2013 Session: 313

• Incorporating Weather Effects in Highway Capacity Manual Reliability Analysis
  Abstract: This study details a methodology for incorporating weather effects in an HCM-based Freeway Reliability analysis. The methodology is capable of estimating historical weather probabilities as well as predicting future year weather probabilities by weather condition from a 10 year historical average probability database. Probabilities for historical analyses are directly calculated from detailed hourly weather reports for the period of time that freeway reliability is reported. The methodology is applied for the 101 largest metropolitan areas in the US to create a probability database for use in a probabilistic scenario generator to incorporate non-recurring effects in HCM freeway operations analysis.In addition to presenting the methodology, sample results are validated at four locations. Probabilities of each weather type are shown with a confidence interval based on the variability of probabilities by year within the 10 year sample. Finally, prediction errors are calculated with multiple sample sizes. The results show that prediction errors stabilize near the 10 year sample size.
  Authors: Chase, R. Thomas; Hajbabaie, Ali; Schroeder, Bastian J.
  Authors: Chase, R. Thomas; Hajbabaie, Ali; Schroeder, Bastian J.
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Operations and Traffic Management
  Session: 313
  Paper Number: 13-0227
• Quantification of Weather Influences on Freeway Bottlenecks
  Abstract: Weather is a major source of non-recurring delay on freeways within the United States. How weather affects areas of daily recurring delay, particularly freeway bottlenecks, has not been thoroughly researched. A type of freeway bottleneck in the form of a lane drop was studied across two winters at a site of daily recurring congestion. This bottleneck was located in Pittsburg, California. Queue discharge flow was compared between rainy days and clear days either one week before or after the rainy event. Discharge flows during rainy events dropped by an average of 11% and this difference was significant to the 95% confidence level. Conclusions could not be made on volume changes to individual lanes during rainy events. With future examination of other bottleneck locations and types, analysts will be able to better predict trip times and agencies will gain knowledge for prioritizing operational improvements.
  Authors: Seeherman, Joshua Lawrence; Skabardonis, Alexander
  Authors: Seeherman, Joshua Lawrence; Skabardonis, Alexander
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Operations and Traffic Management
  Session: 313
  Paper Number: 13-4355
• Approaches and Gaps in Weather-Responsive Traffic Management: U.S. and European Perspectives
  Abstract: Traffic management and operations during adverse weather is a major challenge for transportation agencies around the world. Weather is a common cause of crashes and delays on the highways everywhere, accounting for large number of fatalities and hours of delay every year in the US and Europe. Significant improvements have been made in the development and implementation of weather-responsive traffic management strategies to alleviate the impacts of weather, both in the US and Europe. These include weather and traffic data collection and integration, traffic analysis and modeling, human factors analysis and performance evaluation. This paper will describe the state-of-the practice in weather-responsive traffic management in the US and Europe including the types of strategies, systems and tools being used, their similarities, and their effectiveness in traffic operations. The paper will also describe the relevant research activities being undertaken in both countries and how they can coordinate and benefit from each other’s efforts. Finally, the gaps in current practices and research related to weather-responsive traffic management are identified, and recommendations on how these gaps can be filled are described
  Authors: Alfelor, Roemer; Billot, Romain; El Faouzi, Nour-Eddin; Pisano, Paul A.
  Authors: Alfelor, Roemer; Billot, Romain; El Faouzi, Nour-Eddin; Pisano, Paul A.
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Operations and Traffic Management
  Session: 313
  Paper Number: 13-1499
  Practice-Ready: Yes
• Impact of Inclement Weather on Hourly Traffic Volumes in Buffalo, New York
  Abstract: Inclement weather conditions (such as rain, snow, fog and ice) can create hazardous driving circumstances, which affect the performance of transportation networks. This study analyzes how inclement weather affects hourly traffic volumes on freeways in Buffalo, New York by examining the impact of weather factors such as visibility, temperature, weather type, precipitation and wind speed. To do so, weather and traffic data was collected and modified to form a base case and an inclement weather case. By comparing the base case and inclement weather case several discoveries were made, including when the greatest volume reduction will occur and which weather factors affect the traffic volume. The modified volume and traffic data was also used to find a regression model that can predict traffic volume based on weather factors. The study shows that volumes for times during which inclement weather occurred were significantly lower than dry weather volumes, and that the difference was greatest during peak hours (7:00 AM to 9:00 AM, and 3:00 PM to 5:00 PM), with the volume reductions ranging from 13.3 to 33.9 percent. The study also demonstrated that among the different weather indicators considered, weather type and cumulative precipitation appear to be the most significant predictors of percent volume reductions.Key Words: Inclement weather impact, snow impact, traffic volume, regression analysis
  Authors: Bartlett, Andrew; Lao, Winnifred; Zhao, Yunjie; Sadek, Adel W.
  Authors: Bartlett, Andrew; Lao, Winnifred; Zhao, Yunjie; Sadek, Adel W.
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Operations and Traffic Management
  Session: 313
  Paper Number: 13-3240
  Practice-Ready: Yes
• Incorporating Weather Effects in Highway Capacity Manual Reliability Analysis
  Authors: Chase, R.
  Authors: Chase, R.
  Year: 2013
  Document Type: Presentation
  Subject: Maintenance and Preservation; Operations and Traffic Management
  Session: 313
  Paper Number: 13-0227
• Approaches and Gaps in Weather-Responsive Traffic Management: U.S. and European Perspectives
  Authors: Billot, Romain
  Authors: Billot, Romain
  Year: 2013
  Document Type: Presentation
  Subject: Maintenance and Preservation; Operations and Traffic Management
  Session: 313
  Paper Number: 13-1499
• Impact of Inclement Weather on Hourly Traffic Volumes in Buffalo, New York
  Authors: Bartlett, Andrew
  Authors: Bartlett, Andrew
  Year: 2013
  Document Type: Presentation
  Subject: Maintenance and Preservation; Operations and Traffic Management
  Session: 313
  Paper Number: 13-3240
• Impact of Inclement Weather on Hourly Traffic Volumes in Buffalo, New York
  Authors: Sadek, Adel
  Authors: Sadek, Adel
  Year: 2013
  Document Type: Presentation
  Subject: Maintenance and Preservation; Operations and Traffic Management
  Session: 313
  Paper Number: 13-3240
• Quantification of Weather Influences on Freeway Bottlenecks
  Authors: Seeherman, Joshua
  Authors: Seeherman, Joshua
  Year: 2013
  Document Type: Presentation
  Subject: Maintenance and Preservation; Operations and Traffic Management
  Session: 313
  Paper Number: 13-4355