This document describes the implementation and evaluation of the existing Road Weather Information System Environmental Sensor Station Siting Guidelines (Guide) based on State Department of Transportation (DOT) needs and practices in the field environment. Recommendations for revisions and enhancements to the Guide are then derived from the evaluation.
The Guide was an outcome of many years of research and development in response to traveler and transportation department needs for better road weather information. In 2004 the FHWA, AASHTO SICOP, and the Aurora Pooled Fund Program decided to jointly sponsor the development of the Guide as a means of documenting common transportation industry practices in placing road weather stations and sensors in the field. As stated in the Guide, RWIS generally refers to the hardware, software, and communications elements needed to collect, transmit, process, disseminate, and display field observations. The ESSs are the field collection components of RWISs. The Guide, issued early in 2005, focuses primarily on the ESS, and offers a set of recommendations, not standards, for agencies and vendors to follow.
While the Guide is based on current practices, there is a need to evaluate its applications in the field, ensuring that the recommendations are implementable, understandable and useful. There are currently about 2,400 ESSs deployed by State DOTs and the District of Columbia. The deployment of many of these systems predates the Guide, and there are no apparent uniform bases for their deployment. As such, the value of the ESS investments and their use by the greater weather community may be limited by the diversity of deployments.
In addition, recent initiatives have created incentives to revisit and potentially enhance the Guide. For example, FHWA’s Road Weather Management Program has sponsored a variety of development efforts and task forces under the aegis of the
Clarus Initiative. The
Clarus System gathers, quality checks, and disseminates observations from RWISs, and will itself be enhanced by increased standardization among those systems. Numerous agencies are investing in maintenance decision support systems (MDSSs) that use observations from ESSs to monitor current roadway conditions and to initialize forecast models which predict future road conditions.
