An image of a sharrow from the Cornell Local Roads Program.

Sharrow is a fairly new term for transportation planners in the United States. The word sharrow refers to an arrow found within a travel lane to remind drivers to “share the road.” Drivers in most places need this reminder. Cyclists are allowed to travel with the flow of traffic on city streets unless otherwise stated.
The bicycle, as a form of transportation, continues to increase across the world. Many people change their mobility habits for reasons of gasoline costs and the desire to combine exercise and daily commutes. This provides the need to incorporate bicycle lanes, trails, and even bicycle boulevards into our planning processes.
The sharrow is one of the major components to the bicycle infrastructure equation, as referenced in the previous blog post Bicycle Infrastructure. I am making the argument that the sharrow is almost utilized too much. Often times, the sharrow is added to a street that would otherwise be better suited for a bicycle lane. I have also asked the following question that I would like to pose to my readers: “By designating multiple streets in a community as the need to ‘share the road’, are we therefore telling drivers that on the unmarked streets, that they do not have to ‘share the road‘?”
Please don’t misread this post believing that I think that sharrows are a bad idea. That is certainly not the case. I believe in sharrows and think that they are a great addition to bicycle mobility. However, they cannot be used as a substitute for bicycle lanes.
I have seen the sharrow used as justification for making travel lanes wider than they need to be on streets that not appropriate, nor safe, for bicycle travel. To understand the flaw in this justification, one must first understand that the wider the space for typical vehicular travel, the more dangerous that it is. If the street requires widening for bicycle mobility, the bicycle lane is a much greater option.
The sharrow is intended to be used on streets with target vehicular travel speeds of 20 to 25 miles per hour. For more information regarding the use of sharrows, there is a valuable tool available as a module to the SmartCode titled The Bicycling Module. The Bicycling SmartCode Module was authored by Mike Lydon with Zachary Adelson and Tony Garcia. It can downloaded free at