Wetter Stau: Examining Extreme Weather and Traffic Congestion in Germany.

Wenig Schnee - viel Chaos

Extreme weather events, such as blizzards or heavy rains, cause traffic congestion. A new article in the Journal of Advanced Transportation looks at the relationship in Germany. In "A study of the influence of severe environmental conditions on common traffic congestion features," Hubert Rehborn and Micha Koller use German traffic data to study the relationship on the Autobahn. 

On the basis of real traffic and environmental data measured on German freeways, we studied common features of traffic congestion under the influence of severe weather conditions. We have found that traffic features [J] and [S] defining traffic phases “wide moving jam” (J) and “synchronized flow” (S) in Kerner's three-phase theory are indeed common spatiotemporal traffic features. The quantitative parameters for both traffic phases [S] and [J] were investigated in a comparison of “ideal” weather conditions (good visibility and no precipitation) and severe weather situations (icy road, wind, precipitation, etc.). We showed spatiotemporal congested patterns in several space–time diagrams based on the Automatic Tracking of Moving Jams/Forecasting of Traffic Objects (ASDA/FOTO) model reconstruction for roadside detectors. A statistical study of traffic phase [J] parameters was presented, showing the average values and standard deviation of the quantities. Similarities and differences were analyzed, and some consequences for vehicular applications were discussed to cope with severe weather conditions.

The full article can be found here

Book of the Week: The World Beyond The Windshield


Anybody who has gone on a roadtrip has experienced changing landscapes and introductions of new locales through the lense of a windshield. The World Beyond The Windshield: Roads and Landscapes in the United States and Europe is a collection of scholarly papers that examine the relaitonship between roads and landscapes. It touches upon aesthetics, concepts of space, and the evolution of road networks. You can borrow our copy or read it online

Truck Emissions at Container Terminals

Port of Singapore

Freight and transportation are large producers of emissions and considered a good area to target for emissions reduction. How though? A new paper from Transportation Research Part E: Logistics and Transportation Review examines how queing optimization can help. "Reducing truck emissions at container terminals in a low carbon economy: Proposal of a queueing-based bi-objective model for optimizing truck arrival pattern," estimate emissions produced during truck idling and wait times at ports. 

This study proposes a methodology to optimize truck arrival patterns to reduce emissions from idling truck engines at marine container terminals. A bi-objective model is developed minimizing both truck waiting times and truck arrival pattern change. The truck waiting time is estimated via a queueing network. Based on the waiting time, truck idling emissions are estimated. The proposed methodology is evaluated with a case study, where truck arrival rates vary over time. We propose a Genetic Algorithm based heuristic to solve the resulting problem. Result shows that, a small shift of truck arrivals can significantly reduce truck emissions, especially at the gate.

You can read the full paper here


Special Semiar: Ricardo A. Daziano on "Accounting for Uncertainty in Willingness to Pay for Environmental Benefits"

(130/365) March 3, 2010: Who defines these terms?

Tomorrow, Thursday May 17, there will be a special seminar. Ricardo A. Daziano of Cornell University will present, "Accounting for Uncertainty in Willingness to Pay for Environmental Benefits."

Previous literature on the distribution of willingness to pay has focused on its heterogeneity distribution without addressing the interval estimation problem.  In this paper we derive and analyze Bayesian confidence sets for quantifying uncertainty in the determination of willingness to pay for carbon dioxide abatement. We use two empirical case studies: household decisions of energy-efficient heating versus insulation, and purchase decisions of ultra-low-emission vehicles. We first show that deriving credible sets using the posterior distribution of the willingness to pay is straightforward in the case of deterministic consumer heterogeneity. However, when using individual estimates, which is the case for the random parameters of the mixed logit model, it is complex to define the distribution of interest for the interval estimation problem. This latter problem is actually more involved than determining the moments of the heterogeneity distribution of the willingness to pay using frequentist econometrics. A solution that we propose is to derive and then summarize the distribution of the point estimates of the individual willingness to pay.

The seminar will be in 212 O'Brien Hall from 2-3 PM.

New Global BRT Database

Estação e vermelhão

This week BRTdata.org was launched by the Bus Rapid Transit Center of Excellence and EMBARQ. The site acts a clearinghouse for data from BRT systems all over the world. You can see performance indicators by country or city, such as passengers per day, number of corridors, and legth. Check it out and let them know what you think.

Friday Seminar: Shomik Mehndiratta on Sustainable Low-Carbon City Development in China

Shanghai Urban development centre on people's square

This week's TRANSOC Friday Seminar, which is happening today (4/6), features Shomik Mehndiratta from the World Bank. He will present, "Sustainable Low-Carbon City Development in China."

This talk summarizes the key messages of a recently released book that examines, through the specific lens of low-carbon development, the lessons of the World Bank’s activities related to urban development in China.  Amid unprecedented levels of urban migration, rapidly increasing incomes, double digit annual growth in motorization and expanding city forms, many Chinese cities are already on a high carbon-emission growth path. With China set to add an estimated 350 million residents to its cities over the next 20 years, the case for urgent action is strong.

