Research Papers

Implementation of Road Condition Warning System (RCWS) in Alberta as a mitigation measure to improve safety at highway locations impacted by extreme weather conditions.

Version 1
Date added June 27, 2017
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Category 2017 CARSP XXVII Toronto
Tags Policy and Practice, Session 5C
Author/Auteur Allan Lo
Stream/Volet Policy and Practice

Slidedeck Only Presentation (no paper submitted)



In Alberta, severe weather conditions particularly during the winter season have a significant impact on traffic operations and safety of the provincial highway network. There are "hot spot"-locations within the network that have developed distinct collision patterns resulting from these extreme weather conditions. One such location is Highway 22 west of Fort MacLoad where severe westerly cross-winds often reaching 160 km/h have resulted in numerous run-of-road vehicle collisions (trucks in particular). Other "hot spot" locations include two bridge sites where frequent fog and preferential icing conditions in winter create a risk of vehicle skidding often leading to a collision (e.g. a pattern of collisions with the barrier). Deteriorating collision history at these three locations necessitated immediate actions through the implementation of an Intelligent Transportation System (ITS) solution called Road Condition Warning System (RCWS). Alberta Transportation (AT) has implemented the RCWS at three "hot spot" highway locations to provide continuous monitoring and detection of severe weather and road conditions (e.g., high winds, fog and ice, etc.) and to provide timely, advance warning to the travelling public through the use of Dynamic Message Signs (DMS) and traditional control devices. The goal is to improve safety by reducing the number and severity of vehicle collisions at these locations and improved operations. A reduction in the societal costs resulting from the reduced vehicle collisions is another measurable benefit. Commercial trucks and the general public using the "hot spot" locations are the main groups benefiting from the RCWS initiative. Weather event information is also disseminated in real-time to AT operations staff through the RCWS alerting system and to the public through the Alberta Traveler Information System, 511Alberta. The RCWS was implemented between 2012-16 on the basis of the existing provincial Road Weather Information System (RWIS). The RCWS uses a designated local Environmental Sensing Station (ESS) which is part of the RWIS and the communications hardware to enable remote monitoring of the site's specific environmental conditions (e.g., high wind or preferential icing), in order to trigger pre-defined warning messages via local static signs with flashing beacons or DMS. The signs are strategically placed on the approaches to "hot spots" to give the travellers sufficient time to adjust their driving or to avoid the route altogether. The RCWS concept of operations and functional requirements were developed jointly by the AT team, consultant (IBI Group) and RWIS Service Provider (Schneider Electric) who installed and presently operates the system. Since the RCWS implementation, traffic operations at these "hot spot" have improved and there is also expectation that safety will improve overtime (a preliminary safety assessment is encouraging). The project team learned that the system implementation is an iterative process requiring extensive testing so additional time and funding provisions have to be added to the project. The concept of operations has to be defined early in the project based on the local knowledge with the participation of all stakeholders. The RCWS is the first system of this kind implemented in Alberta and could potentially be expanded to other "hot spot" locations.

Allan Lo