The Online Voice of the Bicycle Alliance of Washington

Tuesday, February 1, 2011

Gravity, Bike Lanes and the Limits of Vehicular Cycling

Today's post with accompanying photos was submitted by Mark Davison. Mark has been cycling in Seattle since 1988, both for exercise and for practical transportation. During a 9 year period in the 70’s he was carless and used a bicycle as his primary mode of transportation, which has made him a stalwart defender of cyclists’ rights.

Like any political activity these days, bicycle advocacy appears to be split apart by warring dogmatic points of view. 

At one end of the spectrum, the Vehicular Cycling camp holds that "bicyclists fare best when they act, and are treated in return, as drivers of vehicles, with the same rights and responsibilities that motorists have.”  This point of view is worked out in full in the book Effective Cycling by John Forester. The essential idea is that cyclists must be trained to ride in--rather than beside--traffic, and that to avoid collisions at intersections they must learn to choose both the appropriate lane and position within that lane. Safe lane position is obtained by carefully merging into traffic lanes as required. From this point of view, cyclists should never be legally required to remain in bike lanes, as this will prevent the correct lane positioning.

Although Forester's Effective Cycling curriculum is no longer used by the League of American Bicyclists, similar ideas on lane positioning are included in the LAB Smart Cycling curriculum. An excellent video demonstrating the techniques from the cyclist's point of view can be found at

A corollary of the Vehicular Cycling point of view is that money spent on separated bicycling facilities is almost certainly money wasted, condemning cyclists to frequent collisions at intersections.

At the other end of the spectrum, the Sheltered Cycling camp holds that normal citizens can only be enticed into cycling if they are provided with separated facilities, which will allow them to overcome their fears (justified or not) of having cars collide with them from behind. Separate facilities can be either bike lanes striped on the pavement, or preferably cycle tracks or cycle paths that are physically separated from the roadway. Collision rates from interference with cars at intersections may be higher than in the vehicular approach, but the sense of security provided by the separated facilities will attract so many new cyclists that the overall rate of collisions will be lower because motorists will become more aware of cyclists. Motorists who comment on the web on cycling issues are often attracted to this theory because it gets cyclists out of the way.
This point of view reaches its purest form in the Copenhagen school, as is discussed in great length at . The site's author, Mikael Colville-Andersen, also advocates for cycling in ordinary clothes without helmets so that prospective cyclists will identify more with cycling as an activity. 

The political corollary of the Sheltered Cycling point of view is that all funds for bicycling facilities should be spent on lanes, tracks and paths that separate cyclists from the roadway. Use of sharrows is considered at best evil, at worst an invitation to chaos.

How do these two schools of thought play out in the actual behavior of Seattle cyclists? I don't have a definitive answer, but one recent, rare and deliciously sunny winter day in downtown Seattle I walked up Pine Street headed east, and watched cyclists interacting with traffic.
What I found is that each point of view fails because it doesn't allow for the gravity of the situation.

Going uphill, cyclists struggle to overcome the unavoidable retarding force of gravity. Traveling little faster than a walking pace, they seem content (or perhaps resigned) to stay in the bike path even if this puts them in the "door zone" where they might easily collide with an opening car door. Merging into the traffic lane when flowing traffic is present is impossible, given the speed differential.  Left turns are made by crossing the intersection, stopping on the far side and waiting for the light. Left and right hooks are prevented by carefully timing  passage through the intersection, or by dismounting and crossing as a pedestrian. I witnessed one cyclist simply riding up the sidewalk. He had very low gears and was proceeding at a slow walking pace, expertly riding around lamp posts and pedestrians.

Going downhill, cyclists were liberated by the helping hand of gravity. On many of Seattle's hills it is easy for a cyclist of no particular athletic strength to maintain 25 or 30 mph. At these speeds it is practically suicidal to remain in a bike lane that is striped too close to the parked cars. You see the cyclists swooping down the hills, claiming the lane, merging left to make left turns, just as the Vehicular Cyclists would have them do. Evidently Seattle cyclists’ fear of being killed or maimed from striking a car door that is opened suddenly in front of them conquers their desire to be protected from the cars, and they are liberated from the Copenhagen conventions.

On level roads I didn't see any consistent behavior.  When traffic was light cyclists stayed in the middle of the lane, especially when there was another lane in the same direction so cars could get around.
So here's my summary.  Going uphill, gravity slows down cyclists so much that full vehicular cycling is impossible. Going downhill, the natural speed of a bicycle is high enough that vehicular cycling is possible for almost all cyclists, and will be preferable to either striking an opening car door at high speeds, or creeping along in the bike path at 5 mph, riding your brakes the whole way down. On the level, it depends on how fast the cyclist can go relative to the density and speed of the motorized traffic. My own experience from cycling in Seattle is that most Seattle bike commuters maintain between 15 to 18 mph on the level. This is far too fast to cycle in the door zone, but often too slow for impatient motorists who want to speed from one light to the next so they can spend more time waiting in line.

The Seattle Department of Transportation seems to be coming to grips with the immutable force of gravity. In the recent road diet applied to Stone Way, the steep sections have bike lane markings going uphill, and sharrows on the downhill side.

Unfortunately this means that the dogmatic purists can only go one way-- the chic ladies on their fat tired Dutch bikes will be grinding up the hill in the bike lane, and the lycra clad vehicular curmudgeons will be flying downhill over the sharrows.  

The rest of us will have to operate both ways and free ourselves from the bonds of dogma as we submit to the dictates of gravity.


