Monday, September 19, 2011

Beware the right hook (and left cross) at Diamond and Canyon/Central

Beware of that right turning SUV. 
Check traffic on your left as you approach
Don't let an otherwise fine bike lane system lull you to sleep in a busy, complex, and not always optimal Phase IV.

"...In response to right-hook crashes, cities are trying to move bicyclists away from the curb at busy crossings...." --Seattle Times

Cyclists travelling northbound on Diamond Drive may now have to deal with a "right hook" hazard at Diamond and Canyon. The current configuration of the northbound bike lane puts it far to the right of thru traffic, separated from the thru lane by a buffer, and located in the place where the right turn bay used to be. I see this as a hazard because there are a lot of right turning motorists at this intersection and a lot of thru cyclists headed north on Diamond Drive. In this configuration, thru cyclists in the bike lane, who may be moving quite briskly due to the downhill slope, will be overtaken by motorists turning right from the cyclist's left. Alternatively, bicyclists will be overtaking motorists, who are slowing to turn right, in the motorist's "blind spot". In addition, cyclists riding that far right will be less visible to southbound Diamond traffic turning left onto Canyon/Central. To see examples of potential turning and crossing conflicts, go to the Mass Bike Law Officer Training page and watch the videos under "Motorist Errors..."

Here are the most relevant Mass Bike videos for the right hook and left cross. Both of these are more likely the more 'invisible" the bicyclist is to motorists. Check out the Mass Bike page for others. Most are posted on Youtube.

In addition to the crash scenerios mentioned in these videos there is a third type--a car-car collision, i.e., a motorist suddenly stopping short after seeing a cyclist riding on the right (15 seconds into the first video) could be hit from behind by an inattentive or tailgating motorist, or, a motorist stopping short while making a left turn (south on Diamond to East on Canyon) and realizing he is going to hit an oncoming cyclist could be t-boned by an oncoming motorist going too fast.

So be aware of these hazards and watch for overtaking cars that could turn in front of you. Alternatively, since this is a downhill section, and if you are travelling at the speed of traffic, you may want to take the (travel) lane and forswear that section of bike lane until you are past Central. There is no law against it, i.e., a mandatory bike lane use law. "As far right as is practicable" generally applies if you are going slower than other traffic. In this section, I'm usually humming right along and it is not considered prudent or practicable to be T-boning right turning cars with a 'cross bike.

Neale Pickett and I have both commented to the County DPW on the pitfalls of this design in this particular location and requested it be changed.  Neale has suggested, at minimum, to move the bike lane to the left of what used to be the right turn bay, suggesting the present design is awfully close to that of a sidepath. Some relevant AASHTO verbage follows on sidepaths: "...The most common crash type in this category involves the failure of a left‐turning motorist to yield to an oncoming bicyclist; the second most common involves a right‐turning motorist who strikes a through bicyclist (often referred to as a “right‐hook” crash). (5) Measures that encourage bicyclist conspicuity can be helpful, as can geometric modifications that limit vehicle turning speeds (e.g., reduced curb radii). A bike lane provided along the left side of a dedicated right‐turn lane can also help reduce the incidence of such crashes..."

Compare to this description of a "dangerous" bike lane in Portland, OR, which was changed to avoid the right hook.

Stay Tuned, and please be careful out there. Slow down and be vigilant in this section of bike lane. My preference is to reinstate the right turn bay and put sharrows in the thru lane or share the right turn bay with a bike lane dashed on its left side.  But the paint, as I was told today, is now dry.

To cyclists who want bike lanes, please remember that they are not always the right treatment. There are no good one size fits all solutions. Interestingly, County Staff reminded me that it was some cyclists who insisted on continuous bike lanes in this area. Combining that with Council's directives to staff (below) put the design in a very awkward box. Putting bike lanes in the right turn bays sacrifices the right turn bays and forces motorists to pass a cyclist on the left while they turn right. That is not optimal. Optimal is having bike lanes between the thru and right turn lane, or as a dashed part of the turn bay on the inside of the turn lane. Or, simply taking the rightmost thru lane in the direction you are going and not worrying about bike lanes.

