Maryland State Highway Administration estimated fog warning system addition to existing weather stations near Big Savage Mountain, Maryland cost $75,000.
Keyers Ridge, Maryland, United States
Big Savage, Maryland, United States
Friendsville, Maryland, United States
In 2003, the Maryland State Highway Administration (SHA) developed a plan to install an automated fog-warning system in fog prone areas of I-68 near Big Savage Mountain. The warning system was designed to use existing weather stations, visibility sensors, and wireless communications equipment to activate flashers on roadside message signs during periods of limited visibility. Each sign had two flashing lights and a printed message displaying the text REDUCED VISIBILITY WHEN FLASHING.
This report provided a cost estimate to add fog warning systems to the existing ESS at Big Savage and Keysers Ridge, and one proposed ESS at Friendsville. Each warning system interfaced spread-spectrum wireless communications with an ESS contact enclosure. When fog was detected, the contact enclosure triggered a transmitter and activated the warning signs. The ESS sensor data, including surface, subsurface, and atmospheric data were sent to the central Road Weather Information System (RWIS) at the District-6 operations center via a telephone landline.
ESS site selection was dependent on the availability of utilities (telephone and power) in the area, the ability to collect representative data, and the need to install line-of-sight wireless communications between ESS transmitters and the roadside warning signs. In areas where line-of-sight wireless communications were limited, signal repeaters were proposed.
The table below, excerpted from the report, provides a cost estimate to add a fog warning system to a previously installed ESS at Big Savage.
|
The table below, excerpted from the report, provides a cost estimate to add a fog warning system to a previously installed ESS at Keysers Ridge.
| Quantity | Description | Unit Cost | Extension |
|---|---|---|---|
| LS | Modify existing ESS (RWIS station) to provide contact closure under low visibility conditions | $2,500 | $2,500 |
| 1 | Furnish and install radio transmitter, cabinet, and omni-directional antenna | $5,000 | $5,000 |
| 3 | Furnish and install solar panel power system (three warning signs) | $7,500 | $22,500 |
| 3 | Furnish and install warning sign with LED’s and flasher and radio receiver with Yagi directional antennas | $13,000 | $39,000 |
| LS | Contingency |  | $6,000 |
| TOTAL | | | $75,000 |
The table below, excerpted from the report, provided an estimate of the cost to install a new ESS (RWIS station) and fog warning system at Friendsville.
| Quantity | Description | Unit Cost | Extension |
|---|---|---|---|
| LS | Furnish and install new ESS (RWIS station) that provides contact closure under low visibility conditions | $60,000 | $60,000 |
| 1 | Furnish and install radio transmitter, cabinet, and omni-directional antenna | $5,000 | $5,000 |
| 2 | Furnish and install solar panel power system (two warning signs) | $7,500 | $15,000 |
| 2 | Furnish and install warning sign with LED’s, flasher, and radio receiver with Yagi directional antenna. | $13,000 | $26,000 |
| LS | Electrical power and telephone connect | | $5,000 |
| LS | Contingency | | $14,000 |
| TOTAL | | | $125,000 |
Note: An ESS is also referred to as a road weather information system (RWIS) station, or a weather station.
LS = Lump Sum
Notes:
Click here for image of a weather station near Big Savage.
Click here for image of a fog warning sign.
I-68 Fog Detection System Planning Report
Cost to modify Big Savage and Keyser sites: $75,000 per location. Cost of new infrastructure at Friendsville: $125,000.
