Eyes on the Street: Mixing Zone, D.C.-Style

Reader Mike Epstein sends in this photo of a “mixing zone” on L Street in downtown Washington, D.C., that looks a lot different than the ones here in NYC. Mixing zones are the areas where bike traffic merges with turning car traffic at the approach to intersections along protected bike lanes. New York’s mixing zones don’t have flexible posts, and the markings are supposed to emphasize that drivers should yield to passing cyclists, instead of directing cyclists to merge to the right of turning cars, as seems to be the intent in D.C.

Here’s a look at a couple of NYC mixing zones for comparison. This one, courtesy of John del Signore at Gothamist, is on Second Avenue:

And here’s a look at a mixing zone on Grand Street:

Personally, I like the D.C.-style markings, which describe the movement I tend to make at NYC intersections to avoid getting hooked by turning drivers. The posts would be nice to have, but I expect they would get flattened by New York’s careless motorists. Some sturdy steel bollards would do the trick though.

In the absence of hard numbers about the safety records for each type, which one looks better to you?

  • In SF, we have mixing zones more like the DC one… no posts, but “dashed green” in the mixing zone, and the cycle lane repositioned to the right of turning cars. The “dashed green” does alert drivers to the fact that “here be bicycles,” which is good… It’s by no means perfect though, there’s always a bit of jostling between cyclists and cars at the right turn at Grove and Polk in the Civic Center, for instance. But then there’s always going to be an issue when there’s a right turn across a bike lane, and it’s a reasonable way to try to address the problem.

  • krstrois

    Seems like the bollardy things in DC lane would slow down traffic and prevent cars in center lanes from turning left into cyclists, which is my one anxiety when riding in the protected lanes on Manhattans’ avenues. 

    I’m not sure what is more effective from a safety engineering standpoint, but I am always happy when I see a physical barrier of any kind. 

  • Anonymous

    The DC idea is good, but I worry that it will be confusing to motorists who’ve never seen it before, and that you’ll see clueless motorists turning left from the second lane after they miss their chance to switch to the turning lane.

  • M to the I

    The DC mixing zones look great and I like that there is a sign telling drivers to yield to bikes.

    The mixing zones here in NYC are pretty terrible. Drivers rarely yield to cyclists and probably don’t understand that they are supposed to yield. Many speed up when they see a cyclist, drive in the white buffer zone, and cut off cyclists to make their turn. The mixing zone allows drivers to make a wider turn so they can do it at higher speeds, and they do!
    Lots of truck drivers and car drivers don’t use the mixing zone and turn from a thru traffic lane which is really scary for a cyclist not expecting it. I think a lot of drivers have no idea what the mixing zone is. It would be nice to have some turn arrows in there so that drivers get it. Also, lots of trucks illegally load and unload in the mixing zone, leaving space between the truck and curb for bikes but creating a dangerous situation at the intersection with drivers making a blind turn through the bike lane.

    The bicycle markings are placed incorrectly. The DOT says that bicyclist should merge behind vehicles and not stay along the curb to avoid being cut off. Well, then the bicycle markings and sharrows should be in the middle of the mixing zone and not along the curb.

    Pedestrians walk out into the street and queue in the mixing zone. As bicycles and cars move through, they end up standing on the narrow painted buffer. I could go on and on.

  • Belleoflonglake

    I rode L using Capitol Bike Share when I was in DC last week and I really preferred it. It makes it clear that the car is entering bike space and, since the merge happens mid-block, when you get to the intersection you can ride through without worrying about getting hooked.

  • Guest

    I’ve ridden both and prefer DC’s.  DC’s version provides one precise entry point for drivers, making the prediction game far easier when I’m on my bike.  In NYC, drivers have a very long stretch where they can merge with the bike lane, and it’s hard to know exactly when they might cut you off completely.

    The plastic delineators certainly aren’t going to stop a careless driver, but they do deter more casual instances of motorists parking and forcing cyclists into an even bigger shared space with faster traffic.  I know there are issues with street cleaning and snow removal in some locations, but these should be installed where possible in mixing zones and on any bike lane that runs along a curb, such as the east side of Chrystie Street going uptown from the Manhattan Bridge. I’d even love a single post in the middle of the jughandle at the intersection of Bowery and Prince to deter motorists from stopping there.

