The path of least resistance?

Where I live we have three types of thoroughfares: roads, shared-use paths (commonly known as bike paths) and sidewalks.

Roads are for motor vehicles and bikes; pedestrians if there are no adjoining sidewalks. Sidewalks are for pedestrians and bikes (unless buildings abut the sidewalk, in which case bikes are prohibited). Bike paths (officially known as shared-use paths, even though some have “bike path” in their names) are for bikes, pedestrians, joggers, skaters, skiers, equestrians…

How do bikes fit into all of this? Some of the trails are toll roads if you’re on a bike but not if you’re walking. We have no toll roads for cars in this state. I have seen rants in the newspaper (or heard them from people) that bikes don’t belong on rural roads – they should stick to the paths. I’ve heard rants that bikes don’t belong on other roads because they go too slowly. I’ve seen rants (on a neighborhood app) about bikes that go too fast on the paths. And I’ve seen claims that bikes on sidewalks are illegal (as noted above, they are illegal in only a very limited downtown area where I live).

So where does that leave bikes? Not wanted on the roads, not wanted on the paths, not wanted on the sidewalks. Too slow for the roads, too fast for the paths, just plain dangerous on the sidewalks.

I have written before about John Forester‘s concept of vehicular cycling. Back in April of 2018 I wrote a series of posts about bike safety. This time, I’m here to talk about the conundrum. Our society has not yet decided whether to consider bikes toys or a mode of transportation; partly because there is no reason they can’t be both. How we are using a bike should be a determining factor in where we ride. Generally I prefer to ride lightly-traveled streets – both in town and in the country. Whether going fast or slow they seem to work best. (Jarjour, et al in Environmental Health, 2013, found lightly-traveled bike boulevards reduced cyclists’ exposure to environmental pollutants from vehicle exhaust – a result that should make you say “duh”, but should also make you rethink riding on busy streets.)

The purpose of traffic laws is to standardize and define relationships and expectations among users in order to increase safety. In grey areas, the most vulnerable user should have the right of way.We are responsible for each other’s safety and ultimately we are all responsible for our own safety. A law will not protect us from a multi-ton vehicle. Common sense should be our guiding principle.

Drivers are often advised that it is safest to drive at or near the prevailing speed of traffic rather than strictly at the speed limit; thus they may be going slower or faster than the posted speed at times. Going faster is always illegal, regardless of the “prevailing speed”.

Q. Isn’t slower always safer?
A. No, federal and state studies have consistently shown that the drivers most likely to get into accidents in traffic are those traveling significantly below the average speed. According to research, those driving 10 mph slower than the prevailing speed are more likely to be involved in an accident

“It has been found that motorists are generally capable of determining the driving speed that is reasonable for prevailing road and traffic conditions unless there are some roadway conditions that they are unaware of or which are not readily apparent and that the majority will subsequently adjust their speed accordingly. The 85th percentile speed, the speed at or below which 85% of the vehicles travel a particular roadway, has been found to best represent this perceived ‘reasonable’ speed.

I would argue that 85% of motor vehicles exceed the speed limit on 25 mph residential and urban streets. Yokoo, et al (Traffic Injury Prevention, 2019) found that “speeding is widespread…” in Minneapolis/St Paul. Hu and Cicchino (Injury Prevention, 2020) and Jones and Brunt (Journal of Epidemiology and Community Health, 2017) argue for speed limit reductions in Boston and Wales, respectively. Apparently motorists can determine the safe speed but that doesn’t mean they/we adhere to it. The 85% rule appears to be most applicable for highway speeds.

 Urban shared-use paths require care and vigilance. Travel slowly enough not to spook other users and to be able to react to their sudden moves. Calling “On your left” frequently results in pedestrians looking over their left shoulders while unconsciously moving to the left into your path. That’s why I use a bell in the city (and most of my bike path use is at 6 AM when there are few people walking). People seem to do better at localizing the sound of the bell and moving appropriately. I have no evidence to support this beyond personal experience. (Lack of evidence is not the same as evidence against. It just means I can’t find that anyone has studied this.) The Next Door app in my neighborhood is currently exploding with a thread about e-bikes on shared-use paths.

