Why Cyclists Hate Stop Signs

Cyclists are notorious for running stop signs and there’s probably nothing else we do that raises as much ire among motorists and provides as much fuel for the anti-bike contingent. It can be extremely dangerous, and it undoubtedly breeds an environment of mistrust between motorists and cyclists. Given the fact that most cyclists are law abiding citizens in every other regard, why do so many choose to roll through stop signs and red lights (myself included)?

Joel Fajans (bicycle commuter and physics professor at UC Berkeley) and Melanie Curry (bicycle commuter and managing editor of ACCESS Magazine) think they know why. In their essay Why Bicyclists Hate Stop Signs, they point to the excess energy required to make frequent stops and starts as the culprit:

With only 100 watts’ worth (compared to 100,000 watts generated by a 150-horsepower car engine), bicyclists must husband their power. Accelerating from stops is strenuous, particularly since most cyclists feel a compulsion to regain their former speed quickly. They also have to pedal hard to get the bike moving forward fast enough to avoid falling down while rapidly upshifting to get back up to speed.

For example, on a street with a stop sign every 300 feet, calculations predict that the average speed of a 150-pound rider putting out 100 watts of power will diminish by about forty percent. If the bicyclist wants to maintain her average speed of 12.5 mph while still coming to a complete stop at each sign, she has to increase her output power to almost 500 watts. This is well beyond the ability of all but the most fit cyclists.

Fajans and Curry put their theory to the test on California Street in Berkeley, one of the city’s designated “bicycle boulevards” that has 21 stop signs (!) over a 2.25 mile stretch. By comparing California Street with nearby Sacramento Street—which has few stop signs—they were able to measure a 30-39% difference in average speed due to the required frequent stopping and starting on California Street:

One of us (Joel Fajans) found that keeping exertion constant, he could ride on Sacramento at an average speed of 14.2 miles per hour without straining. At the same level of exertion, his speed fell to 10.9 mph on California if he stopped completely at every sign. Thus Sacramento was about 30 percent faster than California. By increasing his exertion to a fairly high level, his average speeds increased to 19 mph on Sacramento and 13.7 mph on California, so Sacramento was then 39 percent faster. While a drop of a few miles per hour may not seem like much to a car driver, think of it this way: the equivalent in a car would be a drop from 60 to 45 mph. Because the extra effort required on California is so frustrating, both physically and psychologically, many cyclists prefer Sacramento to California, despite safety concerns. They ride California, the official bike route, only when traffic on Sacramento gets too scary.

I observed this exact thing when I was in Berkeley last year. During the rush hour commute, I counted far more bicycles on the busier, more dangerous thoroughfares than on the designated bicycle boulevards. I can only imagine it’s because of the large number of stop signs on the quieter BBs.

Fajans and Curry suggest that the issue is mostly a result of car-centric traffic planners not truly understanding the needs of cyclists:

Car drivers say they are confused by the presence of bicycles on the road, and some wish the two-wheelers would just go away. Bicyclists know that cars cause most of their safety concerns . Traffic planners need to find ways to help bikes and cars coexist safely. A good place to begin is by taking the special concerns of bicyclists seriously, and not assuming that they will be served by a system designed for cars. Reducing the number of stop signs on designated bike routes would make bicycle commuting considerably more attractive to potential and current riders. Allowing bicyclists to treat stop signs as yield signs, as some states do, could solve the problems in a different way.

Perhaps cities should buy bikes for their traffic engineers and require that they ride them to work periodically. There ’s probably no better way for them to learn what it’s like to ride a bike in traffic than actually to experience its joys and hazards.

I have to agree with the authors; their call for more sophisticated traffic planning, that takes into account the true issues cyclists face on the road, is right on the money.

Read the full article (PDF) →

36 Responses to “Why Cyclists Hate Stop Signs”

  • Vik says:

    I routinely run through stop signs in my downtown ‘hood. I’m okay with this for a number of reasons:

    – go reasonably slowly 15-25kph
    – I slow down further at each stop sign and evaluate the situation
    – I don’t hesitate to stop or slow to a crawl if the situation warrants
    – I pose no risk to a car and only a small risk to a pedestrian
    – I’m cautious and take into account the impact of my behaviour on others

    When I want to ride fast I use the main streets and mix it up with traffic and deal with traffic signals. I generally don’t run traffic signals unless it’s 3am on a week night or 6am on Sunday morning. There is too much going on and the risk too great by doing something unexpected.

