2Abreast & Sharrows

We received another great question from a local bike educator about riding 2 abreast and sharrows! 

(Photo used with permission by the folks over at Bike Fort Collins -check out their cool test  here ).

(Photo used with permission by the folks over at Bike Fort Collins -check out their cool test here).


"The issue was a motorist had an interaction with two people who were riding double wide on a road with two lanes going in the same direction.  The cyclists were in the right-most lane and there was a sharrow on the roadway in the lane where the cyclists were riding two abreast.  The motorist pulled over to have a discussion with the people on bikes because the motorist thought it was against the law for the cyclists to ride two abreast on the roadway (they were impeding traffic in one lane).  The cyclists said to the motorist that their interpretation of the law was that it was legal for them to ride two abreast and impede traffic for the narrow stretch because a sharrow was present.  In the area where the cyclists were riding, an individual cyclist would likely need to take the lane regardless.  Does riding two abreast in that scenario constitute something lawful or illegal?  An individual cyclist would likely need to impede traffic for a period in order to pass through the area that was too narrow to share with a motor vehicle.  In addition,  does the presence of the sharrow have any legal implications?  Does it indicate that riding two abreast for a stretch of road is legal?"


First, please refer to my previous blog post about riding 2abreast, generally.  

Second, let's talk about what a sharrow is and what it means! 

Wikipedia defines a shared-lane marking or sharrow as a street marking installed at locations in Australia, Canada, Spain, or the United States. This marking is placed in the travel lane to indicate where people should preferably cycle.

The US Manual on Uniform Traffic Control Devices says shared-lane markings may be used to:

A. Assist cyclists with lateral positioning in a shared lane with on-street parallel parking in order to reduce the chance of a bicyclist impacting the open door of a parked vehicle;

B. Assist cyclists with lateral positioning in lanes that are too narrow for a motor vehicle and a bicycle to travel side by side within the same traffic lane;

C. Alert motorists of the lateral location bicyclists are likely to occupy within the traveled way;

D. Encourage safe passing of bicyclists by motorists; and

E. Reduce the incidence of wrong-way bicycling.

See also, NACTO's discussion of when and where sharrows should be used.  (NACTO is a non-profit association that represents large cities on transportation issues of local, regional and national significance).

Third- so does the presence of a SHARROW indicate cyclists may ride 2 abreast, if it (as (b) above indicates), demonstrates that the lane is too narrow to share with a car? 

Short answer: no.  A SHARROW is painted on the roadway - but it is not a separate facility or "built for the exclusive use of bicycles" as a bike lane or bike path would be.

C.R.S. 42-4-1412 refresher:

(6)(a) Persons riding bicycles or electrical assisted bicycles upon a roadway shall not ride more than two abreast except on paths or parts of roadways set aside for the exclusive use of bicycles.

 (b) Persons riding bicycles or electrical assisted bicycles two abreast shall not impede the normal and reasonable movement of traffic and, on a laned roadway, shall ride within a single lane.

 So then -other than alerting motorists that the roadway is too narrow to share and that they may encounter a bicyclist riding in the center of the lane, what else is important to know about sharrows? 

Well -they change the liability analysis on the part of the city or municipality that installed them.  (See Boub V. Township of Wayne for further discussion on the issue of "permitted/intended users of the road" discussion.


Although a sharrow serves to alert motorists that a cyclist may be in the middle of the traffic lane (basically just painting the law that a lane too narrow to share means the cyclist may take the lane), it does not change the analysis of WHEN cyclists may ride 2-abreast in a roadway in Colorado.   

With regard to the specific question posed above, it is unclear whether the 2 riders were "impeding traffic" or not -we don't have enough info to answer that.  If there was just one motorist behind them who was inconvenienced, the answer would likely be no, they were not impeding traffic.