Riding a bike in the city can be scary. If you’ve ever done it, you’ve probably had at least one close call — it comes with the territory. In 2016, 840 cyclists were killed in motor vehicle crashes in the United States. Over 70% of those took place in urban areas, where there tend to be more cars and bicycles on the roads.

The number of cyclist fatalities due to car accidents has increased over the last decade, up from 628 fatalities in 2009. This is likely, at least in part, the result of more people bicycling nationwide. Nearly 864,000 people reported commuting to work by bicycle in 2016, a 50% increase from 2000.

Though the booming bicycle commuting trend has been tapering off in the last few years, falling 4.7% from 2016 to 2017, some major cities still have seen consistent growth in commuter cycling. Not surprisingly, most of these cities also have invested in bicycle infrastructure such as adding bike lanes, reducing speeds on city streets, and making it easier for bicycle commuters to take their bikes on public transit.

An increase in bicycle-related infrastructure not only leads to more cyclists hitting the streets, but also can lead to a decrease in cycling fatalities. Studies have shown that areas with bike lanes — especially protected lanes that provide a barrier between cyclists and moving traffic — are safer for cyclists. The installation of protected bike lanes in New York City has been shown to reduce all traffic-related fatalities in the areas of installation.

This may explain the weak correlation between between the number of cycling fatalities and the percentage of bicyclists in a given city. Some cities are just far safer for bicyclists than others.

Other factors that influence the bicycle fatality rate in a city are climate, which causes seasonal fluctuations in the biking population, speed limits, tourist drivers, distracted drivers, and alcohol consumption.

Click here to read about the safest and most dangerous cities for bikers.

To identify the most dangerous (and safest) cities for bikes, 24/7 Wall St. reviewed the number of bicyclists and riders of other pedal-driven vehicles who died in traffic crashes in 2016 — the most recent year for which data is available.

The fatality rate is defined as the number of deaths from crashes per every 1 million people and was obtained for the 32 U.S. cities with populations of 500,000 people or more from the National Highway Traffic Safety Administration. The percentage of residents commuting to work by bike came from the U.S. Census Bureau’s 2017 American Community Survey. Population data is for 2017 and also came from the Census.