    I’d love better traffic planning that put more significance on cyclists. Who knows maybe high gas prices will lead in that direction. One can only hope.

    safe riding,


  • Thom says:

    I think Vik’s point is well-taken. Not all stop signs are created equal from a cyclist’s perspective. In my quiet residential neighborhood, I slow but don’t stop at all signs if I have clear sight lines and can see that no one is coming. However, if I’m riding in heavier traffic or I have a stop *light*, I will always stop, if for no other reason than to show all the drivers at the intersection that some bicyclists do obey the traffic laws. I don’t think it’s too much of a revelation to say that cyclists are trying to conserve energy by blowing stop signs, but all cyclists need to weigh the safety factor vs. the efficiency factor when they come to an intersection. The key is education so that cyclists can make the right choices at the right times.

  • todd says:

    apart from the simple physics, there’s history. bicycles, pedestrians, horsecarts, playing children, and streetcars shared the streets of many american cities for a couple decades *without stop signs or other traffic controls* before operators of noisy, speedy, lethal vehicles swept in and took over, killing and maiming themselves and other street users at such a rate that traffic controls were overlaid on the grid in response. their necessity is alien to the design of said cities, and to the safe operation of light, slow, small, agile vehicles like bicycles. the universal imposition of the law is testament to nothing but the radical monopoly of motor vehicles on our city streets, whose alien presence i cannot help but resent, in the same way the sioux indians might resent barbed wire cutting up the plains. sure: ignore at your peril, but question, remember, resist, overcome.

  • torrilin says:

    I stop. It is not fun. I do not *like* it. But stopping is the law, and I’ve had far too many run ins with cars speeding fast enough that I would have been hit if I hadn’t stopped. And I like not being hit, so I keep stopping.

    (also Alan, had you meant to change to a setup where the RSS feed only shows excerpts?)

  • Dolan Halbrook says:

    Yup, as anyone who has owned an underpowered, manual transmission car could tell you (or a bicycle), it’s all about conservation of momentum. Too bad we’re a nation of overpowered automatics.

    I commute up Lincoln St (one of Portland’s bike boulevards) daily and thankfully there are few stop signs or stoplights, and some of those are now roundabouts. Portland tends to ‘get it’, mostly.

    Neat to see a formal study done on this. Next stop: use it to make a convincing change in legislation, build more roundabouts, or change laws around stop signs.

  • MikeOnBike says:

    Hardly anybody (cyclist or motorist) stops for stop signs. For basically the same reasons. This isn’t really a bike-specific problem.

  • Cliff says:

    I stop all the time.
    I also agree with the study, it does take more energy to stop at the signs, when I was not commuting and doing many more training miles I would work harder on the rides, since all I can get to do lately is an 15 mile one way commute, the stop signs are the work.
    I make it a game to put a foot down at each and every sign, (even the D@&& one in the middle of the big hill)

  • Jon C says:

    Just my humble opinion, but while I agree with the efficiency and average speed aspects of ignoring stop signs, cyclists who disobey traffic rules which are accepted by the general public as improving safety aren’t exactly operating as good ambassadors for sharing the road with bicyclists.

    Anyone who has been on a bike for a moderate length of time is capable of a “rolling track stand” which maintains the appearance of stopping without putting a foot down on the pavement.

    I feel like I am a better ambassador for cycling and cyclists when I present myself as a fellow vehicle sharing the road than as one with special priveleges.

  • Dolan Halbrook says:

    The fact is, every stop sign and stop light is different. There are places where one can very safely blow through stop signs, and there are places where it is downright suicidal. Until traffic engineers (and later, the law) catch on to this, people will continue to blow stop signs and to a lesser degree, stoplights.

    Jon, your post, while I see the point, assumes the viewpoint of someone who has basically surrendered the roads to cars. This may be the fact, and where I agree with many of your points, i find it sort of sad. FWIW, I stop at pretty much everything as well, and have to be careful not to be rear ended by other cyclists. That said, I am far from content with the status quo.

  • Iain says:

    The joy in the UK is that very few junctions are actually controlled by STOP signs, here the majority are set as “Give Way” which are the norm unless the junction is deemed to have poor visibility. These are mostly Tee junction types and our cross roads are roughly a 50/50 mix of traffic lights (at which I stop) and roundabouts which again has the giveway rule applied.

    One of the issues with the 4 way intersection with a roundabout though is if a bike filters to the front the 2 ton of metal is usually looking in completely the wrong direction to see you and then correctly uses the whole lane which could lead to an accident.

