Category Archives: Bike lanes

Avoiding the left cross

This post isn’t about pointing the finger of blame. If that is to your taste, you can find endorsement of that position in many of the comments on the video on YouTube. But I think that we would rather avoid crashes in the first place, so this post is about avoiding crashes.

The cyclist could have prevented this crash. He missed three cues that it was about to happen. The motorist missed one cue.

Briefly at 0:09 through 0:10 in the video, the car which was about to turn left is visible with its left-turn signal on. The cyclist’s camera saw the car and so the cyclist also could have seen it and the motorist could have seen the cyclist, but neither was looking at/for the other. The car slowed (note increasing gap between it and the SUV ahead of it). The minivan which the cyclist was passing on the right also slowed, leaving a gap for the car to turn left into the driveway. These were additional cues which the cyclist might have heeded. Following the brief interval when the cyclist and motorist might have noticed each other, the minivan screened the cyclist’s and motorist’s view of one another until too late for either to prevent the collision.

How might cyclists avoid crashes like this? While it is tempting to maintain speed in a bike lane when motor traffic to the left is slow or stopped, do not expect that the bike lane somehow makes you immune to incidents like this. Do not pass on the right any faster than would allow you to avoid a vehicle or pedestrian crossing in front of the vehicle to your left. If you can safely pass motor vehicles on the left (though not here on this two-lane road), do that instead.

Say what?

Click on the photo for a larger view. Your comments are welcome.

Cambridge Street at Sudbury Street, Boston, July 25, 2017

Cambridge Street at Sudbury Street, Boston, July 25, 2017

The location as of September, 2016:

July, 2015

October, 2014

September, 2013

Alice Swanson fatality, a right hook

Here is the intersection in Washington, DC, where cyclist Alice Swanson was killed by a right-turning garbage truck.

The Street View is from 2009, as close as Google gets to the year of the crash (2008). The big cross street is Connecticut Avenue. The little one before it is 20th Street NW. My recollection is that the garbage truck turned right into 20th Street, and Swanson probably assumed she could pass it safely because it would turn right onto Connecticut Avenue and the traffic signal was red. If you open the Street View in Google Maps and click on the clock at the upper left, you can go to Street Views from different times and see the intersection without a bike lane (2007) and with green paint (2014). The dashed bike lane stripes indicate that motorists are supposed to merge into the bike lane, but many do not and it may not even be possible with a large truck. Note also that parking extends close to the intersection — the last 20 feet or so are no parking, with a fire hydrant.

Boston expert design

Here’s a video of the intersection of Commonwealth Avenue and St. Mary Street, Boston, Massachusetts, USA, an example of the design expertise which earns Boston its place with the League of American Bicyclists as a Bicycle Friendly City.

The video is from 2013. As of 2016, one change has been made: the zigzag in the bike lane has been replaced by a diagonal transition.

The idea that cyclists should turn across in front of multiple lines of motor vehicles to change lane position is not unique to this location. Here’s another example, and it is by no means the only other one:

I have a blog post in connection with that video too.

Ogden, Utah skateboarder stop

There’s plenty of confusion to go around here.

Deputy: “I don’t care, you’re right in the middle of the road.” No, the boarder was on the shoulder, at least in the part of the video the TV station broadcast.

Was that legal? Bicycling is allowed on shoulders in many states. I couldn’t find anything on that on the Utah legislative site section on bicycles,

But the man was on a skateboard, not a bicycle. Under Utah law, the skateboard is defined as a vehicle, last definition here: and so, under the law, the skateboarder should have been in the travel lane, not on the shoulder or a sidewalk, if any, as little sense as that may make.

So, the officer’s charge was false. If the boarder were defined as a pedestrian, then shoulder use in the absence of a sidewalk would be legal if the boarder was traveling opposite the direction of traffic (he wasn’t), — not that this is sensible when it would have required crossing to the far side of a multi-lane road.…/Title41/Chapter6A/41-6a-S1009.html.

There is a sidewalk, as shown in Google Earth and Street View images.

The TV station video is edited at 00:25. It doesn’t show the entire conversation between the deputy and the boarder before the boarder attempted to flee — so we don’t know about an opportunity to comply. Other question is how the boarder could comply if there was nowhere to go except up and down a road bordered by vegetation. The deputy ran after the boarder and attempted to stop him. Probably better to let him go. The boarder fought the deputy, violently. Not smart at all.

Change lanes in a roundabout?

