Wide Vehicles – Narrow Lanes


NE2 asked:  Why is 14 feet the accepted minimum for a “substandard-width” lane.  Florida Statute 316.515(1) says that a vehicle may be 102 inches (8.5 feet) wide, not including safety devices (e.g. mirrors). I don’t know how far mirrors are allowed to stick out, but I would assume at least 6 inches on each side. With a 3 foot passing clearance, that leaves only 1.5 feet for the bike in a 14-foot lane, certainly not enough for safe operation.


You have correctly cited the applicable statute.

s. 316.515Maximum Width, Height, Length

(1) Width Limitation – The total outside width of any vehicle or the load thereon may not exceed 102 inches, exclusive of safety devices determined by the department to be necessary for the safe and efficient operation of motor vehicles.

Vehicles that are even wider may be encountered on the roadways.  It is not realistic to try to define a substandard-width lane based on the widest vehicle that could possibly be on the road.  Rather, it is defined based on the safety of the roadway users.

We must look at this question from the different perspectives of the cyclist and the overtaking driver.

A substandard width lane is defined in the bicycle regulations, and is one of the many conditions and circumstances that gives the cyclist the right to leave the right-most curb or edge of the roadway. I believe the intent of that provision is to allow a cyclist to control the lane and discourage unsafe passing within narrow lanes. Note that the statute does not specify the actual width of a substandard-width lane.

s.  316.2065 – Bicycle Regulations

(5)(a) 3. For the purposes of this subsection, a “substandard-width lane” is a lane too narrow for a bicycle and another vehicle to travel safely side by side within the lane.

Without regard to the width of the lane, the burden for safety when overtaking and passing a bicyclist lies entirely with the overtaking driver if the cyclist is otherwise obeying the law.  The driver must pass at a safe distance, and no less than 3 feet.

s.  316.083 – Overtaking and Passing A Vehicle

(1) …. The driver of a vehicle overtaking a bicycle or other nonmotorized vehicle must pass the bicycle or other nonmotorized vehicle at a safe distance of not less than 3 feet between the vehicle and the bicycle or other nonmotorized vehicle.

The driver of the overtaking vehicle must make the determination that it is safe before passing.  The driver of a Smart Car may be able to safely pass within a 12-foot wide lane if the cyclist is to the right.  The driver of the vehicle you describe in the question will have to wait until it is safe to change lanes to pass a cyclist in a lane that is 14 feet or even wider.

The width of 14 feet is derived from Florida Department of Transportation planning and design guidelines.  Note that they also indicate the 14 feet is the width that allows MOST motor vehicles to safely pass a cyclist while remaining within the lane.  Drivers of wider vehicles must change lanes to pass.

Plans Preparation Manual

Chapter 8 – Bicycle Facilities

Section 8.4.3 Wide Curb Lanes

Wide outside curb lanes are through lanes which provide a minimum of 14 feet in width.  This width allows most motor vehicles to pass cyclists within the travel lane, which is not possible in more typical 10-12 foot wide travel lanes.

Manual of Uniform Minimum Standards for Design, Construction and Maintenance for Streets and Highways (Florida Greenbook)

Chapter 9 – Bicycle Facilities

B.3  Curb Lanes

Fourteen feet is the recommended lane width for shared use in a wide curb lane, and is the minimum width that will allow passenger cars to safely pass bicyclists within a single lane.

More detail of the various rights and responsibilities of roadway users can be found in the post on Substandard-Width Lanes.

Posted in Ask Geo, Impeding Traffic Tagged with: , , ,
5 comments on “Wide Vehicles – Narrow Lanes
  1. NE2 says:

    I guess I should have directly asked what I was implying: Does one have to ride to the far right side of a 14-foot lane? The statute says “a bicycle and another vehicle”, not “a bicycle and a passenger car”, and 14 feet is not wide enough for a bicycle and a standard truck.

    I regularly ride near the center of a 14-foot outside lane on a suburban four-lane road with speed limit 45 mph. There is little enough traffic that my riding does not cause delays of more than a few seconds for other drivers (when traffic is heavy I’ll use the sidewalk or alternate routes). I’m concerned that despite this I’m at risk of being ticketed by a disgruntled cop (I’ve had one interaction on a nearby road with narrower lanes with a supposed cop, who told me to get on the sidewalk: http://commuteorlando.com/forum/index.php?topic=413.0).

  2. Cecil Powell says:

    Reading this post brings back memories of planning and designing roadways for the FDOT. However, I am curious about the percentage of Florida auto drivers who may be knowledgeable of these facts and many others. They are tested once when they receive their initial license, and never again, if they lawfully maintain them. While a Real Estate agent must take a 14 hour continuing ed course every two years, along with most others licensed under DBPR. Wouldn’t it be an “excellent” idea to make vehicle drivers do the same? This way they could be taught new rules of the road, be tested again for compency, and the State could legitimately raise needed roadway funding. Another thought: If the FBA instigated this new law, We could probably direct some of the funding into the construction of “safe” bicycle lanes!

  3. Geo says:

    Regarding the sidewalk, it seems you are fully aware that cyclists are not required to use them, but if not, see:


    The statute says a substandard-width lane “is a lane too narrow for a bicycle and another vehicle to travel safely side by side within the lane.”

    Generally, cyclists must stay as close as practicable to the right-hand curb or edge of the roadway except under any of the following situations:
    3. When reasonably necessary to avoid any condition, including, …. or substandard-width lane, that makes it unsafe to continue along the right-hand curb or edge.

    If a 15-foot wide “wide load” truck is overtaking a cyclist in a 14-foot lane, it is obvious that the conditions are met to permit the cyclist to take the lane. It is also obvious that the truck driver must change lanes to pass, no matter where the cyclist is in the lane.

    The 14-foot general width for MOST vehicles would seem to apply to most, but not all, circumstances. It has been tested in in court three jurisdictions and has been upheld when applied to 12-foot lanes.

    There is no Court of Appeal case law to support these cases, so they will remain uncertain until that happens. I believe if you were able to document that the majority of traffic on the 14-foot lane you mention is “wide vehicles”, then you should be able to justify it as generally one of the situations considered an “unsafe condition” in (5)(a) 3 of the Bicycle Regulations. However, there is no certainty about the enforcement of narrow lane cases, or even their resolution in court, since there seems to be considerable misunderstanding about cyclists in substandard-width lanes. See:


    • NE2 says:

      Re: sidewalk, yep. Given the extremely low number of intersections (essentially 3 driveways in 2 miles) I concede that my very slight decrease in convenience for slowing down for these conflict points (and other sidewalk users) is not worth causing significant inconvenience to other road users when traffic is heavy.

      So is it your opinion that on a road with 12-foot lanes that sees a majority of vehicles narrower than normal cars, one may be required to ride to the far right, even though a normal car may come along at any time?

      Also, have there been any cases dealing with using the full lane at a time when traffic was minimally impeded?

  4. geo says:

    This is only speculation, but I think not, since there seems to be reasonable support for the 14 foot MOST vehicles idea. It is pretty well documented by FDOT language. I only mention the wide vehicle situation in case someone could document the traffic in a particular area. Not easy to do, but if it is a problem, it might be worthwhile.

    There have not been many cases, which is a problem in itself. None have reached the Court of Appeal to give us case law. In my experience, cyclists who are cited for these violations usually just pay the fine and don’t properly challenge it, or choose the represent themselves. The cost of an attorney is usually the deterrent. We have had a few that were successful though, and the motions to dismiss are available for use by others.

Leave a Reply