Turbo roundabouts: A brief safety, efficiency and geometry design review

Abstract

The application popularity of various roundabout types around the world has driven substantial efforts to optimize their geometry design. Implementing effective roundabouts requires optimizing traffic safety (TS) and traffic (operational) efficiency (TE) while considering various geometry and other factors. In multi-lane roundabouts driver indecision and misunderstanding of the driving rules and situations can lead to weaving conflicts and accidents. These accidents are frequent and often affect TS and TE. The turbo roundabout concept has emerged as a possible alternative to conventional multi-lane roundabouts, aiming to improve exclusively TS. However, some studies do not allow definitive conclusions about their TE (capacity) influence. To capture a relationship between turbo roundabout design, TS and TE parameters brief overview of the latest guidelines and studies is presented here.