Ohio cyclist Patricia Kovacs posted an e-mail asking some questions about roundabouts:

Ohio engineers are telling us to use the inner lane for left turns and U turns. Both the FHWA [Federal Highway Administration] and videos available on our local MPO [metropolitan planning organization] website say this. I shared this when we asked for updates to Ohio Street Smarts. If the FHWA and MORPC [Mid-Ohio Regional Planning Commission] are wrong, then we need to fix it.

Would you review the 8 minute video on the MORPC website and let me know what I should do? If it’s wrong, I need to ask them to update it. This video was made in Washington and Ohio reused it.

Looking further into the problem, I see a related practical issue with two-lane roundabouts, that the distance between an entrance and the next exit may be inadequate for a lane change. The larger the roundabout, the longer the distance in which to change lanes, but also the higher the speed which vehicles can maintain and so, the longer distance required. I’m not sure how this all works out as a practical matter. Certainly, turning right from the left-hand lane when through traffic is permitted in the right-hand lane is incorrect under the UVC [Uniform Vehicle Code], and results in an obvious conflict and collision potential, but I can also envision a conflict where a driver entering the roundabout does not expect a driver approaching in the inside lane of the roundabout to be merging into the outside lane.

All in all, the safety record of roundabouts is reported as good (though not as good for bicyclists and pedestrians), but I’m wondering to what extent the issues have been subjected to analysis and research. When I look online, I see a lot of roundabout *promotion* as opposed to roundabout *study*. Perhaps we might take off our UVC hats, put on our NCUTCD [National Committee on Uniform Traffic-Control devices] hats, and propose research?

Thanks, Patricia.

This post was getting long, so I’ve placed detailed comments on the Ohio video, and embedded the video, in another post. I’m also working on an additional post giving more examples, and I’ll announce it here when it is ready.

Here are some stills from the video showing the conflict between through traffic in the outer lane and exiting traffic in the inner lane.

First, the path for through traffic:

Path for through traffic in a roundabout

Path for through traffic in a roundabout

Next, the path for left-turning traffic:

Path for left-turning traffic in a roundabout

Path for left-turning traffic in a roundabout

Now, let’s give that picture a half-turn so the left-turning traffic is entering from the top and exiting from the right:

traffic in a roundabout, image rotated 180 degrees

Path for left-turning traffic in a roundabout, image rotated 180 degrees

And combining the two images, here is what we get:

Conflict between through traffic and exiting left-turn traffic

Conflict between through traffic and exiting left-turn traffic

The image below is from the Manual on Uniform Traffic Control Devices, and shows similar but not identical lane use. The arrows in the entry roadways direct through traffic to use either lane.

FHWA diagram of a roundabout with lane-use arrows.

FHWA diagram of a roundabout with lane-use arrows.

Drivers are supposed to use their turn signals to indicate that they are to exit from the inner lane — but drivers often forget to use their signals. Safe practice for a driver entering a roundabout, then, is to wait until no traffic is approaching in either lane, even if only entering the outer lane.

A fundamental conceptual issue here is whether the roundabout is to be regarded as a single intersection, or as a series of T intersections wrapped into a circle. To my way of thinking, any circular intersection functions as a series of T intersections, though it functions as a single intersection in relation to the streets which connect to it. Changing lanes inside an intersection is generally prohibited under the traffic law, and so, if a roundabout is regarded as a single intersection, we get the conflicts I’ve described.

Sometimes, dashed lines are used to indicate paths in an intersection, when vehicles coming from a different direction may cross the dashed lines after yielding right of way or on a different signal phase. More commonly, a dashed line  indicates that a driver may change lanes starting from either side. The dashed lines in a two-lane roundabout look as though they serve the second of these purposes, though they in fact serve the first. These are shorter dashed lines than generally are used to indicate that lane changes are legal, but most drivers don’t understand the difference.

That leads to confusion. If you think of the roundabout as a single intersection, changing from the inside to the outside lane is illegal anywhere. If you think of the roundabout as a series of T intersections, changing lanes should occur between the entries and exits, not opposite them –though there is also the problem which Patricia mentioned, that a small two-lane roundabout may not have much length between an entry roadway and the next exit roadway to allow for a lane change. That is, however, much less of a problem for bicyclists than for operators of wider and longer vehicles. It would be hard to construct a two-lane roundabout small enough to prevent bicyclists from changing lanes.

My practice when cycling in conventional two-lane traffic circles — and there are many in the Boston, Massachusetts area where I live — is to

  • enter from the lane which best leads to my position on the circular roadway — either the right or left lane of a two-lane entry;
  • stay in the outer lane if leaving at the first exit;
  • control the inner lane if continuing past the first exit;
  • change back to the left tire track in the outer lane to prepare to exit.

