(This article is reproduced with permission from the Center for Transportation Research and Education at Iowa State University. The article and accompanying photographs appeared in the February-March 1998 issue of "Technology News.")

Preventing deer from crossing the road at night and colliding with cars could save millions of dollars in property damage. The Iowa Department of Transportation (Iowa DOT) is testing a reflector system that may do just that.

In 1996 the Iowa DOT set up demonstration project areas in one-mile sections along the following roadways:

• Iowa 9 east of Decorah
• U.S. 34 near Viking Lake State Park
• Iowa 1 Near Lake Darling State Park
• Iowa 175 east of Eldor
• Iowa 14 north of Parkersburg

The special reflectors, made in Austria, are mounted on posts 24 inches higher than the top of the pavement. They reflect light from headlights, forming a light fence that's only visible from beyond the roadway.

FIGURE 1
The special reflectors are manufactured in Australia
Photos courtesy of the Iowa DOT.

Drivers cannot see the fence.

The spacing of the reflectors along the side of the road is equal to their spacing across the road. Narrower roads require more reflectors.

FIGURE 2
Spacing of the reflectors is determined by the width of the road
Photos courtesy of the Iowa DOT.

The reflectors cost about $17 each. The cost of the posts depends on the type used. The Iowa DOT used tube-in-tube posts that cost $10-12 each.

Per mile the whole reflector system cost between $8,000 and $10,000 up front, according to Tim Crouch, an Iowa DOT traffic engineer. That does not include continuing maintenance costs for keeping posts aligned and reflectors cleaned twice a year.

After the three-year review period is up, Crouch will have a clear idea about the cost effectiveness of the whole system compared to the cost of cleaning up carcasses and estimated property damage. In 1996 8,279 reported deer-car accidents in Iowa resulted in several million dollars of property damage. Such accidents are rarely fatal for people but often fatal for deer.

So far it's hard to tell if the reflectors are actually reducing accidents, Crouch says. But maintenance people he's talked to have the impression that fewer deer are being killed in the test sections.

The Washington state department of transportation conducted a four-year study of a similar reflector system in the early 1980s. The reflectors were alternately covered and uncovered at regular intervals. During periods when the reflectors were covered, 52 deer were killed at night, compared to six killed when the reflectors were uncovered and operational.

Crouch believes the reflector system will be feasible for counties.

For more information about the Iowa DOT project, contact Crouch, 515-239-1545.

Editor' Note: For more information on wildlife reflectors and wildlife-vehicle collisions, click through to these past articles from the "Road Management and Engineering Journal" at this website.

Deer-Wildlife Collisions Are Numerous and Costly. Do Countermeasures Work?

Roadside Wildlife Reflectors -- Do They Work?

Swareflex Wildlife Warning Reflectors: One Preventive Measure for Wildlife- Vehicle Collisions

Study Shows Problem of Vehicle-Wildlife Collisions Increasing