  • Jon C says:

    @Dolan, you wrote: “Jon, your post, while I see the point, assumes the viewpoint of someone who has basically surrendered the roads to cars. This may be the fact, and where I agree with many of your points, i find it sort of sad.”

    Perhaps it is, though the automobile (in the petrol-power of today and whatever incarnation it is to take in the future) is here to stay and bicyclists are in the minority at the present. I would rather cycle defensively, if assertively, than have my 5 year-old grow up without a dad. If that’s a surrender of sorts, so be it.

    I don’t live in a big city with a healthy population with bike commuters and rarely see another cyclist on my 10 mile one-way commute. As such, I might be the only other bicycle any car on my commute shares the road with during the course of the day. Being a good ambassador to bicycling and bicyclists seems somehow prudent, given that.

  • arcadiagt5 says:

    Thanks for posting this, interesting read.

  • Louis says:

    I don’t agree. When I’m on my bike I obey ALL traffic rules. I would never brag about not doing so.

  • Dolan Halbrook says:

    @Louis. I don’t think anyone here is bragging about not obeying traffic rules by running stop signs. This is just a refreshingly honest discussion of why many (if not most) cyclists (not to mention drivers) don’t.

  • Croupier says:

    Of course I always used to peep the situation at an intersection before I’d coast through a stop sign, that was until a got two tickets in a row for doing just that… in the same day… at the same intersection… from the same cop.
    Now I always slow WAY down when I come to a stop sign. Am I a safer rider because of this? NO! I’m just a more “cop aware” rider. All I’m doing when I slow down is checking for fuzz. Dig on these statistics:

    -Number of Pedestrians Hit by Me at Intersections Before I Got Two Tickets in the Same Day: 0
    -Number of Pedestrians Hit by Me at Intersections After I Got Two Tickets in the Same Day: 4

  • Jeff says:

    I find it interesting that Idaho allows for bicycles to roll through stop signs and, after stopping, to ride through steady red lights (http://www3.state.id.us/cgi-bin/newidst?sctid=490070020.K). Thus, when riding along the quiet streets of my creepy suburban neighborhood, I will roll through the stop signs and justify my behavior by the fact that I’ve been to Idaho.

    I also sometimes muse on the fact that, due to the forward thinking of Idaho lawmakers (though I doubt it could be said in any other context), I can happily consider that forcing bicyclists to stop at signs and lights is not universally mandated in the United States.

  • Smudgemo says:

    I agree with stops being an energy drain, but as someone who rides Berkeley’s bike boulevards nearly every day, I’ll tell you one thing. I’ll take California over Sacramento any hour of the day.

    The boulevards may not be perfect, but they are a huge step in the right direction. They tend to discourage or prevent automobile traffic, diminish the me-first attitude of most drivers while on them and they give novices confidence to take to the road.

    Sure I ride plenty of non-boulevard streets for speed or convenience, but when I take my little kids for a ride to the farmer’s market, I take the boulevards.

  • Alan says:


    “Can I also vote for a return to *full* RSS feed instead of this new extract rubbish!”

    Like so many things regarding websites, it’s not that simple: there are multiple liabilities associated with publishing a full feed, not the least of which is content scraping, which can undermine a site’s hard-earned search engine placement. Here’s a good discussion on the subject.

    In any case, is it really that big a deal to ask readers to visit the site if they’re interested in a particular post? I try to make it a worthwhile visit by creating good looking pages and providing lots of photos. It’s just one click of the mouse afterall (I understand it’s an inconvenience for those accessing the site on a PDA, and apoligize to those folks).


  • Chris from DE says:

    Wow, great honest discussion folks. I admit I often roll through a stop sign on my commute under the following conditions:
    1) I’m in neighborhoods away from major traffic
    2) I slow down enough to check out the traffic coming up at the corner
    3) There are no cars coming from either direction (L or R)

    When I’m riding on the side of the road in heavy traffic, I tend to obey all traffic laws in order to make myself as predictable as possible to nearby car drivers. The last thing I want is for that driver to have no idea what my next move will be.

    I am also fond of “taking the lane” if I feel threatened. I’d rather have my ass right in the middle of the lane with traffic stacked up behind me until the light changes, than have people rushing past me on my left.

    I’m a recumbent rider and I also agree with Jon C.’s argument about being a good ambassador. I stick out as a ‘bent rider, and if I ride like a jerk, people are going to get the idea that cyclists feel they can ignore traffic rules. I really don’t want to perpetuate that idea.

