Iowa DOT News Release

Green energy drives safer data collection methods for Iowa DOT

Posted on: February 25, 2009

AMES, Iowa – Feb. 25, 2009 – The traveling public may notice a new addition to the landscape along Interstate 35/80 in Des Moines near the N.W. Beaver Road overpass. Two new technologies are now working in unison to collect highway data necessary for Iowa Department of Transportation (DOT) decision makers. A wind turbine powering state-of-the-art laser sensors allows for safe, continuous data collection.

The data collection technology implemented on I-35/80 in September 2008, uses the AxelLight laser sensor, which allows the Iowa DOT to perform challenging traffic studies without cutting into the pavement or needing to cross or venture onto a hazardous roadway to install traffic sensors in the pavement. This is the country’s first permanent installation of this technology. The installation on I-35/80 uses two sensors with parallel beams six feet apart that allows traffic data collection and complex vehicle classification in up to four lanes.

Another national first for this data collection unit is the way it is powered. A 20-foot wind turbine was installed in mid-February with a rotor diameter of 46 inches to power the AxelLight laser sensor. Of the Iowa DOT’s 160 traditional, non-laser permanent highway data collection sites around the state, 158 are powered by solar panels. The remaining two use AC power sources. The new AxelLight laser site on I-35/80 was not conducive to solar power due to limited exposure to the sun’s rays.

The data collected at the Iowa DOT’s permanent sites and nearly 12,000 manual counts conducted each year are used to evaluate future roadway needs, conduct traffic studies, provide information to the public and decision makers, and many other applications.




Contact:  Karen Carroll at 515-239-1448 or



Iowa highway in the evening