I tried an experiment this week. On my commute, I intentionally rode slowly. Instead of pushing myself and riding hard, I just noodled along. Where I usually ride 20 mph, I rode 12-15 mph; where I usually push myself at 25 mph and up, I rode 15-18 mph.

As I expected, I got to where I was going just fine, in not that much longer a time, and without sweating or straining at all. The effort level was not much more than walking.

What I didn't expect was that I felt unsafe. Less safe, anyway.

When I was riding in the traffic lanes, cars pushed by me, leaving me less room than usual. This is on city streets without bike lanes, where cars are typically going 25-35 mph. I normally have no or minimal issues there; now it seemed like mirrors were passing way too close to me quite often.

So I have formed a theory that on that sort of city street, "the faster you ride, the safer you are." Maybe drivers treat you better if the relative speed between you and them is not too much, because you're acting like a slow car (or moped). Or, maybe it is because they feel like you're at least trying to keep up with their flow. Or, because they think a cyclist riding fast is less predictable so they better give you a wider berth. I'm not sure of the reason(s).

What do you think? Is that true, or not, where you ride?

(For Portlanders, my riding during this experiment was on NE Sandy, NE Broadway, E Burnside, SE Hawthorne, NE 20th and 28th.)

Hard to say, I'm not terribly fast, but I think you may be right. Another thing about going faster is that you minimize exposure times at places like intersections or even driveways, lowering you chance of being hit slightly.

It might be a perception thing. Cars still just a close, but relative speed between bike and car is slower and feels safer....or not.

Most roads here don't have any bike lanes.. I definetly feel safer when I ride a little faster . I don't have any proof or statistics to prove that riding faster is actually safer. When I ride on mups and sidewalks I ride slow, but when I ride on the roads I ride faster. I've also noticed that whenever I ride fast and push a little harder it keeps me more focused and aware of what's happeneing around me.

I wonder how much is just that; "feeling". I'm reminded of the gorilla suit attention test, which shows the brain's ability to filter out extraneous stuff when it focuses on a task.

I think it's possible that going faster simply requires more focus, so that your brain is simply filtering out those close car shaves. Alternatively, when you are toodling along at a speed that requires no attention at all to cadence or breathing, and less attention to your line of travel, you won't focus so much, so that more extraneous information makes it's way to your attention.

Placebo effect. Cars don't care if you're going 18 or 20 mph. Adding 2 mph requires a lot more power output, more wear on drive train, and longer stopping distance in case of an emergency. I prefer to slow down to about 15 mph when riding in crowed street. A motorist can suddenly dart into your path...lower speed translates to less damage to the body.

I agree with OP. For a few reasons I wont bore with here.
I have 'fast' bikes and a 'slow' bike. The slow bike is definitely not desirable to ride in traffic.
It seems to me that faster passing by cars also equates to more room and less get-out-of-my-way
factor than on the slow bike, of which cars most definitely squeeze more.

I don't know, maybe it is just a placebo effect... What I do know is that when I am riding on a busy arterial road with cars going by me at 40-50 MPH..I "feel" much more comfortable riding at 20++mph then 10mph.

Going slower you can probably have your head up more and see what the heck is going on around you vs in your aero tuck at ludicrous speed.

To be clear, the streets I'm talking about are the typical larger, un-bike-friendly, street in a dense city - flat, four traffic lanes, two parking lanes, no bike lane, traffic lights every several blocks, cars moving 25 mph to 35 mph with the speed limit 25 mph.

On those streets, if I'm pedaling 25 mph, I'm moving about the speed of a slow car. At 20 mph I'm slower than any car, but the cars don't pass me as quickly (relative speed). My top speed during those commutes is about 28 mph, which I can only do for a short time, and at that speed I can change lanes and pass slower cars as if I were a small scooter or moped, and traffic seems to treat me like one of those - no-one tries to share my lane. Of course, in a few blocks I am back to "slow car or slower" speeds, with my heart dangling from my chest, dreaming of a Gruber Assist ( https://road.cc/content/blog/4155-ele...e-hidden-power ) and feeling dirty . . .

When I'm moving slower than cars, I ride to the right of the lane, just out of the door zone, and in stretches with no parked cars I ride further to the right if a car is bottled up behind me. I use a helmet mirror to monitor what is going on back there. The faster I'm going, the more of the lane I take.

Here is a way to think about it. You know when you're on a city street with a downhill grade, that makes riding 30+ mph easy? Do you feel safer, vis-a-vis traffic, at those speeds?

All of the above applies only on flat roads. For me, even a slight upgrade (not even a proper hill) completely changes the options. Do you crank up the effort to hold 20 mph? If the grade is only for a couple of blocks, sure, but I can't keep that effort up for long, and the harder I'm struggling, the less alertness and bike control I have. Do you drop it down to 15 mph? Now the cars are elbowing past you, mirrors whizzing by. Do you just bail to the parallel quiet street? That's probably wisest.

I was talking about this with some other commuters, and they pointed out that when riding fast, you might be more focused and alert, not daydreaming. I've also noticed that the faster you ride, the more green lights you catch. Makes sense if the signals are timed for the speed limit. On my experiment days, I seem to spend a lot of time at red lights. I don't like red lights - sitting there waiting to be rear-ended, then trying to clip in and accelerate with a car on your butt, plus yesterday I almost got right hooked by a commercial truck when one of those reds turned green. Feels safer to go through on green.