    By the way, the Grand Street picture is probably an imperfect comparison to the DC image since there’s a parking lot at the corner of Wooster street that would make any form of separation there fairly impossible.

  • Seth R

    We could definitely use some of this in NY.  The problem is that the more courteous drivers stay to the right, out of the way of bicycles, which leaves me with no room to pass them on the right without zooming into traffic.  It would be very helpful  if DOT could come up with a way to leave some space while merging across the lane of turning cars.

  • jrab

    The DC picture looks more similar to NYC’s alternative to the mixing zone, the dedicated left turn lane with special left-turn signal.
    I have found in my own cycling experience that motorists making left turns from mixing zones on First Avenue will not move all the way to the left, but instead will hedge their bets by leaving room on the left for bikes (so that cyclists can get left-hooked? great!).
    I think the wiser course would be what Joe R. has promoted on Streetsblog pages, to prohibit left turns entirely for several blocks in a row, then at the 23rd-Street type streets, have the dedicated left turn lanes.

  •  I think L St. has worked better than most of us thought it might though there are still some issues.
    To @qrt145:disqus ‘s point, some drivers do indeed miss the mixing zone and try to turn from the 2nd lane from the left.  I’ve noticed less and less doing this however, and when it does happen many give up the turn and continue straight to the next block.  You do have to be alert to this though.  I’ve had to yell at a number of drivers attempting this maneuver
    I still feel it would be helpful to paint a “yield to cyclist” sign in the general travel lane prior to the mixing point to eliminate any confusion regarding who has priority.
    The plastic bollards have taken a beating.  There are several missing, often at the entry points to the mixing zones.  I still see drivers go between bollards when traffic is backed up in order to get to the left turn lane or enter a garage..they are spaced too far apart.  There is a rumor that the bollards may be replaced by a curb or something more permanent in the future.  Additionally, bollards were removed at the beginning of each block to prevent motor vehicles from entering at that point.  We were told they were removed to prepare for clearing snow which hasn’t come this winter.  They were supposed to be returned by 2 weeks ago, and have not been.  Motorists entering at the beginning of the block is not as much of a problem as it was immediately after installation. 
    Probably the biggest problem I notice is drivers not pulling far enough to the left at intersections leaving a very small gap between them and moving traffic from the right.  It often forces us into the general traffic lane for a moment.
    The other major problem we’ve encountered is delivery vehicles parking in the spaces.  DDOT had dedicated space on the opposite side of the street for deliveries and delivery vehicles are supposed to use those or alleys, but it still happens regularly, though generally during non-peak periods.  http://whosblockinglsttoday.tumblr.com/

  • I used to truly despise the mixing zones on 1st and 2nd Avneues, and after using them for years, now I just casually loathe them.  There’s just waaaay to much empty space near the intersection and cars really don’t seem to navigate the zone with any consistency or care.  I see way to many cyclists trying to get in front of turning vehicles rather than taking the outside part of the zone closest to traffic.  The lane markings for cyclists should indicate that they should pass cars on the right rather than try to continue straight ahead.  

    My biggest gripe however is that drivers follow so closely that they never leave gaps when more than one vehicle is waiting for a crosswalk to clear.  What you get is a slowly moving wall of cars inching towards the crosswalk and completely blocking the entire zone.  It’s really easy to wind up coralled by the cars and stuck waiting for traffic to clear.   

    Just FYI, there are in fact signs instructing drivers to yield to bikes at every single intersection on first and second avenue.  Not that anyone has seen them or cares, but they are there.  

  • Clarence Eckerson

    Experience the mixing zone with POV video!

  • When I first saw the DC pic I thought maybe I liked it better than NYC.  But now that I think again I realize that the flexards could keep the cyclist in almost as much as the keep the motorists out.  So if I see a motorist about to enter the mixing zone in the DC setup, I have to navigate the flexards to get to the right and pass that vehicle on the right, or just come to a stop and ride behind that vehicle single file until it completes it turn.  the vehicles in the MV traffic lanes that I’m merging with and across may not expect to see me popping out from the flexard barrier, making it perhaps more dicey still.

    I think I’ll stick with the NYC setup, but I’ll make sure to try DC’s next time I’m down there.

  • Joe R.

