Over the past two decades, the number of people injured in bicycle accidents in the U.S. has been rising and the cost of each crash has also gone up, according to a recent study. The increases in accidents and medical costs are partly the result of increased ridership overall, the researchers write online June 1st in the journal Injury Prevention, but the higher cost per accident is mainly driven by larger numbers of riders over age 45 and more street and highway crashes that may involve cars.

“We advocate for cycling, as the proven health benefits certainly outweigh the potential health risks,” said senior author Dr. Benjamin Breyer of the University of California, San Francisco.

“Our hope is that by quantifying these costs it will help to spur discussion and policy surrounding infrastructure for safe cycling,” Breyer told Reuters Health by email.

Past research has shown that the number of bicycle–related accidents leading to hospital admission has risen dramatically, the researchers write.

To determine how medical and quality of life costs related to bike crashes are evolving, the study team used data collected between 1997 and 2013 on adult bicycle injuries.

The data on nonfatal crashes came from the National Electronic Injury Surveillance System while the fatal crash data was from the National Vital Statistics System.

The research team also used cost estimates from the Consumer Product Safety Commission’s Injury Cost Model to determine costs of work missed and quality of life lost due to crashes.

They found that 3.8 million nonfatal adult bicycle injuries and just under 10,000 deaths were reported between 1997 and 2013.

The total cost of bicycle injuries over the study period was $ 209 billion for nonfatal injuries and $28 billion for bike–related deaths.

The number of nonfatal biking injuries increased by about 6,500 each year and the total costs rose by an average of $789 million annually. But the injury costs per mile traveled by bike fell from $2.85 in 2001 to $2.35 in 2009.

Overall, the costs of nonfatal biking injuries rose by nearly 140%, from $9.3 billion in 1997 to $22.4 billion in 2013.

Over the study period, the share of costs attributed to riders over age 45 rose steadily by about 1.6% each year. Bicycle–related deaths also increased for people over 45 and decreased for those under 45.

In addition, crashes occurring on streets or highways played an increasing role, with their share of the total costs rising by 0.8 percent each year.

“Encouraging people to use bicycles must occur along with building safer cycling infrastructure such as cycle tracks and better street lighting,” said Morteza Asgarzadeh, a researcher at the Harvard T.H. Chan School of Public Health in Boston.

“Bicyclists, especially the older sub–populations, should become well–informed about the risks they take by using bicycles,” Asgarzadeh told Reuters Health by email.

Although building biking infrastructure is expensive, it could ultimately help bring down costs due to crashes, Breyer noted.

“In fact, we could build cycling infrastructure in one–sixth of the entire U.S. for the same cost of all these injuries in 10 years,” Breyer said.

Asgarzadeh advised cyclists to be vigilant and drivers to watch out for bikes and give them room on the road.

“While bicycling has many health benefits, injuries can be costly and lengthy, especially for people over 40. Prevention is still the best and least expensive way to tackle the issue,” Asgarzadeh said.

Breyer added that all cyclists should wear helmets. “The health benefits of cycling certainly outweigh the potential drawbacks. Many, many people cycle every day injury free,” he said.

—Madeline Kennedy