Cambridge Civic Journal Forum

December 3, 2012

Enjoying? the Concord Avenue “raised bike lanes”

The Cambridge City Council meeting on December 3, 2012 is to address issues of debris on the Concord Avenue “raised bike lanes”. These replaced conventional bike lanes at street level. I put the term “raised bike lanes” in quotes because a bikeway behind a curb is not a bike lane. By definition, a lane is at street level, so it is possible to merge to and from other lanes. Rather, this is a nonstandard bicycle path.

This post supplements comments which I posted on my own blog before Concord Avenue was reconstructed. The photos here are stills from video shot during a ride westbound at mid-day on November 20, 2012, with moderate motor traffic and very light bicycle traffic.

First photo: Crosswalk just west of the Alewife Brook Parkway rotary is backing up motor traffic. This already generates traffic jams with light bicycle traffic. The City expects the bikeways to attract more cyclists and to lead to a major increase in bicycle traffic.

Crosswalk backs up traffic on Concord Avenue

Crosswalk backs up traffic on Concord Avenue

Next photo: The westbound bikeway crosses 8 streets and 24 driveways in 3000 feet. The most persistent hazard on the westbound bikeway is of “right hook” and “left cross” collisions. The van in the photo not only is turning across the bikeway; it also might be hiding another vehicle preparing a left turn from ahead. The bikeway places bicyclists where they are defenseless against these threats. I say more about them, and how to avoid them, in my earlier blog post.

Right hook and left cross threat on Concord Avenue bikeway

Right hook and left cross threat on Concord Avenue bikeway

Next — bus stop. When the bike lanes were at street level, bicyclists could pass a stopped bus on the left, or wait behind it. Motorists also usually could pass a stopped bus. Passing would have been even easier with bus turnouts on the westbound side, where there is only one travel lane. Now that the roadway has instead been narrowed, converting the conventional bike lanes into “raised bike lanes”, buses must completely block the travel lane, and passengers getting off a bus step down directly into the path of bicyclists. A 2007 research study in Copenhagen showed an increase in bicyclist-pedestrian collisions of 17 times, and of injuries of 19 times, when bus stops were placed outside bikeways like this. More about that study.

Bus stop on Concord Avenue, with green paint

Bus stop on Concord Avenue, with green paint

That study was published well before construction on the Concord Avenue bikeway began. Not only that, the City’s bicycle coordinator repeatedly points to Copenhagen as a model of what Cambridge should do.

To resolve conflicts between bicyclists and passengers descending from buses, the City first painted bicycle markings. Those markings, however, suggest that bicyclists have priority, and these markings also may not be directly in front of a bus’s door when it opens, to warn the passengers. At some later time, green carpet painting was added. This is normally used to indicate where motorists yield to bicyclists (see Federal Highway Administration interim approval), but here it is intended to indicate where bicyclists must yield to pedestrians, a confused and contradictory message. This bus stop is at a driveway. Traffic has worn away some of the green paint and you can see the bicycle marking which was painted over.

Bicycle marking under green paint at bus stop on Concord Avenue

Bicycle marking under green paint at bus stop on Concord Avenue

One problem to be discussed at the City Council meeting is that snow clearance is not practical on the westbound bikeway, because of its repeated ups and downs. Ice also puddles there. Here’s a photo from another blogger, dr2chase, showing winter conditions on the westbound bikeway. dr2chase’s blog has many more photos.

dr2chase's photo of winter conditions on the Concord Avenue bikeway westbound

dr2chase’s photo of winter conditions on the Concord Avenue bikeway westbound

dr2chase also has made the point that snow clearance is much more practical on the eastbound bikeway, which has only one driveway entrance in its entire length. Here is his photo illustrating that:

drchase's photo of the eastbound bikeway in winter

drchase’s photo of the eastbound bikeway in winter

The bikeway on each side is designated as one-way. People are likely to use both of them for two-way travel, and not only in snow season, because a cyclist must stand in the street to lift the bicycle over the curb of the eastbound bikeway at most locations. Also note the seam between asphalt and concrete running down the middle of the photo above. It is intended to separate bicyclists from pedestrians. It won’t, especially with two-way bicycling, and over the years, it will deteriorate so it traps bicycle wheels. dr2chase and I have both made the point that a properly-designed, designated two-way bikeway on the south side of Concord Avenue, adjacent to Fresh Pond Park, would have made good sense, connecting with the existing bikeways in the park and crossing only one driveway in its entire length — at a signalized intersection. I also would have liked to keep the street at its previous width, with street-level bike lanes, to allow efficient through travel and make it possible to reach the eastbound bikeway without lifting a bicycle over a curb.

