Sharrows are ineffective, so why do we keep using them?

Biking is good for your health, and it’s an effective form of transportation as well. Of course, that’s only when proper infrastructure is provided to facilitate biking as a viable form of transportation. 

Across much of America, bicycle infrastructure is seriously lacking. So what do most municipalities in the US do to encourage biking? They slap down a sharrow and call it a day. But sharrows are an incredibly ineffective way to help cyclists commute safely and efficiently. It’s long past time that we begin to seriously invest in bicycle infrastructure and move past the sharrow.

What is a sharrow?

Shared lane markings, also known as sharrows, are those painted bicycle icons you might find on many streets throughout the country. They are mainly meant as a way to help cyclists position themselves properly on the street, far enough away from parked cars and to help inform drivers of their position.

According to the city of San Francisco, shared lane roadways (roads where both cars and bikes can travel concurrently) face issues such as wrong-way riding, sidewalk riding, and notably, dooring. Dooring refers to the dangerous, and sometimes deadly, act of opening the door of a parked car into the path of a traveling cyclist.

San Francisco and many other cities have decided to use sharrows as a cheap way to alleviate the issue of dooring, as well as a way to claim they are doing what they can to enable bicycle infrastructure. In 2008, San Francisco claimed to have 208 total miles of a bike network – 132 of these miles were “shared roadways” where sharrows are present, or where cyclists are simply permitted to ride.

What’s the issue with sharrows?

Despite the seeming overwhelming amount of “bicycle infrastructure” present in the US due to the spread of sharrows, these markings are barely beneficial at best and outright dangerous at worst.

Former executive director of the California Bicycle Coalition Dave Snyder helped expand sharrows in San Francisco in the 1990s, optimistic that they would make cycling safer. Early studies showed that sharrows did have some positive effect, as riders were further from the curb, but recent research has flipped the narrative on its head.

A study of Chicago’s bicycle network from 2011 to 2014, analyzing census blocks feature bike lanes, sharrows, and no bicycle infrastructure at all, found that sharrows increased injuries the most, both doorings and overall crashes. Surprisingly, they found that roads with sharrows are actually more dangerous than roads with no bicycle facilities.

They found that on roads where sharrows were installed, roads with many bicycle commuters saw increases in injury rates. The increase in injury rate after the installation of sharrows was greater than that in increases in injuries where bike lanes were installed and where no infrastructure was added. 

The researchers were unsure of the exact reasons for their findings, but they hypothesized that sharrows gave riders a false sense of security and may influence the way they ride or the way motorists drive. They concluded that dedicated spaces for cyclists are much safer than sharrows.

Dutch traffic engineer Dick van Veen noted that sharrows on their own are ineffective, because the road itself hasn’t changed. “The speed limit and road layout remain unchanged 99% of the time, which de facto means that it is actually just a car space, in which bicycles are supposed to ride,” he said. Without road diets, reduced speeds, and changes to the structure of the road itself, sharrows do little to make things safe for cyclists.

A separate study from 2016 in New York found similar results. “Holding all else equal,” they wrote, “compared to no bicycle route, a bicycle injury nearby sharrows was nearly twice as likely to be moderate, severe, or critical.” Bicycle lanes resulted in around 28% fewer crashes and injuries. Sharrows (along with other forms of infrastructure) led to decreased risk of injury, but increased severity of said injuries.

Besides the injuries the study focused on, researchers also noted the financial costs of said injuries and deaths. They estimated that bicycle injuries and deaths cost US society more than 10 billion dollars per year. This cost comes from not only the nearly half a million annual hospital visits as a result of these crashes, but also “the loss of productive life years in a predominantly younger population preferring this transport mode.” Not prioritizing safe bicycle infrastructure costs America billions of dollars every year in the loss of life of its citizens and their working capabilities. 

A third study has also shown that sharrows can be dangerous. Despite lacking statistical significance, researchers studying cyclists in Vancouver and Toronto “found a suggestion of increased risk with shared lanes or sharrows,” again noting that sharrows are potentially even more dangerous than nothing at all.

So why are we using sharrows?

Sharrows are not completely useless, but only when used effectively. According to van Veen, 80% of urban Dutch roads are shared use, and the Netherlands is the undisputed leader of the commuter bicycling world. However, again, this only works because of design.

The mixed use of cars and bikes on Dutch roads only works because these roads are specifically designed to facilitate both. They have speed limits of 30 km/h (about 18-20 mph) – any road with a higher speed limit should have separation between bike and car travel.

Separation between cars and bikes should be a no-brainer – they’re different forms of transit, so why are they traveling together? We have sidewalks because we understand that people should not be walking where cars are driving as it is unsafe. Cycling should be the same way.

The strange American mindset

Yet for some reason, American engineers take an anti-bike stance in their design of infrastructure, and they do so consciously. As recently as of 2012, the American Association of State Highway and Transportation Officials (AASHTO) sets out anti-separation policies in their official guidebook.

“Many bicyclists will use the roadway instead of the shared use path because they have found the roadway to be more convenient, better maintained, or safer,” they write. “Shared use paths should not be considered a substitute for street improvements even when the path is located adjacent to the highway, because many bicyclists will find it less convenient to ride on these paths compared with the streets, particularly for utility trips.”

Strangely, they consider separated paths from vehicular traffic more dangerous, even despite research supporting the opposite. Researchers, in a 2011 article published in Injury Prevention, wrote that traditional American philosophy, despite not being scientifically proven, argues “bicyclists fare best when they behave as, and are treated as, operators of vehicles.”

Again, bicycles could not be more different than two-ton motor vehicles, and they should not be anywhere near each other. The same study found that when cycle tracks are provided (separate bike paths), more than 2.5 times as many people ride on them when compared with the road. Further, cycling on these separated paths led to 28% less injuries than on the road.

Once more, the Dutch came into discussion in the study, serving as a model of what to strive for. The researchers noted that the nearly 30,000 kilometers of separated bike paths have led to 27% of Dutch trips being done by bicycle, with an injury rate of just 0.14 per million kilometers traveled. In the US, just half a percent of commutes to work are done by bicycle, and “the injury rate of bicyclists is at least 26 times greater than in The Netherlands.” 

The study of Vancouver and Toronto cyclists found similar results, remarking that separation and lower speeds found in Europe are beneficial and increase the amount of cyclists in North America. 

What should we do?

It’s clear that sharrows are not enough. They’re cheap – about $250-339 each, including the cost of installation. What they really do is allow for towns and officials to ignore the very real costs of preventing proper bike infrastructure while claiming they’ve done what they can to facilitate biking. 

As Dave Snyder says, “we need separate bike paths; we need protected bike lanes on busy roads; and where the lanes are shared, we need actual speeds reduced to 20 mph or slower. Sharrows don’t do any of that.”

Ignoring our bicycle infrastructure is detrimental to everybody. A lack of walkable, bikeable cities directly impacts our health, and the lives of Americans lost not only directly impacts the people they’ve left behind but damages our economy as well. The investment in proper bicycle infrastructure is long overdue. The United States is the richest country in the world – it’s time to use some of that money to make it a better place to live.