That way, I avoid conflict with entering and exiting traffic in the outer lane, and I am making my lane change to the right in the slow traffic of the circular roadway rather than on the straightaway following it. This is what I have found to make my interactions with motorists work most smoothly. Why should a bicyclist’s conduct in a roundabout be different?

It is usual to be able to turn right into the rightmost lane of a multi-lane rodway while raffic is approaching in the next lane. I don’t know of any other examples in road design or traffic law in the USA where a motor vehicle is supposed to turn right across the lane where another motor vehicle is entering it. Bike lanes are sometimes brought up to intersections, though the laws of every state except Oregon require motorists to merge into the bike lane before turning. The illustration below, from Dan Gutierrez, depicts the problem.

Right hook conflicts, from Dan Gutierrez's Understanding Bicycle Transportation

Right hook conflicts, from Dan Gutierrez’s Understanding Bicycle Transportation video and course.

Applicable sections or the Uniform Vehicle Code are:

  • 11:304 (b) — passing on the right is permitted only when the movement can be made in safety.
  • 11:308 (c) — a vehicle shall be driven only to the right of a rotary traffic island.
  • 11:309 (a) — no changing lanes unless it can be done in safety
  • 11:309 (d) — official traffic control devices may prohibit lane changes
  • 11:601 (a) Right turns – Both the approach for a right turn and a right turn shall be made as close as practicable to the right-hand curb or edge of the roadway.


Translation of complete paper on German bikeways 1897-1940

I’ve prepared a full translation of the important paper by Dr. Volker Briese of the University of Paderborn in Germany about the history of German bikeways from 1897 through the start of World War II. This has previously been available only in German, or in a highly condensed version in English in the narrowly distributed Proceedings of the 1993 International Cycle History Conference. You may read the English translation here, and also find your way to the other versions as well if they are what you would prefer.

When slow is too fast

The basic speed limit, not to go too fast under the existing conditions, is often lower than the posted speed limit.

When facilities like the bike lane in the video are built in which 10 mph, or even 5 mph, is excessive speed, and, worse, when we are required by law to use them, then we get clobbered three ways. If we ride at safe speeds, the utility of bicycling for transportation and exercise is greatly reduced. If we ride faster than is safe, then we may crash, and be held at fault. If we avoid the facilities, we may be cited for not staying in our place, and harassed. And this, when bicyclists rarely can ride at the posted speed limit.

I’ll also quote my friend Mighk Wilson’s comments about the video:

It’s important to differentiate between “fault,” which is a legal matter for our purposes here, and “contributing causes.” If we only address fault we will usually fail to prevent crashes…

So who contributed to your crash? Obviously the motorist…he’s 100% legally at fault. But the designer of the bike lane also contributed, by leading you into blind spots where you’d be in conflict with turning vehicles. You yourself contributed by traveling at a speed at which you were unable to see, react and brake for the turning vehicle. Our bicycle advocacy groups contributed by insisting that bicyclists should always get to pass stopped motor traffic even when it’s risky to do so. Our land use planners contributed by allowing commercial driveways so close to major intersections. I could go on…

Part of the problem here is not only that the bike lane leads to blind conflicts, as Mighk points out, but also that it leads to false expectations of what is safe. I’d also add that planners, and lots of other people, contributed to causation of the crash by generating patterns of land use and mode choice which lead to traffic congestion. It is ironic that while it was only safe to travel at low speed in the bike lane, the traffic in the travel lane was stop-and-go, and had stopped completely. Whether a cyclist would have been able to travel safely at a higher average speed without a bike lane is open to question.

Truck side skirts: reliable way to prevent cyclist fatalities?

No, not reliable. And they are also supposed to confer an aerodynamic advantage. Some do, some don’t.

Some have a smooth surface which can deflect a cyclist. That is still no guarantee that the cyclist will escape serious injury or death. Other side guards are only open frameworks which can catch and drag a bicycle. A lot of what I have seen is little more than window dressing.

The side guard in the image below from a post on the Treehugger blog has no aerodynamic advantage and could easily guide a cyclist into the rear wheel of the truck.

Photo of truck side with guard from Treehugger blog.

Photo of truck side with guard from Treehugger blog.

A cyclist can easily go under the side guard shown in the image below, from a Portland, Oregon blog post. A cyclist who is leaning against the side guard is guided into the sharp edge of the fender bracket and fender, and the front of the turning wheel, which can pull the cyclist down. There is another wheel behind the one in the photo.

