Grants and Contributions:

Grant or Award spanning more than one fiscal year. (2017-2018 to 2022-2023)

The highway system provides the most important mode of transportation for passengers and goods. Planning and design of the road infrastructure was a relatively simple task until the introduction of motorized vehicles in early 1900s, which required major changes in road design and construction. However, the development of road design guidelines to address arising safety problems was around half a century behind the actual need and was even later in Canada. Recent advancements of communication and computing technologies have put vehicle design on the path of significant revolutionary changes through the development and deployment of two separate new vehicle technologies: connected vehicles (CVs), where vehicles can communicate with each other and with the highway infrastructure, and autonomous vehicles (AVs) which are also known as self-driving vehicles. While some CV/AV technologies are already deployed on the road, estimates put wide-scale implementation as early as 2020-2025. Significant benefits including reduced congestion, reduced fuel consumption and vehicle emissions, improved mobility, and considerable reduction of collisions are expected not only with the full implementation of these technologies but also as they penetrate the market. Although CV/AV technologies are developed to operate on the existing road infrastructure, road modifications will certainly be required to realize the full benefits of these new technologies.
This research proposal aims at investigating challenges that may arise as the vehicle fleet transitions from current technology to CV/AV and can negatively affect traffic safety. Specifically, the proposal has two objectives in relation to the interaction between a vehicle fleet with different technology levels and the geometric design of arterials and freeways. The first objective is to minimize speed disparity between individual vehicles in the mixed fleet on a specific highway element or from one element to the other. Such disparity is known to negatively impact traffic safety, and has been a criterion of highway design consistency evaluation. The second objective is to overcome challenges of vehicles entering or exiting freeways due to the ability of AVs to travel in platoons with minimal gaps and to optimize traffic mobility and safety at freeway ramp terminals. To achieve these objectives, the proposal expands design consistency and reliability analysis to highway design in a CV/AV environment including the transition period. Successful undertaking of the proposed research will help provincial ministries of transportation prepare for the new vehicle technologies and avoid significant problems that can undermine the benefits of CV/AVs. The models can also assist vehicle manufacturers develop real-time protocols for speed and gap management based on vehicle-to-vehicle communication.