    Mixing zones are a bad idea, period. You replace one point of potential conflict (the intersection) with two (the intersection and the mixing zone). Easier way to do it is to put a turning lane next to the bike lane. The left turn lane replaces the parking which is normally present next to the protected lane. To avoid conflicts, you have a turn signal for cars in the turning lane. This signal only goes green if the bike detector in the bike lane doesn’t detect any bikes within, say, 100 feet of the intersection. Besides avoiding another potential point of conflict, the bike lane can never be blocked by turning cars merging into it. Also, bikes always get the right-of-way over turning vehicles as they should.

  • @2555783a6f62598b6aadd2d882a4830f:disqus Your idea sounds reasonable, but NYC does not have any kind of detection equipment in the pavement and as such left/right turn bays decrease the time that the light is green for cyclists(see 23rd Street/14th Street etc..).  Given the number of signaled intersections in Manhattan, I want more time with a green rather better protection from turning cars.  
    The big problem with mixing zones is that pedestrians traveling in the same direction as traffic also have the right of way.   At peak times cars cannot complete their turns and if more than one vehicle is queued up for a turn the mixing zone becomes full and difficult for cyclists to navigate.

  • Joe R.

    @twitter-1528021:disqus It’s trivial to install such detection equipment at the same time you install the turn signals so you’re not stealing any green time from the cycists. All it consists of is wires embedded in the pavement. And maybe you can even have pedestrian detectors in the crosswalk which the turning cars would cross so as to keep cars from turning unless both the crosswalk and bike lanes were empty. This way cars won’t start turning until they have a clear path to finish their turns, avoiding the problem you mentioned. While we’re at it, since the bike detectors are already there, on bike lanes with light bicycle traffic you can use them to give bikes priority over motor traffic at intersections. This would only steal a small percentage of green time from the cross streets, but will let bicycles travel at much higher average speeds.

    I would really like to see a lot more use of detectors in general in NYC. One of my pet peeves is when lights go red with nothing crossing. Whether you’re a cyclist or a driver, when this happens, the state is stealing time from you for no valid reason. We easily have the technology to keep lights from ever going red unless something is crossing. We should require the state to use it, or to remove the traffic light if they won’t.

  • Clarence,

    Thanks for posting that video.  When I originally saw the plans for this on “d.”‘s (District DOT)  website, I REALLY liked it.  I even had a discussion with the designer.  It provides protection for cyclists between intersections but encourages cyclists to reposition themselves to prevent a left hook.  I like it because it does conform to the principles of vehicular cycling.

    However, now seeing these photos and Clarence’s video, I’m concerned that the left turn lane is very narrow and that drivers might think they can slip passed cyclists on their right or will try to force their way around.  I’m not so sure the shared bike / left turn lane really works or conveys the idea of how to properly using this facility.  I’m not 100% sure from seeing it now!

    I think the facility would work better if it just plopped straight traveling cyclists in the middle of the left turn lane or it made the left turn lane an exclusive left turn lane and provided a proper (not shared) bike lane to the right of left turning motor traffic.  Space was likely a limiting factor here. 

    Either way, I like the DC solution much better than the NYC as the NYC solution breaks VC rules and strongly encourages bicyclists to stay to the left (left side bike lanes) and cars to stay to the right as cars make their left turns.  Even I as an LCI find the NYC facility very difficult to use in a VC fashion. 

    Still, I believe the DC solution could only have come about after seeing NYCDoT experiment, observing and working off the shortcomings of the NYC innovative but honestly experimental design. 

    Only through practice can one become perfect!

  • AlexB

    If I remember correctly, at most of these types of intersections in New York, there are separate light cycles for left hand turns and bikes, which means there is no reason for the bikes and cars to cross before the intersection.  In DC, it may just be one general green light for cars, pedestrians, and bicyclists, in which case their arrangement makes more sense.

  • Noah Berland

    There is one Mixing zone kind of like this in NYC that I know of. Allen/1st ave south of Houston heading north. We don’t get all of the fancy colors and flexible posts, but it does have a shift over of the bike lane to accomodate a turning lane queue.