The same standard that applies to motorists appears safest for bicyclists. If you are going to be traveling fast, stay on the street (or rural paths that are known to be used primarily by bikes). If your town has “bike boulevards”, they tend to be safer, with infrastructure designed (sort of) or retrofitted for bikes. (Walker et al. define bicycle boulevards as “low-volume and low-speed streets that have been optimized for bicycle travel through treatments such as traffic calming and traffic reduction, signage and pavement markings, and intersection crossing treatments.” [Fundamentals of bicycle boulevard planning & design. Prepared for the Portland State University Initiative for Bicycle and Pedestrian Innovation.2009])

Eric Minikel studied bike boulevards in Berkeley, CA, comparing them to adjacent streets and found:
“Using police-reported collision data and the city’s cyclist count data, this study finds that Berkeley’s bicycle boulevards do indeed have lower collision rates for cyclists than their parallel arterial routes. This is true for all six bicycle boulevard–arterial pairs for which data are available, with risk ratios ranging from 1.8 to 8.0. This is true whether only reported bicycle–motor vehicle collisions are examined or bicycle–bicycle, bicycle–pedestrian and single- cyclist incidents are included as well.” (Accident Analysis and Prevention, 2012)

If you are going to be traveling slowly, use urban paths. Personally, I see very few times that a sidewalk is safe. Motorists backing out of driveways (or turning into driveways) are not looking for bikes. They are not looking for anyone traveling faster than walking speed. Small children on bikes may be going at walking speed, but are so low as to be all but invisible to motorists. Learning to ride a bike on the sidewalk in front of your house may be fine, but traveling any distance on a sidewalk is probably not very safe for a young child.

Forester recommends riding like a vehicle – stay right except to pass, turn left from the left lane. He essentially argued that bikes should be integrated with motor vehicles and that separate bike lanes cause more dangerous situations at the inevitable intersections between bike and car – e.g. bikes turning left across multiple lanes of traffic from a bike lane on the right, cars turning right across bike lanes going straight. A completely separate bike path inevitably intersects roads, and motorists who have learned to be unaware of bikes (since they are not on the roads) will inevitably be more dangerous when they do have to meet. Apologies to Forester if I misrepresent him by merging my thoughts with his.

I would argue that bike paths have their place and that they require the same style of riding as do streets – with the understanding that the other “vehicles” with which you are sharing the road are roller bladers, kids, strollers, dogs, beginning riders; instead of cars and trucks. I think he is right that bike lanes create a false sense of security and result in greater danger (cars parked in the bike lane, parked cars opening doors into the bike lane, cars in right turn lanes turning right across the path of bike lanes that continue straight). I would argue that riding as close as practicable to the prevailing speed of traffic is safest – thus slower on shared-use paths and faster on roads.

While this column did not start as an argument for bike boulevards, they seem to deserve serious consideration. In many cities there are parallel roads. I would argue for using the less-traveled route while on a bicycle. Minikel shows that crashes are less-frequent on bicycle boulevards than on adjacent routes, but is this due to the boulevard infrastructure or just the relative dearth of traffic? Where one route is less-traveled than another, common sense would hint that the less-traveled route is safer for bikes. Is the infrastructure a major determinant? Mulvaney, et al (Cochrane Database Systematic Review, 2015) set out to determine whether infrastructure could be credited for increased safety. They concluded “Generally, there is a lack of high quality evidence to be able to draw firm conclusions as to the effect of cycling infrastructure on cycling collisions. There is a lack of rigorous evaluation of cycling infrastructure.” They judged the quality of most evidence as low and preliminarily hinted that 20 mph speed limits may help and that roundabouts may be dangerous for cyclists.

