CAREER: Dynamic State Transitions in Vehicular Traffic and the Effects of Driver Behavior

这项教师早期职业发展（Career）计划的目标是调查驾驶员行为，如跟随汽车和变道，对交通状态转换（即交通状况的变化，如速度）的影响。本研究主要关注高速公路阻塞点（即瓶颈）附近的过渡、合并和队列末端（车辆遇到拥堵的地方）。这些区域周围的过渡可能导致无序的交通状况，如走走停停的驾驶，由于速度的急剧变化和频繁的变道机动。本研究包括四个主要任务：(i)收集新的单个车辆数据；（ii）分析交通转换的一般特征（如交通流量、密度和速度的变化）；（iii）分析驾驶员行为并将其与一般特征联系起来；（iv）扩展/开发能够再现观察到的转换现象的驾驶员行为模型。如果成功，这项研究将揭示转变的物理机制；也就是说，个体驾驶员的行为（例如，跟随车辆、变道）如何在时间和空间上控制流量、密度和速度的变化。了解这些机制对机动性和安全性具有重要意义。高速公路瓶颈周围的转换可以决定瓶颈吞吐量，从而决定高速公路网络的延迟。此外，由于速度的突然变化和频繁的变道操作，过渡区域的车辆更容易发生碰撞。因此，本研究的结果将有可能推进交通控制策略，以更有效地管理拥堵并提高安全性。教育和推广活动包括开发一个项目网站、一个收集探测数据的智能手机应用程序、用于实际学习数据分析方法和建模的基于网络的模块。通过这些手段，该项目将吸引本科生和研究生、STEM（科学、技术、工程和数学）高中教师长期接触高中生、其他学科的研究人员和行业利益相关者。

The objective of this Faculty Early Career Development (CAREER) program award is to investigate the effects of driver behaviors, such as car-following and lane-changing, on traffic state transitions (i.e., changes in traffic conditions such as speed). This research focuses on transitions near freeway choke points (i.e., bottlenecks), merges, and ends of queues (where vehicles encounter congestion). Transitions around these regions can lead to disorderly traffic conditions, such as stop-and-go driving, due to sharp changes in speed and frequent lane-changing maneuvers. This research consists of four primary tasks of (i) collecting new individual vehicle data, (ii) analyzing general features (e.g. changes in traffic flow, density, and speed) of traffic transitions, (iii) analyzing driver behaviors and linking them to the general features, and (iv) extending/developing models of driver behaviors capable of reproducing the observed transition phenomena.If successful, this research will uncover the physical mechanisms of transitions; i.e., how individual driver behaviors (e.g., car-following, lane-changing) govern changes in flow, density, and speed in time and space. Understanding these mechanisms has important implications for mobility and safety. Transitions around freeway bottlenecks can determine bottleneck throughput and hence the delays on freeway networks. Further, vehicles in transition regions are more prone to crashes due to sudden changes in speed and frequent lane-changing maneuvers. Therefore, the results from this research will potentially advance traffic control strategies to manage congestion more effectively and improve safety. Educational and outreach activities involve the development of a project website, a smart-phone application to collect probe data, web-based modules for hands-on learning of data analysis methods and modeling. Using these means, this project will engage undergraduate and graduate students, STEM (science, technology, engineering, and mathematics) high school teachers to reach out to high-school students in the long term, researchers in other disciplines, and industry stakeholders.