Side guard on City of Portland, Oregon water transport truck

Side guard on City of Portland, Oregon water transport truck

The side guard on a Boston garbage truck in the photo below — my own screen shot from the 2013 Boston Bikes annual update presentation — is only an open framework which could easily catch and drag a bicycle.

Side skirt on City of Boston garbage truck

Side skirt on City of Boston garbage truck

A truck which is turning right off-tracks to the right. A cyclist can be pushed onto his/her right side, and goes under, feet to the left, head to the right. On the other hand, if an overtaking truck contacts the left handlebar end, or if the right handlebar end contacts a slower or stopped vehicle or other obstruction, the handlebar turns to the right and the cyclist slumps to the left, headfirst.

To be as effective as possible for either aerodynamics or injury prevention, side guards must cover the wheels. Though that is practical, none of the ones shown do.

But no practical side guard can go low enough to prevent a cyclist from going underneath. The side guard would drag  at raised railroad crossings, driveway aprons, speed tables etc. Even if the side guard did go low enough, it would sweep the fallen cyclist across the road surface, possibly to be crushed against a parked car or a curb.

Fatalities have occurred when cyclists went under buses, which have low side panels — but the wheels are uncovered. The Dana Laird fatality in Cambridge, Massachusetts is one example. Ms. Laird’s right handlebar end is reported to have struck the opening door of a parked vehicle, steering her front wheel to the right and toppling her to the left.

Dana Laird fatality, Cambridge, Massacchusetts, 2002

Dana Laird fatality, Cambridge, Massachusetts, 2002

The bicycling advocacy community, as shown in the blog posts I’ve cited, mostly offers praise and promotion of sub-optimal versions of side guards, a measure which, even if executed as well as possible, offers only a weak, last-resort solution to the problem of bus and truck underruns.

Most of the comments I see on the blogs I linked to consider it perfectly normal for motor traffic to turn right from the left side of cyclists, and to design infrastructure — bike lanes in particular — to formalize this conflict. The commenters also would like to give cyclists carte blanche to overtake close to the right side of large trucks, and place all the responsibility on truck drivers to avoid off-tracking over the cyclists.

Cyclists are vulnerable road users, but vulnerability is not the same as defenselessness. It is rarely heard from today’s crop of bicycling advocates, but a cyclist can prevent collisions with trucks and buses by not riding close to the side of them. There’s a wild contradiction in playing on the vulnerability, naiveté and defenselessness of novice cyclists to promote bicycle use with measures — particularly, bike lanes striped up to intersections — which lure cyclists into a deathtrap. Regardless of whoever may be held legally at fault in underrun collisions, cyclists have the ability to prevent them, and preventing them is the first order of business.

Want to learn how to defend yourself against going under a truck? Detailed advice on avoiding bicycle/truck conflicts may be found on the Commute Orlando Web site.

Additional comments about the political situation which promotes underrun collisions may also be found on that site.

How not to restripe

Gordon Renkes has produced a video showing conditions following restriping at Tamarack Circle in Columbus, Ohio, USA. Here’s a Google overhead view of this rather unusual circular street. Click away the caption balloon to get a better view. You may enlarge this view, or go to the full-featured Google page by clicking on “View Larger Map under the image.

View Larger Map

The teardrop pointer is at the location of the Google Street View below, of Tamarack Circle before the restriping. (I downloaded the image instead of embedding the Google image, in case Google redoes the Street View).

Google Street view of Tamarack Circle before restriping

Google Street view of Tamarack Circle before restriping

Before the restriping, with the very wide right lane, motorists probably parked most of the way to the corner, and many cyclists probably rode in the door zone.

Here’s the video showing condition following the restriping:

The design does encourage cyclists to ride outside the door zone of parked cars. But, as the video shows, the striping confuses motorists. Among other things, the striping instructs them to right-hook cyclists. In the video, one motorist even right-hooks another. Ohio law says:

“Approach for a right turn and a right turn shall be made as close as practicable to the right-hand curb or edge of the roadway.”

Striping which incites violations of the law risks liability claims.

Creating right-turn pockets to resolve the problems would require removal of a few parking spaces before each entering street.

If parking were on the left at the inside of the curve, sight lines at intersections with streets at the outside would be better (though worse at driveways at the inside, and for drivers exiting parking spaces, due to the curve). A combined bike lane/right turn lane (still “experimental”) would be needed due to width limitations.