Personally I tend to avoid urban shared-use paths because I have to treat every intersection as a yield sign in order to protect myself from cars, and I have to ride more slowly than I’d like to when commuting during daytime hours when others are out. There are routes where the street alternative is worse, so I choose routes on a case-by-case basis. (And some are too pretty not to ride on.) My daily routes to and from work were chosen by trial-and-error and adapted over time.

As in almost everything I read for work, “further study is warranted” and “there is a dearth of quality evidence”. As always, common sense should be your guide, and common sense is less common than it ought to be.

As Rodney King (1992) asked, “Can we all get along?”

Helmet? Hell yes!

Bicycling magazine recently republished an article with the clickbait headline “It’s Okay If You Don’t Wear a Bike Helmet”. Clearly, the implication was that helmets are not really very useful.

The article went on to talk about safer bicycling infrastructure – but it doesn’t have to be an either/or situation. Should we stop designing crumple zones into cars because we shouldn’t crash them in the first place? Should we toss out airbags, seatbelts, and carseats for kids? None of those are useful when nothing goes wrong. We work for the best and plan for the worst.

What does the evidence say about helmets? And how good is that evidence? A quick review: when we look at evidence, we consider “levels of evidence”. Different authors define those differently but, generally speaking, the highest level of evidence is a systematic review of randomized controlled trials (Meaning, for the non-scientists among you: looking at not just one, but many studies of the same phenomenon; and not just observing what happens in retrospect, but planning a test, assigning people randomly to groups, and looking at what you are studying in relation to a control group. A few definitions: randomized – people are assigned to one of two or more groups randomly, so that the groups should look the same; double blind – neither the participant nor the observer knows which group the participant is in; placebo-controlled – the group that doesn’t get the test intervention gets something that looks the same but should have no direct effect on the condition studied.) Expert opinion is the other end of that scale.

Randomized controlled trials are not always possible. The article “Parachute use to prevent death and major trauma related to gravitational challenge: systematic review of randomised controlled trials” (Smith & Pell, British Medical Journal, 2003) points out the difficulty of testing some hypotheses. They concluded:

“As with many interventions intended to prevent ill health, the effectiveness of parachutes has not been subjected to rigorous evaluation by using randomised controlled trials. Advocates of evidence based medicine have criticised the adoption of interventions evaluated by using only observational data. We think that everyone might benefit if the most radical protagonists of evidence based medicine organised and participated in a double blind, randomised, placebo controlled, crossover trial of the parachute.” (Smith & Pell 2003)

Further, Yeh, et al (BMJ,2018) in the PARACHUTE trial, conducted a randomized (but not blinded) study of parachute use in “Parachute use to prevent death and major trauma when jumping from aircraft: randomized controlled trial”. Their outcome measures were death and ISS (Injury Severity Score). Come to my workshop for an explanation of ISS. They concluded:

“Parachute use did not reduce death or major traumatic injury when jumping from aircraft in the first randomized evaluation of this intervention. However, the trial was only able to enroll participants on small stationary aircraft on the ground, suggesting cautious extrapolation to high altitude jumps. When beliefs regarding the effectiveness of an intervention exist in the community, randomized trials might selectively enroll individuals with a lower perceived likelihood of benefit, thus diminishing the applicability of the results to clinical practice.” (Yeh, et al, 2018)

We can extrapolate from the above studies that we cannot conduct an RCT (Randomized Controlled Trial) to truly test the efficacy of bike helmets. We can also conclude that careful reading is important, lest we draw the wrong conclusions, or accept the conclusions drawn in articles in the popular press about the study .

So what do we have? Olivier and Creighton, writing in the International Journal of Epidemiology (2016), reviewed thousands of studies. 40 met the inclusion criteria and were included in a meta-analysis, with data from >64,000 injured bicyclists. For those who only like to read abstracts, we’ll cut to the chase:

“Bicycle helmet use was associated with reduced odds of head injury, serious head injury, facial injury and fatal head injury. The reduction was greater for serious or fatal head injury. Neck injury was rare and not associated with helmet use. These re- sults support the use of strategies to increase the uptake of bicycle helmets as part of a comprehensive cycling safety plan.” (Olivier & Creighton, International journal of Epidemiology , 2016).