  • @twitter-22824076:disqus the cycle track is the width of a full traffic lane before the mixing zones and after the intersections.  It does occasionally happen that a car gets stuck in the mixing zone and you have to maneuver around it, but the car is blocking other cars from using that lane anyway so it’s not generally an issue.  As I mentioned in my previous comment, drivers seem to be adjusting quite well and allowing cyclist their right of way through the zone first, even when the cars are in front of them and about to enter.
    @2995d81157fecd50fe4b728419a38787:disqus The biggest problem I encounter is drivers not positioning themselves far enough to the left, ie. They straddle the green paint and the left turn lane.  That forces cyclists out into the intersection a bit and into traffic continuing straight ahead.  If a cyclist wants to turn left, we simply take the left turn lane and do not go into the green painted portion at all.  Obviously we’re not supposed to undertake on the left of left turning vehicles, but I do see some cyclists do that.  I did it myself early on, but stay in a primary position now and wait for my turn.  If the light turns red, we can filter to the front where there are bike boxes across all of the lanes.
    The BEST part about the L Street cycletrack is that it has really tamed traffic speeds and mitigated lane changes by drivers.  It was a free-for-all prior to installation and speeding was rampant.  Lanes were simply a suggestion and the paint was very faded in many places.  The four blocks I am on L Street was easily the scariest/most dangerous part of my 7 mile commute before, and you really had to be confident and take the lane.  I didn’t see a lot of casual users on L before, most would go onto the sidewalk, which in the Central Business District, is illegal in DC.

  • Ryan,

    That the left side of the bike lane is only dashed indicates to me the drivers are supposed to straddle into the bike lane and if a car is there, you on your bike are to wait behind them before heading straight.  I haven’t ridden it but I am sure the cycletrack is MUCH better than the free-for-all prior to its installation which is why as an LCI I support the construction of amenities that make people safe so long as they don’t violate long accepted rules of the road.

    I think d. has something great here.  But that there is uncertainty on how the facility is to be used is a sign to me that it needs a bit more refinement.  Still, hats off to d. for introducing this design!

  • Anonymous

    Rode L Street last week at the Bike Summit.  Found the cycle track a bit narrow at the left turns. Only one big SUV raced past on the left too close and too fast.  Straight through cars to the right of the cycle track are still traveling pretty fast – too fast to stop if a cyclist were to fall over.  But, as others have said, L Street was much worse before the cycle tracks went in – then it was all lanes that cars went to fast.  Unfortunately there is no more space between curb faces to widen the cycle track at turns unless right side parking was eliminated, or sidewalks narrowed.  Neither outcome is likely.

  • That’s an interesting setup. The problem with the bollards like that is it can trap you in when you need to move over. But it probably works better than in NYC because cars are forced to slow down and yield to bikes.

    The original cycle tracks on 8 and 9 Av have separate signals to hold turning traffic until pedestrians clear; in other places you have a line of cars waiting to turn and blocking the intersection, which is a big problem. An unsignalized “mixing zone” only works if turning traffic is very light.

  • Hilda

    I prefer the NY version for NY. I think we could all agree that NYC drivers would miss the opening, and turn anyway after passing the flexible posts. I usually head out to the regular traffic lane, not just the mixing lane, as the next corner is typically full of people standing in the street, especially on 2nd Ave.

    I don’t see why the green isn’t just continued without the white stripes. The white stripes are what (are supposed) to indicate to drivers not to cross, not the green. The green just helps to indicate that cyclists are there.

  • The L Street mixing zone seemed a little overly fussy to me, but after a few blocks the movement starts to seem pretty natural. Maybe I haven’t ridden it at peak times, but I’ve only once been in a situation where the weaving could have created a conflict, and that was a clear instance where the driver was not watching for cyclists before merging left.

    As for separate signals, legislation is pending that would formally allow bikes to cross with peds; since there are LPIs in downtown DC, that gives bikes a slight head start on cars.

  • Nick

    The positioning behavior you complain about is precisely the behavior that is expected and desired. The mixing zone is *not* wide enough for bicyclists and motorists to share the lane side-by-side, and the design is intended for all users to go single file. No passing should happen within the zone.

  • Guest1000

    Why are the mixing zones on 9th avenue different–better–than the others in the city? Is it because it was the first constructed?

  • Pleaseanswer

    why don’t any other protected bike paths in nyc use signal timing like on 9th avenue?


Plan for Grand Street Cycle Track Features New Design Treatment

DOT has unveiled plans for a Grand Street cycle track [PDF] that bear the fingerprints of Danish planner Jan Gehl. It would be Manhattan’s first cross-town protected bike path. Grand Street is narrower than Ninth Avenue, where the existing protected path runs. Whereas the Ninth Avenue cycle track uses signal timing to prevent conflicts between […]