRF), nor can TRF assume any responsibility for the accuracy or validity of any of the information contained herein.
International Journal of Disaster Risk Reduction, 2017
Abstract Two major extreme-weather events occurred in New York State between 2011 and 2012. Each ... more Abstract Two major extreme-weather events occurred in New York State between 2011 and 2012. Each with the odds of a 100-year occurrence suggesting that such extreme events are the region’s “new normal.” City and state policy-makers, in response, are studying how to develop a network of robust, resilient critical infrastructure facilities. These studies, however, typically fail to address interdependencies among critical infrastructures and lack a quantitative tool to investigate the maximum resilience possessed by a given infrastructure facility in the face of climate-change-induced hazards. We propose a multi-stage stochastic mathematical program to maximize network resilience given: i ) random arrival of extreme events; ii ) the network’s inherent capacity to withstand and cope with the aftermath of exogenous shocks; iii ) pre-, during-, and post-event strategies available to enhance system operability; and iv ) budgeting and technological restrictions facing policy-makers. Our approach allows both qualitative and quantitative paradigms to interact. Our model thus clarifies how to allocate resources proactively and how the network’s absorptive, adaptive, and restorative capacities can be coordinated to enhance overall system resilience. Our findings suggest that an integrated planning approach combined with smart allocation of resources across a network’s main elements creates a greater degree of resilience while utilizing less costly resilience-enhancing strategies.
Transportation Research Record: Journal of the Transportation Research Board, 2016
Sustainable transport commonly considers either the interaction between built and natural environ... more Sustainable transport commonly considers either the interaction between built and natural environments or the interface between transportation and interdependent critical infrastructure. Although considering each of these key dimensions is a crucial task for achieving sustainable transport, the dimensions are infrequently considered together. When an integrated network design framework is proposed, two important issues are taken into account: (a) the aftermath of potential severe weather episodes on metropolitan-area infrastructure and (b) the existing interdependencies across transportation and fuel supply chain networks. Then the response of infrastructure in the face of flooding hazards is investigated. Framed within a multistage linear stochastic program, the proposed model seeks to find fueling station deployment that provides the transportation network with optimum random functionality when the network is stressed or under attack. A set of numerical experiments illustrates how changes to enhancement strategies at different stages of government affect the optimal investments in resilient design.
Transportation Research Part A: Policy and Practice, 2016
Transport Policy, 2015
ABSTRACT Public–private partnerships (P3s) are likely to impact entire transportation systems in ... more ABSTRACT Public–private partnerships (P3s) are likely to impact entire transportation systems in fundamental ways. However, few studies have examined the potential impact of P3s on large-scale transportation networks. These studies have focused on modeling rather than on policy analysis. The literature thus does not offer guidance for designing and administering P3s to improve transportation system performance while maintaining profitability. Using Fresno, California's transportation network as a laboratory, we consider the effects of alternative P3 tolling approaches on profit maximization and system performance optimization at full urban transportation network scale. Based on system modeling results, we offer the following recommendations for policy makers to design and promote successful P3s in urban settings: (i) to promote a profitable and a socially beneficial system, toll rates should be set examining both profit-maximizing and system-optimal rates; (ii) even though tolls (i.e., higher travel costs) on a few roads help reduce travel demand they may, counter-intuitively, lead to higher total travel cost for the overall transportation system because of users’ decision to travel longer distances to avoid tolls, especially when high toll rates are applied; (iii) lower limit(s) on tolls (in addition to upper limits) may be required to enforce system-optimal tolling and avoid undercutting by private owners; (iv) a variable tolling approach (i.e., temporally- and spatially-varying tolls) significantly reduces congestion and increases profits relative to flat tolls; and (v) public officials should provide a comprehensive plan regarding past, current, and future P3 projects along with a detailed system-wide impact analysis to promote a more sustainable transportation system.
Networks and Spatial Economics, 2015
Fundamental changes in road ownership and pricing have been viewed as possible remedies for the r... more Fundamental changes in road ownership and pricing have been viewed as possible remedies for the road usage and funding challenges in the transportation sector. To fill the gaps in our knowledge about the choice among different ownership structures, we develop a multi-level programming model that integrates system performance and profit maximization, game theory, and modified traffic assignment sub-models. Using this model, we provide a set of policy insights for policy makers. First, toll roads are interdependent in a complex manner since some pairs of roads are substitutes and others are complements, and because such cross effects can be reversed in different time periods and under different own and cross toll rates. Second, each toll road’s profit generally increases when more roads are tolled since roads commonly act as substitutes to each other. With such an insight, policy makers can ensure higher (and/or less risky) profits from toll roads and better deals with private operators of toll roads. Third, a mixture of private and public toll roads could generate significant profits while reducing transportation costs dramatically, thus contributing to sustainability. Finally, a comprehensive long-run transportation plan must investigate various road ownership schemes and examine their impacts on the profitability and the performance of the transportation system as a whole.