For a few nuggets from that study: “In a recent Australian study of linked police and hospital data for cyclists in motor vehicle collisions, 34% of hospital-admitted cyclists had a head injury and 15% had a serious head injury.2 In a coroner’s review of cycling fatalities in Canada, 55% of deaths were caused by head injuries.3” Also note that “neck injury was rare and not associated with helmet use.” One of the objections to helmets I have seen raised (by both bicyclists and motorcyclists) is that they think they increase the risk of neck injury. Olivier and Creighton found no such correlation.

Looking at individual studies cited, the risk reduction for head injury attributable to wearing a helmet was 85% in one study and about 30% in another (though 70% for severe injury as assessed by the AIS (Abbreviated Injury Scale). Come to my workshop for an explanation of the AIS.

The argument is often made (and is made in the Bicycling article) that wearing a helmet leads to riskier behavior. This is a phenomenon actually studied with all safety devices. Some studies assert “reduced cognitive control” while wearing a helmet. Several of these analyze the behaviors of subjects playing computer games, in which the “risk” is theoretical in the context of playing a game. One which did look at bicycling behaviors noted that male cyclists rode at a slightly higher speed when wearing a helmet. This was not true of female cyclists. It should be noted that the helmeted riders rode at 19.2 km/h (a whopping 11.9 mph) compared to 16.8 km/h (10.4 mph) and that anyone who had previously worn a bike helmet was excluded from the study.

Anecdotal evidence is at the bottom of most evidentiary scales, if included at all. Your author once crashed at about 1 mph (stopping at a stop sign, hitting a patch of ice with front wheel, and falling to the left side, striking the head). It happened so fast that I remember hearing my head bounce off the pavement at about the same time that I realized I was going down. The impact cracked the helmet but caused no ill effects. It was only after trying to get up (and slipping) that I was aware of the ice. The speed of travel did not appear to mitigate the effect. It might be noted that crashing at a higher speed could result in reducing the direct impact of head to pavement (as you could hit it sliding, rather than directly, and the head might not be the first body part to hit). Think about falling directly onto pavement on your head at zero speed. Does that sound harmless?

I grew up in the pre-helmet era. (Truth be told, I remember the first time we got a car with seat belts, and I also remember children’s car seats as being entertainment devices, not safety devices. Our car seats were made of aluminum, lightly padded and covered in vinyl. The belt was a ¾ inch wide vinyl strap. There was a steering wheel with a horn button.)

I moved to California as an adult in 1984. Some people wore helmets out there. Virtually no one did when I left Wisconsin, but they were widespread when I returned. (Let’s just agree to dispense with the “I didn’t have ‘x’ when I was a kid, and I survived…” argument. See paragraph two.)

The first helmets were essentially leather “hairnets” worn by some bike racers. The first consumer bike helmets were hot and heavy. They were worn only by nerds. The Bell V-1 Pro, introduced in the mid-80s, was the first helmet that offered protection and caught on widely (and note that it looks like a sturdier version of the leather hairnet – that was not an accident).

I was riding in the mountains when I came up on a downhill turn, sharper than it first appeared. My bike was in need of a headset at the time, so it chattered under hard braking. I scared myself on that turn and went straight to a bike shop. I dropped off the bike for a new headset and bought a Bell V-1 Pro. I have not ridden without a helmet since then.

Who am I to pontificate about helmet use? So far, I’d say there has been less pontificating and more reviewing evidence. That being said, it is probably clear by now that I come down in favor of helmets. (Especially if you read the title.) We have discussed infrastructure and safety here before. (And will again in a post very soon – written before this one but awaiting final revisions.) Not crashing is better than crashing. Prevention beats mitigation; but we will never prevent 100% of crashes and if you’re the one crashing, despite your best efforts, you might want that mitigation. Very few of us expect to crash. But that’s how I make my living.

