When that happens, the same types of incidents, like following too close, become something more. That's when aggressive driving crosses the line into road rage, Falb said. Simple things may upset some drivers, Ludwig said. Seeing people talk on cell phones especially when weather creates poor road conditions or encountering slow and cautious drivers along the road. Iowa ranks first in the nation for the number of people over age 85 with a driver's license and third for people over age 65, Ludwig said.
Senior drivers are apt to be as cautious as anyone which slows traffic flow.
And Ludwig added that traffic in the state also is often slowed in spring and fall by farm implements on the roadway. That upsets people. Closing Interstate 35 because of bad weather or an accident also provokes the ire of some drivers. Drivers have shown a desperate need to keep traveling by following the back roads, Ludwig said. With the expected completion of the Avenue of the Saints within the next couple of years, traffic is only expected to increase.