Sustainability, 2016
This paper offers a broad overview of road pricing from a social welfare perspective. I first exa... more This paper offers a broad overview of road pricing from a social welfare perspective. I first examine two common objectives of road pricing: congestion management and profit making. My goal is to provide a guideline explaining how to promote a social-welfare-enhancing road pricing scheme. To this end, we should: (i) consider and improve public transportation systems by providing more environment-friendly transport options; (ii) include tolling profits in our welfare analysis (as opposed to what economists suggest) since residents are the real owners of roads not users, and since some users are from outside the region and so might not be excluded from analysis; and (iii) search for a holistic approach that takes into account system-wide impacts, disutility to users who change their travel behavior (i.e., switch to public transportation, shift their travel, or do not travel at all), and the impacts on land use, employment, and residents.
Transportation Letters The International Journal of Transportation Research
Studies examining the social cost of driving usually ignore the opportunity cost of having roads ... more Studies examining the social cost of driving usually ignore the opportunity cost of having roads in place: the associated land rents. Especially for geographic regions where land is valuable, including the rent costs may even lead governments to close some roads. By using the London congestion charging zone case, a more general long-run social cost curve is calculated with the addition of the rents. Based on the optimal road usage concept, this study found that including the rents in the cost/ benefit analysis significantly affects the results and can increase the social cost by up to 200% and decrease the optimal road usage by 40%.
The Clean Development Mechanism (CDM) is a program under the Kyoto Protocol designed to help deve... more The Clean Development Mechanism (CDM) is a program under the Kyoto Protocol designed to help developing countries reduce their greenhouse gas (GHG) emissions. The program was originally adopted to reduce the cost of compliance for Annex I countries and, as a result, has failed to foster renewable, transportation-related, or small projects. The fundamental question is whether or not the CDM can incentivize sustainable development, especially in terms of GHG reductions, in the ever-growing transportation sector of the developing world. Among the various transportation projects, fuel switch and mode switch projects are the most common options in the CDM, mainly because travel activity, vehicle efficiency and occupancy, and infrastructure investments are too broad for a project-based approach. A sectoral approach or Nationally Appropriate Mitigation Actions (NAMAs) could provide a better fit for transportation policies; however, probably due to its more complex structure, no sectoral transportation option has been approved in the CDM. This paper reviews and critiques the CDM, and considers modifications to improve the program in these contexts.
The authors examine the effects of New York’s Labor Law 240, known as the Scaffold Law, on worker... more The authors examine the effects of New York’s Labor Law 240, known as the Scaffold Law, on worker safety. This law is important because it generates much litigation and significantly increases the cost of infrastructure projects in the state, especially through insurance. Supporters of the 19th century law argue that it enhances worker safety. Critics suggest that it creates moral hazard, or reduced investment in precaution, on the part of workers. The authors assemble the first-ever panel data set across states, time, and economic activities to empirically examine those competing claims. The authors' data set includes 3,382 observations from 2000 to 2010 across 42 states and a variety of commercial activities. Using standard panel data techniques such as year-fixed effects, state-fixed effects, and robust standard errors, the authors found that New York’s Scaffold Law increases both fatal and nonfatal construction accidents. This effect is significant in magnitude, and is consistent with the predictions of standard models of liability rules. The authors conclude their study by examining the effect of Labor Law 240 on insurance loss costs in the state, finding that it significantly increases the cost of infrastructure construction through higher insurance costs, which is also consistent with reduced worker safety. The authors' analysis questions the ongoing efficacy of the law.
ABSTRACT Almost all road infrastructure is treated as a public good and seen as a governmental ob... more ABSTRACT Almost all road infrastructure is treated as a public good and seen as a governmental obligation. But roads differ from other public goods such as national defense in both non-rivalry and nonexclusiveness features. Moreover, Financing construction and maintenance of road infrastructure is challenging because in most countries, government revenues for road construction and maintenance are insufficient. Here, the idea of road privatization is introduced as a possible alternative. Although there are many political and societal hindrances in implementing this idea, its potential to solve problems in transportation is indisputable. The road owner pays the government for the externalities produced from his property (pollutions or accidents) but can make money by charging users (passing the externalities burden to users, while easing congestion and free rider problems) and because the road is privately constructed and owned, the opportunity cost of the road construction and maintenance is better accounted for. By assigning the road’s property to private sectors, the supply side might become more efficient based on the transformation from a publicly subsidized market to an open market framework. The equity problem of the new pricing scheme can be partially solved with a rebate policy similar to creditbased congestion pricing (CBCP).
Renewable and Sustainable Energy Reviews, 2016
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Papers by Omid M. Rouhani