This is what Council, in 2006, said to do:

Council passed the following motion on March 28, 2006:

Councilor Hall moved, seconded by Councilor Bowman, that Council direct staff to move forward with design of the Diamond and West Road, Trinity Drive, and Canyon Road intersections with traffic signals, no additional lanes to accommodate traffic queues, and bicycle lanes using the existing right turn lanes; in an effort to stay within the existing right-of-way. I (Hall) further move that streetlight design along the Diamond corridor conforms to Roadway Lighting Design Category for continuously lighted roadways (RLDC-5), using opposite lighting, as described in Ordinance 02-029. I (Hall) further move that staff evaluate the feasibility of pedestrian tunnels and overpasses to avoid potential conflicts with traffic at Trinity.

Interestingly, as I stopped to take the picture seen above, a motorist came barreling down this new bike lane, oblivious that it is no longer a right turn bay. Go figure.

Interesting discussions here:

Danger in the bike lane

(The Seattle Times)  Matt Corwin was pedaling home from work on his usual route when he approached the University Bridge. A line of cars waited at the red light...

Fatal Right Hook Hazard From Right Turning Motorists 

By Ray Thomas, Portland bike lawyer

Woman injured in right hook at NE Couch and Grand

I suggest those who are concerned about this call the County Dept. of Public Works or make a comment to the Transportation Board. Or, call Council. This was to some degree decided on 28 March, 2006. Above all, as a cyclist, be careful. Also, I suggest that the take home message is that these things can't be decided five years in advance without doing a detailed re-analysis of the final design.

countycouncil at lacnm dot us
kyle.zimmerman at lacnm dot  us
Transportation Board:  tb at lacnm dot  us


Tarik Saleh said...

No shit. I was going to ask you about that yesterday at work but you seemed hell bent on your patriotic yellow duties if you will...

I think this is one of those places where a bike lane is actually much worse than no bike lane. I think we would be safer with no bike lane from the bridge to the otherside of this intersection. Too much merging and criss crossing.

I have long since given up riding the bridge road at rush hour as the whole intestine to bridge seems designed to maximize bike-car problems, and I live in the Western Area so I would ride in the left lane over the bridge. I actually had someone cross the double yellow to pass me on the left when I was going 30mph on the bridge. I think that was the last straw for me.


Khal said...

I suggest those who are concerned about this call the County Dept. of Public Works or make a comment to the Transportation Board

DPW: 662-8101
kyle.zimmerman at
TB tb at

Mike said...

I've been expecting this blog post from you since I saw the lanes on Saturday. There is no question that the intersection should be configured differently.

Anonymous said...

I think a bike lane could work if it were in the left half of the now-split lane, and were either dashed or just vanished before the intersection.

If I recall correctly, the council mandated a bike lane through this intersection in 2006, so sharrows aren't an option. My understanding of county operations may be wrong though.

Neale said...

I think a bike lane could work if it were in the left half of the now-split lane, and were either dashed or just vanished before the intersection.

If I recall correctly, the council mandated a bike lane through this intersection in 2006, so sharrows aren't an option. My understanding of county operations may be wrong though.

Khal said...

If it were on the left, it would at least be more visible and obvious.

Neale said...

I made a comment on the motion that the "right turn bay" requirement could put bicyclists to the right of right-turning traffic. It should be in the minutes.

I think we're going to have to wait until somebody is hit, and then sort things out in court. I'm still overall pleased that the community was willing to make provisions to accommodate cyclists and we're now arguing over paint.

Khal said...

Paint I can argue about, Neale, without losing sleep. And I concur with your statement that the community has been good about this. My concern is that we are potentially going to be scraping someone off the road who gets right hooked.