The next photo illustrates the crossing-the-street issue. Note the driveway at the right rear, and that there is no break in the curb on the far side of Concord Avenue. To cross without stopping in the street, and to avoid having to double back, cyclists will most likely ride eastbound in the westbound bikeway. That is illegal and hazardous: motorists pulling out of side streets and driveways look in the opposite direction for traffic.

The mailbox adjacent to the 5-foot-wide bikeway adds a nice touch as well. Nick it with your handlebar, and you go down hard. Even without such obstructions, 5 feet is minimal for one-way travel. This mailbox is one of a large number of fixed-object hazards adjacent to the bikeway.

Mailbox, and curb on far side of Concord Avenue

Mailbox, and curb on far side of Concord Avenue

Not all hazards are fixed-object hazards. There are these trash barrels.

Trash barrels on westbound bikeway on Concord Avenue

Trash barrels on westbound bikeway on Concord Avenue

Behind the trash barrels, you may have noticed a car discharging passengers. A cyclist who regularly rides Concord Avenue reports that delivery vehicles also now stop in the bikeway.

Car stops in bikeway to discharge passengers, on Concord Avenue

Car stops in bikeway to discharge passengers, on Concord Avenue

My next photos show what I call the X-merge, or double-cross merge.

Normal traffic law requires a driver to maintain a constant lane position when another driver is overtaking. Here’s an excerpt from the Massachusetts law:

Except as herein otherwise provided, the driver of a vehicle passing another vehicle traveling in the same direction shall drive a safe distance to the left of such other vehicle and shall not return to the right until safely clear of the overtaken vehicle; and, if the way is of sufficient width for the two vehicles to pass, the driver of the leading one shall not unnecessarily obstruct the other.

Bicyclists may overtake on the right, according to another section of the law:

…the bicycle operator may keep to the right when passing a motor vehicle which is moving in the travel lane of the way…

When a bicyclist is directed to merge from right to left at an arbitrary location, and a motorist to merge from left to right at the same location, they are both violating the law. Green paint here is used to direct cyclists and motorists to operate illegally.

X-merge on Concord Avenue

X-merge on Concord Avenue

I avoided right-hook threats by merging in behind the stopped car so the next vehicle turning right could safely pass me on the right.

Avoiding the X-merge on Concord Avenue

Avoiding the X-merge on Concord Avenue

Before Blanchard Road, a traffic island narrows the roadway. The bike lane, between the through travel lane and right turn lane, is too narrow to allow safe clearance on both sides. Note in the photo below that the narrow median on the far side of Blanchard Road allows much more room to the left of the bike lane. The traffic island predates the reconstruction: the bike lane has been shoehorned in by narrowing the other lanes. Concord Avenue is wide enough to accommodate turning traffic without the island’s being so wide.

Wide traffic island at Blanchard Road narrows bike lane on Concord Avenue

Wide traffic island at Blanchard Road narrows bike lane on Concord Avenue

Well, enough. You get the idea. I’ll finish with a couple of quotes. Here’s one from MarkS, commenting on dr2chase’s blog post:

I don’t know why they wasted the time and money to put these tracks in in the first place. I find a bike lane much more convenient, and in some ways safer — clearly safer than that abomination on the north side of Concord Ave — the “outgoing” side. And, if ever we decide to re-design the situation, the expense of doing so will be significantly — and that’s an understatement — more than it would be to just re-paint the lines where the bike lane would have been.

Here’s another quote, from dr2chase:

…the west-bound side is about the most ineffective botch I have ever seen. But the eastbound side is quite nice (with the exception of the scary-high curbs). One extremely-low-traffic intersection, no driveways, hence none of those risks, and so wide that (with current bike/ped traffic levels) there is little harm in riding the wrong way on the good side. Technically illegal, but vastly safer, and I cannot fault someone for making the safer choice.

I agree! And have a look at the video online!





  1. […] more here: Enjoying? the Concord Avenue “raised bike lanes” « Cambridge … This entry was posted in Blog Search and tagged attract, bicycle, bike, bikeways, bus, crosswalk, […]

    Pingback by Enjoying? the Concord Avenue “raised bike lanes” « Cambridge … | Bicycle News Gator — December 3, 2012 @ 3:18 pm

  2. I think you overestimate the speed of seam wear on the eastbound side. No cars means vastly reduced wear-and-tear on the sidewalk/cycletrack surface. Also, as a general rule I use and recommend the fattest possible tires, because all the roads I ride on are filled with potholes and seams, and that reduces those hazards.

    The green bus-stop pads are very new, probably within the last month. It is not exactly clear what they are intended to mean. I think there is some other indication that cyclists are supposed to give way to passengers entering or exiting the bus, so my guess was that the green pads were intended to make waiting passengers (no bus stopped) aware that bikes might be passing while they wait (that is, please do not stand in the bike lane if there is no bus).

