2013 Session: 804

• Investigation of Lane Flow Distribution on Hard Shoulder Running Freeways
  Abstract: Responding to an impending demand growth at an existing reactive managed lane system, and in order to provide a timely and more effective temporary hard shoulder activation, short-term prediction models are developed. A lane-oriented attribute, namely the left lane flow distribution ratio (LLFDR), is introduced, aiming to ameliorate the system by capturing the forthcoming stream dynamics and reconfiguring it to proactive. To assess the impact of its implementation to the network's performance, an exploratory analysis was effectuated based on data acquired by seven radar sensors located every 500 m, along a Swiss freeway section that is not affected from incoming or exiting traffic. A locally weighted regression is employed to provide a more accurate insight of the traffic behaviour, comparing observations derived during the regular operation of the system and a period that it was suspended, with respect to seasonality patterns. To describe the impending stream motion by examining different time-volume clusters (off-peak and rush-hour), two prediction models were specified according to the time range. The preliminary results of the study for several prediction horizons, demonstrate an acceptable prediction uncertainty. The hard shoulder activation prediction confirms the analysis of the operation impact findings of this research.
  Authors: Samoili, Sofia; Efthymiou, Dimitrios; Antoniou, Constantinos; Dumont, Andre-Gilles
  Authors: Samoili, Sofia; Efthymiou, Dimitrios; Antoniou, Constantinos; Dumont, Andre-Gilles
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 804
  Paper Number: 13-0964
  Practice-Ready: Yes
• Operational Performance of High-Occupancy-Vehicle Facilities: Comparison of Contiguous and Limited Access HOV Lanes in California
  Abstract: Traffic operational data from High-Occupancy Vehicle (HOV) facilities in California are evaluated in this study. Freeway performance measures are tailored to gauge efficiency and effectiveness of HOV operations and applied to measure the operational performance of HOV facilities in the study sites. The measured operational performance is then compared between HOV and GP lanes and between different types of HOV configurations. Findings from the comparative evaluation show that when compared with GP-lane travels, HOV facilities carry more people-miles with fewer vehicle-miles while offering substantial travel time savings to their users; and, when compared with limited-access, contiguous-access offer greater travel time savings for the sites examined in this study while the levels of utilization by vehicles and people are similar. Statistical tests validate the statistical significance of differences of operational performance. Based on these findings, implications for further improvement of HOV facilities are discussed.
  Authors: Jang, Kitae; Chan, Ching-Yao; Du, Yao-Qiong
  Authors: Jang, Kitae; Chan, Ching-Yao; Du, Yao-Qiong
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management
  Session: 804
  Paper Number: 13-4039
  Practice-Ready: Yes
• Investigation of Lane Flow Distribution on Hard Shoulder Running Freeways
  Authors: Samoili, Sofia
  Authors: Samoili, Sofia
  Year: 2013
  Document Type: Presentation
  Subject: Operations and Traffic Management
  Session: 804
  Paper Number: 13-0964
• Operational Performance of High-Occupancy-Vehicle Facilities: Comparison of Contiguous and Limited Access HOV Lanes in California
  Authors: Jang, Kitae
  Authors: Jang, Kitae
  Year: 2013
  Document Type: Presentation
  Subject: Operations and Traffic Management
  Session: 804
  Paper Number: 13-4039
• Demand Shifts and Observed Effects on Traffic Operation as a Result of Congestion Pricing Implementation on San Francisco Bay Bridge
  Authors: Du, Yaoqiong
  Authors: Du, Yaoqiong
  Year: 2013
  Document Type: Presentation
  Subject: Operations and Traffic Management
  Session: 804
  Paper Number: P13-6209