On one hand, China's cities are already reacting to ambitious commitments their leaders have made to reduce the carbon and energy intensity of the economy and transition to a low-carbon growth path.  The country's current (12th) Five-Year Plan includes, for the first time ever, an explicit target to reduce carbon intensity by 17 percent by the end of 2015. However, the imperative to reduce carbon intensity is only one of many competing priorities for government officials in the midst of unprecedented urbanization, modernization, and economic development.

What are the choices Chinese cities are making?  And what are the implications?  Achievements and challenges to low-carbon city development in China will be discussed with a particular focus on transport, land-use and urban spatial development.

The seminar will be at 4:00pm in 534 Davis Hall as usual. Don't miss Cookie Hour in the library at 3:30!

Friday Seminar - Anthony Evans on Simulating Airline Operational Responses to Environmental Constraints


This week’s Friday TRANSOC Seminar has Anthony Evans, Postdoctoral Fellow, NASA Ames Research Center, presenting “Airline Operational Responses to Environmental Constraints.”

Significant growth is anticipated in global air transportation over the coming decades, which is expected to have local and global environmental impacts. This presentation describes a model that predicts airline flight network, frequency and fleet changes in response to policy measures that aim to reduce the environmental impact of aviation. Such airline operational responses to policy measures are not considered by most integrated aviation-environment modelling tools. By not modelling these effects the capability of the air transport system to adjust under changing conditions is neglected, resulting in the forecasting of potentially misleading system and local responses to constraints.


Friday Seminar - Jeff Lidicker on Pavement Resurfacing Policy for Minimization of Life-cycle Costs and Greenhouse Gas Emissions

Pot hole and dent - #71/365

Tomorrow's TRANSOC Friday Semiar has Ph.D. candidate Jeff Lidicker presenting, "Pavement Resurfacing Policy for Minimization of Life-cycle Costs and Greenhouse Gas Emissions."

In recent decades pavement management optimization has been designed with the objective of minimizing user and agency costs.  However, recent analyses indicate that pavement management decisions also have significant impacts on life-cycle GHG emissions.  This study endeavors to expand beyond minimization of life-cycle costs, to also include GHG emissions.  We extend previous work on the single-facility, continuous-state, continuous-time optimal pavement resurfacing problem, to solve the multi-criteria optimization problem with the two objectives of minimizing costs and GHG emissions. Results indicate that there is a tradeoff between costs and emissions when developing a pavement resurfacing policy, providing a range of GHG emissions reduction cost-effectiveness options.  Case studies for an arterial and a major highway are presented to highlight the contrast between policy decisions for various pavement and vehicle technologies.

The seminar will take place on December 9 at 4:00 PM in 212 O'Brien Hall. (That's a new location!) There won't be a Cookie Hour this week as well. We'll see you in the new year!

Friday Seminar: Mazyar Zeinali on Commercial Aviation and Climate Change

Airbus A380-800

This week's TRANSOC Friday Seminar is Mazyar Zeinali from the International Council on Clean Transportation presenting "Commercial Aviation and Climate Change: The Role of Technology."

The environmental impact of aviation has been of concern for several decades including specific concerns such as local air quality, impacts on Earth's protective ozone layer, and aircraft induced cloudiness. However, with the 1999 seminal publication by the Intergovernmental Panel on Climate Change (IPCC) entitled 'Aviation and the Global Atmosphere', significant concern has arisen both in aviation climate change impact and mitigation possibilities. To quantify expected return from future technology implementation (near to mid term), the International Civil Aviation Organizational (ICAO) commissioned and published a study conducted by a panel of independent experts (IEs). The IE technology scenarios included returns under typical/continuation of current business-as-usual practices and also accelerated implementation under added future regulatory pressure. The ICCT was a contributing organization to this ICAO study and Dr. Zeinali will present his findings and interpretations for specific technological packages envisioned by the panel and efficiency gains from implementing technology in tighter aircraft designs, better matching operational norms and patterns.

The seminar will take place October 7 from 4-5 PM in 406 Davis Hall. Cookie Hour will be at 3:30, as usual, in the library. 

Friday Seminar - David Brownstone on Fuel Economy Standards

green driving

Tomorrow's TRANSOC Friday Seminar is with David Brownstone of UC Irvine's Department of Economics. He'll present, "Consumer Response to Stricter Fuel Economy Standards."

The impacts of recent changes in Federal light-vehicle fuel economy standards depend crucially on consumers’ response to new vehicles with higher fuel economy and higher prices. Previous studies have primarily relied on stated preference experiments since there was little independent variation in vehicle price, fuel economy, and performance.  The recent introduction of hybrid-electric vehicles has provided some independent variation in these key vehicle attributes, so we use data from the 2009 NHTS data to estimate willingness to pay for light vehicle fuel economy.  We also estimate the “rebound effect” of purchasing more fuel efficient vehicles.  Finally we will comment on the impact of measurement errors and partial observability on previous studies.

The seminar will take place Friday, September 16, 2011 from 4-5 PM in 406 Davis Hall. Don't forget about Cookie Hour preceding it in the library at 3:30 PM. See you there!


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