A novel system design and implementation for realtime sensing and warning of roadway hazards round-the-clock

Though there exist ready-made DSRC/WiFi/3G/4G cellular systems for roadway communications, there are common defects in these systems for roadway safety oriented applications and the corresponding challenges remain unsolved for years, i.e., WiFi cannot work well in vehicular networks due to the high probability of packet loss caused by burst communications, which is a common phenomenon in roadway networks; 3G/4G cannot well support real-time communications due to the nature of their designs; DSRC lacks the support to roadway safety oriented applications with hard real-time and reliability requirements in the most recent study [1].

To solve the conflict between the capability limitations of existing systems and the ever-growing demands of roadway safety oriented communication applications, we propose a novel system design and implementation for realtime warnings of roadway hazards, e.g., physical hazards such as puddles, rocks, and pits on the road, and behavioral hazards such as lane changing, speeding, careless left-turn, etc. Specifically, our demo aims to provide hazard sensing and warnings to users close to a hazard on the road in a realtime and reliable manner.

In our extensive experimental study, the latency is well controlled within the hard realtime requirement (100ms) for roadway safety applications given by NHTSA, and the reliability is proved to be improved by two orders of magnitude compared with existing experimental results [1]. To our best knowledge, it is the first system for roadway safety applications that provides guaranteed highly reliable packet delivery ratio of 99% within the strict hard-realtime requirement 100ms under various scenarios, e.g., highways, city areas, rural areas, tunnels, bridges. Even in the worst case that burst warnings coming from multiple neighboring vehicles at the same time, the experimental results still show that the system is able to stably receive 99% warning messages within the hard realtime requirement 100ms. Our design can be widely applied for roadway safety applications and facilitate the current research in both hardware and software design and further provide an opportunity to consolidate the existing work on a practical and easy-configurable low-cost roadway safety oriented system.