Research Roundup: Bike safety and city planning

University of Minnesota researchers published several studies this past month.

Nikki Pederson

Recent studies published by University of Minnesota researchers look at bike safety within city planning, herbivorous animals and premature infants’ increased risk of maltreatment.

Bicycle infrastructure within road design and city planning

Using new technology that can measure the distance between bicycles and passing vehicles, University of Minnesota graduate students studied the vehicle passing distance on various types of bicycle infrastructure within Hennepin County.

A Minnesota statute requires a minimum vehicle passing distance of 3 feet. Anything less than that is defined as “encroachment,” and can increase the likelihood of a cyclist being injured.

Within the nearly 3,000 passing events recorded, researchers Josh Pansch, Isaac Evans and Lila Singer-Berk found varied results depending on road type, vehicle type and even the gender of the cyclist.

A cyclist is more likely to be encroached upon in a bike boulevard than any other facility. A bike boulevard is a “lower-volume, lower-speed street that has been optimized for bicycle traffic,” according to the City of Minneapolis. A bollard bike lane, which uses plastic cones to separate a bike lane from the road, had the greatest vehicle passing distance of any of the bike facilities.

The study also found that as vehicle size and type increase, average vehicle passing distance decreases. This means a cyclist is more likely to be encroached upon if the vehicle is larger, including buses and semi-trucks.

Female riders are more likely to be passed closer than male riders, with female riders experiencing 73 percent of the encroachments recorded.

“Right now we’re focusing on sharing what we’ve found,” Singer-Berk said.

The implications of this study extend beyond the University. The results of the study were shared with Hennepin County and published in ITE Journal, she said.

“It means city planners … can look at our study and have more evidence in investing in protected bike facilities,” she said. “They are safer and help vehicles follow the statute.”

Herbivorous animals are necessary for healthy ecosystems

No matter the size, herbivorous animals such as red deer, marmots and insects play an important role in maintaining ecosystem functionality, according to a University study published earlier this month.

By progressively excluding vertebrate and invertebrate herbivores, researchers at the University of Minnesota, in collaboration with the Swiss Federal Institute for Forest, Snow and Landscape Research, were able to examine what happens to ecosystems when there is a lack of biodiversity.

Conducted in the Swiss National Park in Switzerland, the five-year study found that invertebrate communities such as snails, worms and some insects, were important in nutrient cycling and plant and soil function.

“The biggest take home message highlights that the little things are really important,” said Joseph Bump, a professor and collaborator on the project. “We don’t see them necessarily, but they are necessary in healthy grasslands.”

The field experiment included various enclosures that were distributed across two different vegetation types in the park. These enclosures excluded different sized herbivores. The project ran from 2009 to 2013, and almost 10 years later, the researchers are still analyzing the data, Bump said.

Preterm infants are at risk for maltreatment

A new study published this month by a University researcher found that infants who were born preterm had 1.6 times the risk of being readmitted to the hospital within the first year of life for injuries suggestive of maltreatment.

Child maltreatment is a major public health problem, and population-based surveillance and research on the issue is hindered by limited official child welfare data, according to the research brief.

Susan Mason, an assistant professor at the School of Public Health, performed the study to expand the data available. Much of the previous data was limited by inconsistencies, such as differences in how states define abuse, or changes in the size of and funding of their programs, according to the School of Public Health.