    Overall I’ve had fewer conflicts than I would have predicted on either side of the road, and I’m a little surprised by this. I would have expected much worse on the west-bound side with all the (potential) auto cross-traffic.

    The X-merge is my least favorite part of the entire show because it is a relatively novel hazard. Proceeding through the intersection is also not fun, because the right-turning traffic (on your right) sometimes drifts left a little bit before turning, and the straight-through traffic is crowded by a signal island on their left so they tend to drift right.

    I’ve tried two variations on crossing there, not sure that I can or should recommend either one, though I have a modest preference for the second option.

    I sometimes improvise an ASL there if the light is red, creeping forward to the edge of Blanchard — but if you do that, be aware of side traffic to/from Griswold. It’s not intrinsically unsafe, since you should go forward slowly (go fast, and you’ll freak out the cross traffic, not nice), but it’s something to be aware of. That headstart gets you clear of the squeeze.

    An alternate maneuver is to ride west on the east-bound side and traverse Blanchard as a “rolling pedestrian”. The right-turn lane is usually low-traffic and easy to read. The next step relies on either getting a walk signal and then sidewalk-riding up to where the median is cut for the Temple parking lot and taking a left there, OR timing the light+traffic to insert yourself into the north-bound-turning-west traffic from Blanchard and make a left turn. The main hazard here is if you try to cross on the green and west-bound Concord traffic turns left onto Blanchard; they’re behind you and out of sight.

    Comment by dr2chase — December 3, 2012 @ 4:58 pm

  3. In reply to dr2chase: Thanks for your comments.

    Indeed, on poles before some (though not all) of the bus stops, there are little “bike yield to bus passengers” signs. I never noticed them until I reviewed my video just now. The signs were above my line of sight as I scanned for surface conditions and traffic. The inconsistent and irregular placement of these signs leads me to think that they an afterthought, like the green pads. Modus operandi: overlook a potential problem, than when it crops up, attempt to fix it in ways that are ineffective and increasingly complicated. Bus passengers will still have to step across the bikeway and also will block the sidewalk. Cyclists will have no safe option but to stop and wait. Some will be too impatient to do that.

    Yes, the bike lane after the X-merge is narrow. The traffic island just before Blanchard Road is unnecessarily wide, squeezing all the lanes to the right of it — another design gaffe which you have pointed out. I’m adding a photo and comments about it to the post. I use a rear-view mirror, so I can see whether the next vehicle behind me is in the lane to my left or my right, and choose my lane positioning to allow enough passing clearance. Lacking a mirror, or if there are vehicles in both lanes, the safest option is to merge to the left of the bike lane to forestall unsafe overtaking.

    I agree that transitioning to Blanchard Road when traveling westbound on the eastbound bikeway is an issue, and you describe several clever ways to address it. I’d hope that it would be addressed through design, for example with a left-turn waiting area and signal timing to ease the left turn from Blanchard road northbound to Concord Avenue westbound. As the bikeway on the south side of Concord Avenue is not designated for two-way travel, that probably won’t happen.

    As to the settling of the seam, time will tell. This has been a problem repeatedly on the Paul Dudley White paths along the Charles River, where part of the path’s width is on the stone retaining wall next to the river and part is asphalt-paved.

    Comment by jsallen — December 3, 2012 @ 10:36 pm

  4. I’m not sure my methods for dealing with Blanchard Road count as “clever”; I don’t feel comfortable recommending them because each has its own hazard (which can be mitigated by looking carefully). I wonder if the difficulty of plumbing any path into Belmont may have been a partial cause for the two-side cycle track.

    I reviewed the seam today, and my fat tire bias is clearly at work. With very skinny (7/8″) tires, the existing seam might be a problem in places, even without wear. However, anyone traveling to/from Belmont with such skinny tires will endure much worse as soon as they cross the town line.

    There is also a partial alternate route around Fresh Pond itself, though it seems to be an off-leash dog area.

    Comment by dr2chase — December 4, 2012 @ 8:45 pm

  5. You might be interested in the Warrington Cycle Campaign’s “cycle facility of the month”
    which is worth a google if you haven’t come across it.

    It tends to the sarcastic and mainly is UK based, although I have seen one from Amsterdam…

    Comment by Jim Parkin — April 14, 2013 @ 1:22 pm

  6. Yes, I’ve seen it. Cambridge deserves a spot on that site. The bowling-alley bus stops on Concord Avenue would be my favored entry. (Bicyclist plays bowling ball, passengers stepping of the bus get to be the bowling pins…)

    Comment by jsallen — April 14, 2013 @ 8:40 pm

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