On October 10, 2019, Iowa’s Innovation, Business and Law Center hosted Professor Cara Hamann, PhD, MPH, for a presentation on how public health researchers can impact road safety policy. Professor Hamann is a Clinical Assistant Professor in Epidemiology at the University of Iowa College of Public Health and Assistant Director for Training and Education for Iowa’s Injury Prevention Research Center. Her work is focused on high-risk and vulnerable road users, including bicyclists, pedestrians, motorcyclists, child passengers, and novice and older drivers. She presented an overview of her research and her advocacy for road safety policy, focusing on her bicycle safety policy fellowship, non-motorized traffic monitoring research, farm equipment and vehicle interactions research, and driver histories in bicyclist/pedestrian crashes research. Each of Prof. Hamann’s projects are discussed in more detail below.

Policy Fellowship: Increasing Bicycling Safety: Translating Research, Community Engagement, and Policy

In 2016, Prof. Hamann used her research to influence policy and engage the community to improve bicycling safety. In recent years, the number of bicyclists has increased, but the rate of bicycling-related injuries and fatalities has also increased. To solve this problem, Prof. Hamann partnered with the Iowa Bicycle Coalition. Together they focused on state-level changes to improve bicycling safety with three main goals: (1) requiring drivers to change lanes to pass bicyclists; (2) increasing penalties for driver distractions; and (3) increasing appropriations for bicycle infrastructure. As a result of their initiative, distracted driving became a primary offense with increased penalties during the 2017 legislative session. In addition, this study improved awareness in the community related to bicycling safety.

Research Project: Non-Motorized Traffic Monitoring

While pedestrian and bicyclist crashes are less likely than motor vehicle crashes, they are more likely to be fatal. To address this issue, Prof. Hamann and her co-principal investigator Professor Steven Spears (from University of Iowa’s School of Urban & Regional Planning) set up “counters” in Linn County to track the bicyclist and pedestrian miles traveled. With this data, they are developing models to predict pedestrian and bicycle traffic volumes and estimating the regional miles traveled by bicyclists and pedestrians. Using these estimates, they will compute the regional injury and crash rates (per miles traveled) for bicyclists and pedestrians in Iowa. They plan to use this research to estimate the burden of injury, monitor trends over time, and advocate for policy change.

Research Project: Naturalistic Study of Farm Equipment and Vehicle Interactions on Iowa’s Roadways

There are approximately 200 crashes between farm equipment and passenger vehicles each year in Iowa.[i] Drivers of the passenger vehicles are more often at fault and are more likely to be injured. Prof. Hamann plans to collect information about the circumstances surrounding these crashes, focusing on how passenger cars interact with farm equipment (e.g., how often passenger cars pass farm equipment, whether they only pass in passing zones). Prof. Hamann partnered with researchers in the College of Engineering, who developed a “black box” with cameras and GPS to put on the farm equipment to gather information about the passenger vehicles and to measure the farm equipment’s exposure to the roadways. Using some of the data collected from these “black box” videos, Prof. Hamann worked with a community advisory board and developed a community campaign to improve passenger vehicle drivers’ awareness regarding farm equipment. They promoted this campaign in a small town in Iowa and will evaluate whether driver behaviors surrounding vehicle equipment change.

Research Project: Driver Histories, Charges and Convictions in Bike, Pedestrian, and Motorcycle Crashes

There are approximately 677,000 injuries and 6,300 deaths annually for bicyclists and pedestrians, and crashes with a motor vehicle are the most severe. Prof. Hamann focused on the drivers involved in these bicyclist/pedestrian crashes, addressing two primary questions: (1) How often and what type of charges and convictions are given to drivers involved in bicycle- and pedestrian-motor vehicle crashes? and (2) Are drivers who hit bicyclists or pedestrians worse drivers than the general driving population?

Through this study, Prof. Hamann found that only 30% of drivers are charged in these crashes, and 70% of these charges result in a conviction. Younger drivers and drivers listed as a contributing cause were more likely to be charged. However, if the bicyclist or pedestrian was a contributing cause of the crash, the motorist was less likely to be charged, even if they were also a contributing cause. Additionally, drivers who had hit a bicyclist or pedestrian were 2.6 times more likely to have had one or more charges in the three years preceding the crash, compared to general population of drivers.

Prof. Hamann concluded that drivers who hit bicyclists or pedestrians are a high-risk group, creating potential for targeted intervention. In addition, she concluded that the state can reduce bicyclist/pedestrian crashes by increasing citations or penalties for any type of traffic violation.

Overall, Prof. Hamann provided an informative perspective on the role of public health research in improving road safety. She highlighted the importance of communicating this research and using this research to advocate for change at the state level. For more information on Professor Hamann’s extensive research aimed at improving road safety, see https://www.public-health.uiowa.edu/people/cara-hamann/.

[i] Konstantina Gkritza, Michael James Baird, and Zachary Hans, An Assessment of Traffic Safety in Urban Deer Herd Management Zones in Iowa, Tech Transfer Summaries (2010).


-Madison Murhammer Colon