Note: I don't regularly commute on roads with typical car speeds of 50+ mph. I've ridden on those, and I agree whatever puny speed a cyclist can come up with makes no difference there. Just stay far to the right, watch your mirror, and be prepared to dive into the bushes.

I'm thinking the test has to be repeated in another place other than metro PDX.
and more than 4 times .. then actually survey the drivers .

I'm in the slow lane out here.. Though the Trolley is slower.. it's for the tourists ..

I have also wondered about this from time to time.

JYL- In my opinion you already stated the reason why it felt less safe going slow.

"When I'm moving slower than cars, I ride to the right of the lane, just out of the door zone, and in stretches with no parked cars I ride further to the right if a car is bottled up behind me. I use a helmet mirror to monitor what is going on back there. The faster I'm going, the more of the lane I take."

In my experience lane positioning makes all the difference and I know there are tons of other cyclist who feel the same way. By moving over to the far right while going slow you are letting people pass closer and within the same lane and then it feels less safe (and probably is).

+1 It took me a while to really assert this on the road, but it makes a huge difference. Sometimes I feel like I'm being rude, despite the cars having a turn lane they can safely pass me in, but as soon as I move over to close to or in the door zone I get buzzed by somebody who can't be bothered to give me even a foot or two of space. Nowadays this pisses me off enough for me to get right back out into the lane proper and force the cars to change lanes to pass me. MUCH SAFER, and it makes my experience more pleasant. Or less unpleasant really, I don't enjoy riding on some of these roads, but I don't really have a choice in some places.

Impractical to survey the drivers, but otherwise - let's do it. Any who are interested, try riding a familiar piece of road slow and then fast, and see what you think. Did it feel different? Was there any difference in your actions (beyond speed) or in drivers' actions? What sort of road and traffic?

I do think some of this might be perception, but I also think if you are catching more red lights, that might be the biggest difference. I find the times when stopping for, or accelerating from, red lights to be the ones where I need to be the most alert for danger. Therefore, at least if it was me in this situation, I would feel less safe from going slower, but not so much because of the speed, but for being in more red light situations.


I've riding different sppeds on my commute, I haven't noticed a difference. However, my fast isn't very fast, and the cars are going 40 anyway. I prefer to go a bit slower on my way to work because of less sweat and being more ready to work when I arrive. The time saved getting in the right frame of mind at work more then offsets the couple of minutes I save by going faster. On the way home, it depends more about how I feel.

I'm not sure if it's safer or not, but I always like to book it when commuting -- I feel like it's more courteous to everyone involved if I'm going closer to their speed.

It's harder to text while riding faster, so it's not always safer.

In most cases though, the faster you ride, the fewer cars are passing you, so fewer right hooks, cars tend to hold back rather than pass, and you are generally not as much of a PITA. If you can keep up with the traffic, you are generally safer.

I totally agree, my friends never agree with me and some of them continue to ride on the sidewalk despite my preaching.

I have no evidence, but I suspect real slow bike commuters who are on the road attract a lot of ire for being on the road then faster commuters. If you are going very slow, your speed makes you appear that you should be on the sidewalk to the cagers (regardless of whether that is true or not).

I think if I dress the part (bright colours, helmet, blinkie, etc.) I get more respect more then anything to do with my speed. And while I'm sure greater visibility is part of it, I don't think it is the whole thing.

Slower is definitely less safe when riding near motorists. The speed differentially alone will magnifiy any impact.
35-22 = 13 mph impact
35-15 = 20 mph impact

On 25 mph arterials like Hawthorne, 20th, and 28th I typically take the full lane. In other words, you will find me in the middle of the lane ~1 meter away from the left. If I am on a fully loaded grocery bike and can't maintain ~20 during a climb I move over to the right (e.g. 1 meter off the curb). On Sandy and Burnside there is a wide lane and shoulder so I ride on the right (1 meter from the curb).

Its pathetic that Sandy and Burnside have stretches with 35 mph speed limits. IMO, every non-limited access arterial within PDX city boundaries should be lowered to 25 -- and some to 20.

its not about your "look". its all about them and their feelings of transportation superiority.

That very well could be part of it. I also think there is some bit of class-ism. If I look the part, I look like I have other optins ancd could be riding around in a car if I want so they are a bit more considerate around me. If I look like a long-haired hippie drunk with no drivers license on an old mountain bike or someone who can't afford a car, if they run me over, it is no big loss for society.

That math works when being hit from the rear, but is opposite in a head on conclusion or if someone pulls out in front of you.

Regardless, I'd rather not get hit at all :-)

I dunno that I buy the "slower is less safe" thing in general, but if you are more aggressively protecting your lane when you are riding faster, then I can easily see how you'd get the experience you have. Regardless of how fast you are riding, you need to ride so that you get passed safely.

Um... cagers might want you to feel this way, but tearing your legs off to keep up with motorized traffic is never going to work.

As for being courteous... I don't worry too much about it. I will not try to delay traffic, but I'm not putting an electric assist in just to appease the cagers.