In 2003, the Ohio Department of Transportation (ODOT) expanded its Roadway Weather Information System (RWIS) with the addition of 86 weather stations to the 72 already in operation. The 158 weather stations provide coverage of all 88 Ohio counties making it the largest deployment of RWIS in the U.S. Information from the weather stations is processed by a central server located in Columbus. The data is used by ODOT garages for treatment of roads during snow and ice conditions. ODOT also provides the weather data on a web-server (www.buckeyetraffic.org) where travelers can check road conditions prior to making trips.

The weather station expansion cost $3.699 million. Eighty-six weather stations have been installed with two more sites going operational in the following construction season. The deployment was contracted as a product purchase wherein the vendor was responsible for equipment installation. ODOT required that the weather stations be NTCIP-compliant and support wireless communication. The contract also includes a two-year service agreement (recurring costs over 2 years) for maintenance support 365 days a year, 24 hours a day, and seven days a week with penalties imposed for down sites. The project cost consists of four major categories as shown in the table below:

The $3.699 million included the purchase of a standard build weather station (deployed along highways), weather station located at county offices, training, and warranty. Optional sensors, communication methods, and power sources could be purchased at additional costs. The total project cost did not include the cost of the cellular phones (two per weather station) and the monthly cellular service; however, it did include the programming of the cellular phones. ODOT provided traffic maintenance/lane closure during installation.

The standard build weather station (also referred to as an environmental sensing station (ESS)) cost $49,980. This weather station is re-locatable and consists of atmospheric sensors, pavement sensors, power source, and communications. The atmospheric sensors measure air temperature, dew point, relative humidity, wind direction & speed, precipitation type & rate, and visibility. A total of four wireless, removable pavement sensors are installed to measure road condition and temperature, and detect traffic. The pavement sensors are housed in a plastic cylinder that is installed flush with the road surface and can be easily removed prior to road maintenance. Each weather station is solar-powered. Batteries have been added at some northern sites to supplement power for reduced sunlight. Data communications between the weather station and the central server is via cellular service with data transmissions every five minutes. The communication service cost $49.95 for unlimited usage per site, per month. A second phone is used for maintenance only and cost $12.95 per site per month. The monthly communication fees are not included in the project cost. Additional pavement sensors could be installed at a cost of $1,746 each.

The weather station located at county offices cost approximately $29,538. This weather station is also re-locatable, but only provides a subset of the standard build functions: supports full atmospheric measurements, utilizes radio frequency (RF)-to Ethernet communications, includes a bridge deck simulation device, but does not measure pavement conditions. Five such sites have been modified to add pavement sensors at the request of the local ODOT manager. This unplanned modification cost an additional $10,000 each, approximately.

ODOT began deploying weather stations in 1991. The 72 weather stations already in place are not NTCIP-compliant. The cost to convert the older weather stations to NTCIP is approximately $288,000 ($4,000 each). The cost is greater to convert these non-NTCIP stations to an open-architecture (non proprietary) NTCIP - $780,000.

Notes:
See also: http://www.dot.state.oh.us/news/2003/12-01-03.htm