To some degree, people are responsible for their own riding, but we should make the facilities as intuitive as possible. This fails the intuitive test.

We need to work on education, if not tearing up the paint and fixing the design to make it more error-proof. Hence all the hot air I put into this blog posting.

Most of the Diamond Drive bike infrastructure is great, and I am really happy with Traffic, Pavement, and Public Works for all their excellent efforts. But this particular location worries me a lot, and I think a lot of the problems are due to trying to fit the road around all the rules Council stipulated during that contentious Diamond debate in 2006.

Jerry M. said...

Seems there is danger at the Diamond Trinity intersection also. During the commute home in traffic, Many times the light is green, but the traffic is stopped with a gap at the intersection due to a backup at the Canyon intersection. The bike lane, however, is not backed up. You can cruise right past all the stopped cars and through the Diamond-Trinity intersection on the green... BUT cars are turning left from Diamond onto Trinity... and they won't see you coming.

I'm also seeing cars using the bike lane as turn lanes onto Sandia and onto Canyon from Diamond. Today I saw a right turner lining up in the bike lane at the Canyon intersection next to a "legal" right turner waiting in the car lane with his turn signal on.

Thursday on the way home I rode through the Diamond-Canyon intersection in the bike lane using an LA Bus as a shield from left turners coming from Diamond. Worked really well until the bus started pulling over to stop at the bus stop by the school. I slowed down to let him in. When he stopped he completely blocked the bike lane. There was no passing due to heavy traffic. They didn't make a bus pullout at this stop. Wonder why not?


Lisa said...

I noticed this striping on a ride home but ignored it and rode through the intersection in the through traffic lane. The problem with that is that some drivers think that, if a bike lane exists, bicyclists should be in it, and they can get pretty aggressive about making their opinions known to the cyclist.

Personally, I think it is safest to have the bicycle lane go away 25 to 50 feet from the intersection and then restart on the other side, the implication being that cyclists merge into the traffic lanes through the intersection. Traffic seems to accommodate this configuration fairly well when I've encountered it.

Anonymous said...

Seeing the end results of the work on Diamond Drive, I see the potential for bad bicycle/motor vehicle interactions with the new bike lanes. This has to do with the removal of the right turn lanes and making them into bike lanes, thus forcing vehicles making right turns to cross the bike lane. A prime example of this is north bound Diamond Drive at Canyon Road.

Since this is a downhill grade, bikes can easily pick up speed approaching Canyon. Drivers are generally not looking for things approaching on their right when making turns and they could easily make a turn in front of an approaching cyclist. This almost happened to me on Saturday however, the driver in front of me did signal his intent to turn and I was able to notice his signal and slowed accordingly.

I ask that cyclists be alert to the possibility for vehicles to be turning across the bike lanes and adjust your riding accordingly. And drivers, please use your turn signals and be alert to the possibility of bikes approaching on your right.

Milan Gadd

Jerry M. said...

Commuting to/from work (LANL), I have cruised through the Diamond-Trinity and the Diamond-Canyon intersections in the designated bike lane and (so far) have not encountered a problem.

I watch for right hooks using my mirror and I time my entrance into the intersections with the flow of traffic.

This stretch of road and bike lane is hazardous without a doubt. So far I consider it manageable for experienced cyclists.


Anonymous said...

I just had exactly the same experience at Diamond Drive and Canyon Road as Milan Gadd describes in his letter. I was riding in the newly labeled bike lane northbound on Diamond intending to proceed straight through the intersection. As I approached the light, two cars turned right onto Canyon from the traffic lane on my right, crossing my path. In retrospect, they were probably correctly obeying the road markings. Luckily for me one of the two signaled his turn, because I was not anticipating they would turn from there.

This signage really needs to be fixed quickly, as it invites problems. The old lane markings were better, as they directed cars all the way to the right curb lane when approaching intending to turn right. Unless and until this is fixed, I would recommend riding in the right-hand traffic lane rather than the bike lane at this intersection.

John Berg