    I also love the idea of having stop signs be yield signs for cyclists. I’ve never heard of that before.

    Chris from DE

  • Vik says:

    One question that always pops into my head when cyclists proclaim they always stop for a stop sign because it’s the law – so you never break any laws? For example in most jurisdictions riding on the sidewalk is illegal for adults – you never cruise 10 yards on a side walk to your destination – you always take the vehicle access to a business and walk your bike the rest of the way? When you drive your car you and the posted speed limit is 50mph you are never intentionally going 55mph or speeding up to 60mph to pass – both of which are not legal?

    The reason I ask is that I don’t know a single cyclist or car driver who doesn’t break at least one law on any given outing. In a car everyone I know and see on the roads is driving in excess of the speed limit – at least 5mph. So I wonder if people making these “…I always obey the law…” statements are for real or if they are just selectively obeying laws – which kind of takes the wind out of the sails of that argument.

    safe riding,

    Vik “the outlaw” Banerjee

  • Dolan Halbrook says:


    I was much more of a believer in taking the full lane until I got rear-ended by an inattentive driver. Luckily there was nobody in front of me, or I would have been squashed. Now I’m more a fan of filtering, or at least not riding in the middle of the lane, but on the outside edges.

  • Rob Mackenzie says:

    Having traffic planners who are more sensitive to the cycling perpective would be very welcome.

    Whenever we cycle and choose to break (or bend) any law or regulation I think we run at least three risks:
    – There is the “legalist” matter that we may get called to task on by whichever “authority” has been tasked with upholding the “rules”. We’re not usually a talking about a capital offense but this issue remains.

    – There is risk that we just get into bad habits… it can lead to taking less care than we should… that can lead to personal injury or harm to others.

    – Finally there is the risk to how we (the cyclists) are perceived. If we either often or occasionally hold ourselves above the laws we risk aiding and abetting the perception that cyclists are a “lawless” crew (and therefore have a reduced right to the roads). I suspect this is our largest risk.

    As some have pointed out, few of us are perfect — mea culpa. I just hope most of us try to obey most of the rules most of the time… it is in our common interest.

  • Darryl says:

    I am not a saint. I stop and I also roll through stops. It depends on the risks and visibility. Generally I slow down enough that I can put my foot down to stop on my recumbent or have my foot out of the toe clip on my upright bike. But at least I make an effort to slow to pay attention to what’s approaching. At busy intersections, I generally stop for safety and to be a “good” cyclist. I’ve also had to walk my bike across the intersection if need be.

    The main reason why I roll through an intersection is not only for “efficiency” but also you have to semi-dismount a bike and remount to start. That isn’t always gracefully done if you miss a pedal or not in the right gear; not to mention the effort to accelerate through an intersection. Stopping on a bike, therefore, is more awkward than stopping an automobile.

    The other issue is for those with clipless pedals. If I don’t have to unclip to put out my feet to stop, then I’ll keep moving. In city riding, I won’t wear my clipless footwear for safety reasons.
    Doing a track stand, as mentioned in a previous post, is harder to do, if not impossible, with freewheels than with fixies.

    Whatever method I use, the ultimate criteria is to avoid being roadkill first, being a good citizen second, Olympic cross-town commuter time-trial champion lastly.

  • Nate Briggs says:

    Hey Alan:

    Looks like you hit a nerve.

    Some excellent posts, above, but no one has mentioned the issue of visibility … in the sense of being able to see.

    Rolling up to a stop sign at about 7MPH, the bicyle allows me to see in a full 3-dimensional range – with full audio. So I can often feel confident with a “rolling stop”.

    A motorist is looking through the “slot” formed by a vehicles windows. And they are often not in a position to hear another motorist on a cross street. In order to be fully informed about how to proceed, a motorist needs to come to a more-or-less complete stop.

    With that said, I’ll agree with all the commentators that all of this is situational. Some cross streets are very quiet – and the stop is just perfunctory. Others are serious demands to stop, and take a look around.

  • Alan says:


    “Looks like you hit a nerve.”

    LOL.. I guess so. Maybe I’ll write a post on helmet use one of these days.. ;-)

  • Vik says:

    Alan….I’ll donate some gasoline for your helmet post…=-)


  • Alan says:


    Wow, if you think bicyclists and motorcyclists don’t like helmet laws, wait until they try to get that one through… LOL.