I have spent the past 20+ years working in a large teaching hospital. I have spent most of those in a Level 1 Trauma Center. While some people plan to be in a hospital (for elective surgeries) or spend a lot of time in them (for management of chronic conditions), most of the people I work with had no intention of winding up under my care. I have learned, over the years, what injuries are likely to result with and without lap belts, shoulder belts, and airbags. And I learned why school bus drivers used to yell at you to keep your hands inside the bus. I have seen the arms that got trapped under cars and dragged along the pavement, and helped those folks with their rehab. (I no longer rest my arm on the windowsill when I drive, but that’s just me.) I know what you’re likely to break falling from a ladder, the difference in what young and old people tend to break in similar falls. I also have seen that people without helmets tend to have worse head injuries than those with helmets, that other injuries are pretty similar (mostly clavicle and rib fractures), and that those with head injuries tend to fare worse in both the short- and long-term.

We can also look at it from a business perspective – a risk/benefit analysis.
*Risk of not wearing a helmet – brain injury, death. Benefit of not wearing a helmet – better hair or the feeling of the breeze in your hair (probably not both).
*Risk of wearing a helmet – matted hair or not looking cool. (Some would argue that you have a greater chance of doing something stupid, but I’d say alcohol is the hands-down winner for that risk.) Benefit of wearing a helmet – reduced chance of head injury, bigger reduction in the risk of serious head injury or death.
You may consider other risks and benefits, but I think it would be hard to come to a different conclusion.

While we’re at it, how often do you see families out together; the kids are wearing helmets, the parents are not? What message does that send to the kids? The way I see it, you are telling your children “helmets are kids’ stuff.” We know most kids want to feel grown up and many want to be like their parents. You can bet that, as soon as possible, kids will ditch the helmet to feel grown up. I see many middle school kids using helmets as handlebar decorations. If you are a parent and ride a bike, think about helmets – are you putting helmets on your kids because other parents might yell at you if you don’t? Are you doing it because you think helmets will make them safer? If the latter, then why don’t helmets make you safer? If the former, why don’t you have the guts to stand up for your convictions? (And exactly what are those convictions? Do you think you are battling courageously the nanny state?)

So you can take my word for it as an expert, or as someone who has personally experienced crashing and hitting my head, or you can read the literature. In all cases, I think you’ll find that you’re better off with a helmet than without. (And maybe you’ll find one story of someone who was somehow injured by wearing a helmet. An early argument against seatbelts in cars was that you would get trapped in a burning car and die because you wore a seatbelt. Yes, that has happened; but less frequently than people have been thrown from cars – through the windshield, a window, the sunroof – and killed because they weren’t wearing a seatbelt; which is not to mention the multitude of injuries sustained by those flying around in a rolling car even if they don’t fly out through an opening.) Since most of you will not crash and hit your head, you can play the odds if you choose; but then we’d have to look at the public health consequences and the societal costs of your choice. That would be fodder for another post.

(Complete citations available on request – but you oughta be able to find the articles if you try, and have access to PubMed.)

Vitamin D…in November?

It was a tough day of synthesizing vitamin D from sunlight. Hey, you think it’s easy – sure, it’s easy in July, but much harder in the November sun, especially when you’re also running the Krebs cycle and synthesizing ATP as fast as you can.

Check out the stats from today’s ride on my computer readout. If it’s hard to read, net mileage was zero (I ended where I started) gross miles zero (none of the miles were gross – they were all fun). Net climbing zero again – I started and ended 856 feet above sea level. Gross was just enough to reach the top of every hill. Average speed – yup, average. Total miles exactly equaled the distance from my house back to my house. Heart rate was non-zero throughout.

