Since Clarus was introduced in 2004, interest in and use of the system has increased substantially. By May 31, 2009, 33 state departments of transportation (DOT), three local DOTs, and three Canadian provinces were contributing their Road Weather Information System (RWIS) Environmental Sensor Station (ESS) data to the Clarus System. Many of these agencies that are shown in the map below and their road weather information providers monitor current road weather conditions via the Clarus System web site (http://www.clarus-system.com) and subscribe to Clarus System data in order to monitor field equipment, track approaching weather systems, and support operational decisions.