  • EcoVelo » Blog Archive » Stop and Roll (more on stop signs) says:

    […] a follow up to my post the other day [Why Bicyclists Hate Stop Signs], I wanted to point out that the SF Bay Area’s Metropolitan Transportation Commission is […]

  • Erik Sandblom says:

    Slightly off topic: traffic lights are not a safety device but a capacity device. You get more capacity by sending the cars in convoys.

    Traffic lights are arguably bad for safety, because a driver who gets a green light is likely to react with annoyance at anyone who gets in their way. “I have a green light, get out of my way”. Inciting that attitude is about the worst thing you can do for safety in traffic.

    A roundabout or yield sign is much better because it doesn’t implicitly absolve the car driver of responsibility. The green light does the opposite. It basically implies that anyone who gets in your way is an unshaven feminist chlorofyll communist ;-)

  • Jim says:

    Isn’t this sort of analogous to stealing a computer that you can’t afford, then arguing that it was the fault of the manufacturer for not having the forethought to make it affordable to you personally? Why you break a law is typically insignificant. It doesn’t mean you won’t continue doing it, but don’t act surprised when you get ticketed.

  • Dolan Halbrook says:


    That analogy falls down rather quickly.

    The roads are meant to be shared, and used, by drivers, cyclists, and pedestrians. They are designed by and for drivers primarily. They are funded by all of us, so should reflect the needs of all of us.

    A computer is a private resource, not a shared one, so there is a choice there. With roads one really has no choice, unless you choose to stay at home.

    Why people break the law is rather significant in the overall scheme of things, at least if you believe in democratic ideals. If certain laws are constantly flouted, you have to start to question the larger issue of with the law’s flouting is a symptom. Without that questioning, nothing ever changes for the better.

  • KU Cracks Down on Cyclists - Kansas Cycling News says:

    […] the other hand, there is some support for Idaho-style laws, where cyclists would be able to treat stop signs as yield signs, and […]

  • Opus the Poet says:

    I haven’t tried this approach, but in TX law there is a clause that says bicyclists must obey laws unless such laws “by their nature are not applicable to bicycles”. I would place stop signs installed for cheap traffic calming in the “not applicable” category. The problem is how to distinguish between the two? On the one hand you have stop signs installed for sound engineering reasons, because of limited visibility or pavement with reduced levels of traction in the intersection. Those should be obeyed by cyclists. On the other hand you have stop signs installed because they keep drivers from reaching dangerous velocities for too great a stretch of distance, i.e. traffic calming. Those should be ignored by cyclists. Unfortunately they are both shaped exactly the same and have exactly the same color and lettering. How can you tell the difference?

    The “quick and dirty” method would be to place a sign under the stop sign “Cyclists May Yield” or “bicycles may yield” for those stop signs that are for traffic calming. For a longer term solution there has to be a completely different shape sign, that means “stop” for cars and “yield” for cyclists. This accomplishes the traffic calming without inconveniencing those who are already calmed (traffic-wise I mean, there are a number of cyclists who are anything but calm).

  • Conan says:

    As a pedestrian, as I have walked on a crosswalk with a walk symbol and several times I have been almost knocked down by bicyclists pedalling through. I was recovering from knee surgery and one came on through forcing me to suddenly leap back (you can imagine how much that hurt), and the excuse of the cyclist was that she was emerging from behind a bus and didn’t see me.

    As a driver I have also come through intersections with a green light only to see a cyclist blow through in front of me. The coasting concept is a concern but I see many pedalling through. Not only that, why not extend the no stopping rule to cars also? Vision aside, what makes a bicyclist inherently better at making a decision as to when it is safe to break the law.

    While smaller, a bicycle is still a moving projectile with alot of momentum, I’ve been hit by one moving at speed in a place where no bicycling was allowed (a sidewalk fair).

    There may be more accidents caused by cars but maybe that’s because there are many more cars on the road and accidents with cars are more likely to be reported.

  • Cycles, economic and by- « Flight of the Moorglade says:

    […] trying to make up for the poor planning of their cities’ cycle ways. Every cyclist knows that annoyance of having to stop for a red light or a stop sign. Yes, we are officially vehicles, and must obey the road code, but the energy needs to restart […]

  • Same road, same rules? « just like riding a bike says:

    […] many blog posts on the subject of why bicyclists hate stop signs, such as these on Bicycle.com and Ecovelo, as well as the debate about who’s worse (motorists or cyclists) when it comes to stopping at […]

© 2011 EcoVelo™