Clear Roads Ahead for Wisconsin Counties
Using data from pavement and weather sensors throughout the State, county highway agencies in Wisconsin determine the best strategies for keeping roads open during winter storms.
The Challenge
Winter in Wisconsin brings a range of severe weather—snowfalls as deep as 3,800 mm (150 in), freezing rain, and days when the temperature never breaks -18 ºC (0 ºF). This weather can be tough on drivers, and it's even tougher on the State's county highway agencies, which are responsible for keeping State, local, and Interstate highways passable.
To the Wisconsin Department of Transportation (DOT) and the county highway agencies with which it contracts for snow removal, winter storms pose a maintenance challenge. To give county maintenance managers the information they need to plan their response to storms, the Wisconsin DOT decided to adopt a road weather information system (RWIS), a technology evaluated under the Strategic Highway Research Program (SHRP).
Putting the Technology to the Test
In 1985, Wisconsin DOT became one of the first State highway agencies to install an RWIS. The first RWIS station was installed on the Hoan Bridge over Milwaukee Harbor on Lake Michigan. The site is very humid, and precipitation, wind, and temperature can change rapidly. The rapidly changing conditions made it almost impossible for the DOT to determine at any one time whether the bridge deck had iced over. The new RWIS station changed all that.
With 51 RWIS units currently in place, Wisconsin now has "one in every corner of the State," says Michael Adams, an employee of Matrix Management Group, who manages Wisconsin DOT's RWIS program. The pavement and weather sensors are located at trouble spots like the Hoan Bridge and at sites with weather conditions representative of larger areas.
It's not enough to collect the data—the State DOT must make it accessible to county maintenance managers. Currently, portable computers are used to retrieve RWIS data. County maintenance managers must dial into the system. But Wisconsin DOT is implementing satellite delivery so that a constant stream of information will flow to county maintenance garages. This will ensure that maintenance managers always have the latest information on road and weather conditions.
The extensive RWIS network allows county maintenance managers anywhere in Wisconsin to get data on pavement and weather conditions in their own area and on weather systems moving their way. "While someday it may be helpful to have more weather sensors," Adams says, "we now have enough to put together a very good forecast."
Adams' background as a meteorologist contributes to the system's success. He oversees all aspects of the system, from planning to weather forecasting to training. Wisconsin was the first State to hire a consulting meteorologist to manage its RWIS on a full-time basis.
Wisconsin DOT is exploring options for making the system even more useful while keeping costs under control. To cut costs—and possibly improve reliability—the DOT is studying new methods of retrieving data from the RWIS units.
The DOT is encouraging the use of RWIS data in anti-icing strategies, which involve the application of deicing chemicals before a storm to prevent snow and ice from bonding to the pavement. Several counties are now adopting anti-icing procedures.
The Benefits
By implementing an RWIS, Wisconsin DOT has given county highway agencies the tools to develop effective winter maintenance strategies. The results are:
- Clearer, safer roads.
- More efficient use of deicing materials.
- Increased awareness of anti-icing strategies among county highway agencies.
- Lower costs for winter maintenance.