  1. I think the middle path was written some years ago- it's called the Revised Code of Washington. A cyclist traveling at less than the speed of traffic shall stay as far to the right as is safe, except when preparing to make or making turns,a cyclist at the speed of traffic may use the centre of the lane.
    This really works, you use the what ever part of the lane you need to depending on your speed, your safety, or your direction of travel. Pulling up to a stop sign, when traffic slows to your speed, you can merge in (you are at the speed of traffic) and hold your position at a stop, climbing a hill, off to the side if it's wide enough, or taking the lane for your safety if it isn't wide enough to share. And no, you are not impeeding traffic, you're going as fast as a cyclist can go, and you may take the lane for your safety, totally legal.
    Riding at speed, the safest is to ride the middle of the lane, just like the vehicle operator that the law says you are.
    I'd like to see infastructure that supports this concept, wide areas for climbing, sharrowed downhills, and a motorist and cyclist education program that would teach all road users the how and why of using the roads.

  2. Well said, Leo. I'm still not all that sure about sharrows, though. For them to be effective, drivers will have to notice them, understand what they mean, and modify their behavior accordingly. I'd like to see a study on what percent of drivers make it through each of those criteria. I'm afraid it would be pretty low. And if they're not effective, they may give cyclists some false security.

  3. I mention sharrows but... you really don't need them. If you are in the lane , at speed, or in the lane beciase it isn't safe for you to be on the right, or are preparing to mak or making turns, then you are riding within the law. I only see the need for sharrows as a means to inform the motorist that bicycle may be in the road legaly. Thinking that a education program would eliminate the need and cost to paint those on the road.

  4. I'm impressed by how well the RCW works. Riding through a roundabout (I like those), the law says you may take the lane when preparing to making or making turning motions, the safest place in a roundabout is to control the lane centre to prevent right turning drivers from turning into you, and to be visible to people entering the roundabout, and to give you room to manuver for your safety in the lane. I think when the law was written , Washington didn't have any roundabouts.
    We have very good laws. What is needed is education for motorist who don't understand why we use the centre of the lane, Law Enforcement that understands and enforces our use of the lane, and education for cyclists to understand how to use the law.

  5. This false dichotomy of vehikular cyklists versus infrastructuralists is a gross mischaracterization of sensible planning for roadway bicycling traffic using the omnibus of design recommendations from the federal highway administration.

    Planning for roadway bicycle traffic will necessarily incorporate a variety of infrastructure designs and it is widely recognized that cities with bikelanes continue to have the majority of the city streets plain and unadorned. Very few streets actually need or get bicycle specific improvements in US cities that put in bikeways and implement bike master plans.

    It would be hard to find a bicyclist that thought high speed, high volume roads with nonexistant or narrow shoulders are preferable to the same road with a wide, improved shoulder.

    the argument the author tries to use as a picture of segregation versus vehicular cyclist fails, as both sides of stoneway is a bikeway. The street has elements of both bikelanes and shared lane use, there is a pocket bikelane downhill at 40th and stoneway.

    There are two types of bicyclists: those that wisely believe in better planning for roadway bicycle traffic and the fringe ones who postulate no planning is somehow a better option.

    the false dichotomy of the extreme vehikular cyklists verus those that believe there should be better planning for bicycle traffic ignores all the shades of gray in realistic opinions about bicycling infrastructure.

  6. There is nothing bad about going at walking pace uphill on a bike in the traffic lane. If drivers want to pass, they can pass, just as they pass any other slow-moving vehicle. Your article seems to suggest that a bike with the right of way should cede it to the car behind (presumably because you falsely believe that a motorist has more rights to the road in front of the cyclist than the cyclist does). This doesn't reflect current law, nor is it safe to go weaving in and out of bike lanes based on what one's kinetic energy state is.

    The fact is, moving into a bike lane on a tough uphill climb does not get the cyclist to his destination any faster. All it does is make his movements less predictable to those drivers around him.

  7. I was going to ask why the false dichotomy, but Beck the Biker beat me to it. Thanks for the article, at any rate. Grist for the mill.

  8. In response to "Beery" who said:
    "There is nothing bad about going at walking pace uphill on a bike in the traffic lane. If drivers want to pass, they can pass, just as they pass any other slow-moving vehicle."

    It seems to me it's simple common courtesy (which is less and less common these days) to avoid inconveniencing other people unnecessarily. If I'm going 5 mph uphill and cars behind me can legally to many times faster, I'd feel like a jerk to hog the lane when I could safely ride to the right and let them pass. This is especially true on a busy street with lots of traffic coming the other way, making it impossible for cars to use the other lane to pass. Why not "Do unto others as you would have them do to you." ?

  9. The best solution: Remove parking entirely from the sides of major bike routes. Eugene, Oregon has done this. Result: Bicyclist may travel at whatever comfortable speed he likes without any chance of a car door opening. Neither does he need to keep up with the speed of cars! Left and right turns can still be troublesome. However, car drivers will NOT develop road rage because bicyclists will NOT be slowing them down. Politicians must have the courage TO TAKE AWAY PARKING.

  10. Come on. There is enough knowledge out there about how to build good, safe bike infrastructure. And it is not running a bike lane where you could be doored, forcing the cyclist to choose between that risk and the risk of competing with the iron chariots on their turf.

  11. @ John Lindstrom

    Obviously very different political situations in Eugene vs. say, Seattle or Bellevue. Businesses (and the public) would never go for eliminating on-street parking. Although, this is not to say it can't/won't happen very incrementally over time as businesses come to recognize that providing better access to bicyclists could actually increase business.