The plan was to ride north, but there was a strong southern breeze so I rode east and south so I could ride home with a tailwind. It actually worked. At each junction I rode whichever way looked best. Hope, Cottage Grove, Deerfield, Stoughton (where even the cheese (kaese) is Norwegian) and various points in between. No maps, no apps. I rode enough so that I drank the last of my water on the last block coming home. The important statistic was 70 degrees (21 Celsius) and sunny – not at all normal for November in Wisconsin, but I’ll take it. The corn is dry and this may be the last week to get it harvested in good weather.

Hope is the word of the day. I woke up to the first full day with a new President-elect. Democracy may survive this. Be on the lookout. The rash of lawsuits contesting election results being filed by the Trump campaign is a misdirection. Watch for a slew of Executive Orders attacking environmental protection, healthcare, worker’s rights, and education in the next 10 weeks. His minions will be working overtime in the shadows to inflict maximum damage. Civil rights will come under attack, except for that second one about “an unregulated militia” – oh wait, that says “well-regulated militia”. One man’s militia is another man’s domestic terrorist group.

AP Photo

This photo accompanied an article quoting a Dallas evangelical pastor calling Trump “the most pro-faith president in American history.” The smirk on Trump’s face says it all – “I’ve really put one over on these dupes.” With his history, one can only assume he is sleeping with his spiritual advisor (the one with her hand on his right arm). I’m surprised no one is kissing the hem of his garment (or would it be the end of his tie?) or his ring.

Her oratorical skills are unmatched.

Primož Roglič of Slovenia entered the penultimate day of La Vuelta a España with a 45 second lead over Richard Carapaz of Ecuador. By the end of the day the lead was down to 24 seconds, the final margin after more than 72 hours of racing.

From NBC TV – Richard Carapaz, Primož Roglič, Hugh Carthy (left to right)
Possibly the last ride of 2020 just for fun. I don’t usually do selfies.

What’s wrong with this bike?

Image from

How about this one? Maybe a closeup will help.

Image from

If you said “nothing”, you’re right. There is nothing wrong with these bikes…as long as you have about $6000 to spend.

On our FAQ page, we asked and answered the question “Is it cheating to ride an e-bike?” The world of e-bikes is changing. Some are 75 pound behemoths that drive themselves – until the battery dies. The two pictured above weigh around 26 pounds – about the same as my Bruce Gordon touring bike. Even when the battery dies, pedaling these bikes is no big deal. Where is the motor? you ask. Nearly invisible, in the rear hub, I answer. A close look between the cogset and the brake rotor and you might see the hub diameter looks a bit large – sort of like the 3 speed hub on my Spot Brand bike – but small enough to be virtually invisible.

the Bruce Gordon

E-bikes are now a lot like other bikes – available as commuters, cruisers, mountain, gravel, and road bikes. They can be pedal-assist, or can have a throttle like a motorcycle. Top speed is governed in multiple classes – you get to pick. With the motor not assisting, you can go as fast as you want (or can). Possibly the ultimate niche for them is the cargo bike. I was going to include some images, but there are too many variants – just search the term.

Would I ride an e-bike? No. It might be like a jet ski or a snowmobile or crack cocaine. Once you try it, you don’t want to give it up. Or so I’ve heard; never having tried any of them. Though the e-bike doesn’t have the societal costs of the others. A half-fast friend recently went bike shopping. His partner wanted an e-bike and bought one. He tried one and almost did it – but the Colnago won out and he couldn’t afford both. (But, as you see below, it was a false dichotomy – don’t tell him.)

This might qualify as bike porn – pictures of $5000+ bikes that most readers can’t afford and maybe have no business riding even if they can. We’ve all seen the stereotypical e-bike. Today, we just wanted to say the market has expanded. There are lots of choices. Just get out and ride; or do whatever it is that you love and will get you off the couch. (And no, I don’t have links for you to click to buy these and get me a commission. If you want to buy a bike, you’re on your own.)

As we said in the FAQ – if e-bikes get people riding who wouldn’t otherwise, we’re all for them. If they’ll get you out more, more power to you. If it’s just another expensive toy, don’t you have enough already?