Bicycle drivers “own” the road to the same extent as motorists. The driver in front is supposed to have the right-of-way and lane control whether the driver is on a bicycle or another vehicle. Photo courtesy of Karen Karabell, St. Louis.
According to the Manual on Uniform Traffic Control Devices (MUTCD) the
SHARE THE ROAD plaque is supposed to warn motorists that bicyclists are traveling along the highway. So why doesn’t it say that or something similar? Why the ambiguous SHARE THE ROAD message?
The W11-1 bicycle icon warning sign as a stand alone sign is sufficient to alert motorists to downstream bicyclists. Adding the W16-1 SHARE THE ROAD plaque results in a message that can be used and mis-interpreted the opposite of its officially intended meaning. If a supplemental plaque is to be used, there are better options than SHARE THE ROAD to warn motorists of bicycle users ahead.

The authorities in California show their hand with this installation with a regulatory sign instructing bicyclists to RIDE SINGLE FILE. Photo courtesy of Lee V. Milon and Davis Bike Club.
The SHARE THE ROAD plaque is sometimes mis-interpreted by both motorists and bicyclists to mean that bicycle users are to SHARE THE LANE by riding far right. The plaque implies the falsehood that motorists control the lane, and can choose to share some of it with bicycle users.
The SHARE THE ROAD plaque is typically misplaced on narrow roads whose lanes are not amenable for sharing side-by-side. It does not fulfill 3 of the 5 requirements of a traffic control device as described in the MUTCD.
In contrast, the new R4-11 BICYCLES MAY USE FULL LANE regulatory sign is unambiguous. It is the evolution, and supersedes the SHARE THE ROAD warning sign as the preferable message to motorists and bicyclists. A CHANGE LANES TO PASS supplemental plaque would provide added direction.
The Share The Road Sign paper discusses this combination sign, and provides a rationale for dispensing with the “SHARE THE ROAD” placard.

February 9, 2012 at 12:15 pm
My thoughts are aptly expressed in “Share the Road, STINKS”
http://www.ohiobikelawyer.com/uncategorized/2010/09/share-the-road-stinks/
You hit it on the head in that the signs are misinterpreted. However, around here they are used on the big, wide bike thoroughfares and not, generally, on those tight curvy roads where bikes are permitted but not really tolerated by motorists… they should be called “Bikes Might Be In The Way” signs for motorists…
February 9, 2012 at 1:18 pm
I always thought the sign should say “Expect Bicycle Traffic” as a reminder to be vigilant (which they should be at all times anyway). Of course, to follow up on Steve’s comment, that might be interpreted as “Expect Bicycles To Be In The Way”.
February 9, 2012 at 2:27 pm
I like Change Lanes to Pass – the current sign is good on intent but poor on specifics, in my view. In NJ there’s a law that applies when encountering horses on the roadway, which requires slowing to 25mph and following the horseperson’s hand signals for when to pass. I like that approach better than the current ambiguity, too, and believe it could be adopted/adapted for bicyclists.
February 10, 2012 at 3:37 am
“Narrow Lane”
February 10, 2012 at 5:27 pm
All good thoughts. Thanks.
July 19, 2012 at 10:34 am
STR signs are wasted paint, no one has to share anything if they don’t want to, not sharing is not actionable
Use caution, Bicycles on the Road (or similar), not using “caution” IS actionable…………….its called negligence
July 20, 2012 at 10:30 am
Please note that the “Ride Single File” sign in the photo above was apparently installed by California’s Solano County Public Works Dept. It’s a local anomaly that we hope to get removed soon. It’s not a sign for statewide use.
July 20, 2012 at 7:57 pm
Thanks David. Irrespective of the installing agency, the “Ride Single File” paired with the STR sign exemplifies the misinterpretation and misuse of the STR sign.
October 1, 2012 at 12:54 pm
I am going to mount a milk crate on top of my rear bike rack. I am going to bolt a reflective R4-11 “BIKE MAY USE FULL LANE” sign to the milk crate. The standard sign is 30”, so I will need to special order a smaller size. It is going to be glorious!
October 1, 2012 at 3:02 pm
That’ll be fabulous.
Regards, Wayne