BLINDSPIN 1: Does it make sense to ride a bike with your eyes shut?

We are starting a research project which sounds completely insane but is not: we want to know what happens when a person rides a bicycle with his eyes shut.

The idea is not completely insane because the same principle — the visual occlusion method — has long been used in automotive safety research.  It is a powerful tool for studying driver distraction.  Most members of our ad-hoc team have scientific experience with the technique (but we are working in our free time on this project). First, some background.

Collaborators: Jakke Mäkelä, Niko Porjo, Tuomo Kujala, John Senders

What is the point?

Bicycling has been around for more than a century, but how much do we actually know about what could make the actual process of cycling safer? At the moment, cycling safety is more or less all about passive safety: cycleway design, design of crossings, helmets, visibility, audible alarms.

What about the process of cycling? What makes one cyclist safer than another? Are the elderly risky drivers, or the very young? What kinds of situations are the most dangerous? How and why does cycleway design affect cycling safety? (For a critical look at some cycling safety issues, see post “Does it make sense to bike without helmet?“).

Passive driving safety. This is the normal approach. Source: Ontario Ministry of Transportation


Those questions are too wide to be answerable, and it is necessary to narrow the focus. One area to look at is driver distraction, if only because no one has really done so. For automobiles, driver distraction is a serious study subject and has its own conferences. Cyclist distraction is only now emerging. The scientific literature seems to consist of just a handful of papers from the last year or two, and almost no field tests.

We want to ask a very simple question: how dangerous is cyclist distraction?  There are lots of accident statistics around, but they tend to look at the cyclists as victims. To put it politically incorrectly, we want to know about the cases in which the cyclists are “perpetrators”.

[Of course one never actually uses that term in research. When trying to study or prevent accidents, it’s pointless to “blame” anyone. Mistakes are made, accidents happen, and the important thing is to understand the mistakes so that further accidents can be prevented. But the term “perpetrator” is easy to understand].

This needs to be narrowed further: what do we even mean by “cyclist distraction”? Does a cyclist need to keep his eyes focused on the road all the time? Is it safe for him to glance at his watch? Could he safely talk on the phone (with a handsfree set of course)? We lack data on basic questions like this.



Distracted cycling. How dangerous is this in reality?  Source:


What is the visual occlusion method, and what can it tell us?

We will write more on this in the next few weeks. In brief: an occlusion test determines how tightly a driver needs to keep his eyes on the road. Not every glance away is equally dangerous, and short glances happen constantly (for example, glancing at the speedometer takes about half a second).

In practice, the driver wears a pair of special electronically controlled goggles which can be quickly switched between transparent and opaque modes. A few companies manufacture such goggles, but since we have no budget, we will hack ours from a pair of 3D glasses.

At any given moment, the driver can control whether he sees the road or has to drive blind. The driver has full control, and drives at a level where he feels no danger; any accidents would make the tests invalid, since the aim is to look at safe behavior and not risky behavior.

A video shows how this was done in the 1960’s: Pioneer Days on Rt 128. A very funny yet very serious article on the subject has been published in the Boston Globe. John Senders, the principal investigator in those experiments, is also a member of our team — in fact, he is the one who proposed this experiment in the first place.



Occlusion tests in the 1960’s. Photo Michael Dwyer/AP. Source: Boston Globe.


Since those days, laboratory simulators have been used because there are some legal and ethical issues in driving blinded on normal roads. However, it is difficult to simulate bike driving in a laboratory. We will need field tests.

The results from an occlusion study can be rather obscure, and not simple to explain. Roughly, we expect to find two critical values:

*The time duration above which it is definitely unsafe to keep the eyes closed (or focused on something else). For car driving, this time is about 1.5 seconds. We have no idea what it will be for cycling.

*The distance which a cyclist is able to move with his eyes closed. This is typically 5-20 meters for car driving.

These numbers cannot be used immediately for practical applications, but they are necessary background. The time could be used to evaluate whether (for example) mobile phone use is less dangerous or more dangerous than when driving a car;  the distance could help in designing cycleways, since it gives an indication of what types of obscurations are particularly dangerous.

Who is doing this, and why?

Currently, our ad hoc group has four people with research or technical backgrounds.  It is difficult to get funding or ethical approval for a project of this type, so we are doing it without any. This is a spare-time effort without any input from our employers.

All of us work in our spare time because we believe this research is interesting and important. Because there are risks involved, we will mostly need to self-experiment. However, to gain a large enough data set, we are seeking volunteer test subjects who have moderate streak of lunacy.

*Jakke Mäkelä (LinkedIn) worked in an automotive safety research project in 2013-2014, and is familiar with occlusion methods. He is in some vague sense the unofficial project leader, to the extent that there is one.

*Niko Porjo (LinkedIn) is a technical wizard. He will be hacking the occlusion goggles and working on data collection.

*John Senders (home page)  is one of the pioneers in the field of visual demand (and is featured in the video above). He proposed the idea of studying cycling visual demand in the first place. He will work on theoretical aspects in particular.

*Tuomo Kujala (LinkedIn)  has studied visual demand in automotive environments, and has done extensive visual occlusion studies. He will try to relate this project to earlier research and will work on data interpretation.

We are open to adding new people to the core team, especially experts in cycling safety.


What do we plan to do next?

1. First and foremost: we plan to self-experiment and take the personal risks before we allow anyone else to participate. We don’t think there are any real risks, but… We will report our results on this blog as we get them. The figure below shows some pre-pre-pilot results, but those mainly show that the data collection method works. Critical technical parts of the experiment are still missing.



Results from pre-pre-pilot, subject A. A drove along a straight isolated track of cycleway, and pressed a button whenever his eyes were shut.  The blue line is speed in kmh. The red lines are above 12 when A kept his eyes shut, below 8 when he had them open. 

2. We plan to seek volunteers in July-August 2014 in the Turku region. Self-experimentation is useful up to a point, but it does not give a large enough dataset. The experiment is actually much safer than it sounds, but it does require a certain amount of craziness in the volunteers. We already have a few such volunteers lined up, but we could almost certainly use more.

3. We plan to publish the results. Even though this is a free-time zero-budget project, we seriously aim to get peer-reviewed results. If we cannot get published in a peer-reviewed scientific journal, we will publish on this blog.

If you are a moderately insane cyclist in the Turku region, and are potentially interested in volunteering, please contact Jakke.Makela{at}

See also Blindspin project page.