Saturday, December 19, 2009

Dashes in Brookline

Regular readers know of my odd fixation about infrastructure. I can't help it. I just notice things about the streets, bridges, pipes and power line and wonder how and why.

Here's the latest, and I am hoping someone can explain. The Town of Brookline recently repaved Longwood Avenue. Then they painted these dashes on the road. I can't figure out what they are for. They clearly do not delimit a bike lane. Are they meant to provide a guide to drivers as to the appropriate position in this lane? If so, they don't quite work, as seen in the video. If you cannot view this embedded video here, you can use this link to YouTube.

Any theories from my readers, serious or humorous?

16 comments:

KERaven said...

Saw these myself 2 weeks ago and had absolutely no idea what they indicated.

Paul Levy said...

Transferred from Facebook:

Corey: Well dashes usually indicate you can pass cars if traffic allows it, but I don't know if that would be the case on Longwood...

Jamie: I think it lets the bikers know they can ride in the same lanes as the cars.

Shirley: I wondered about this myself. I think it would be a great lane for a bike tour.

And from Twitter:

@bobegan: A "highlight" for municipal vehicles in particular schooled buses who drop kids off in the cross walk.

@nanarcr: Very confusing to those of us who drive into medical facilities from out of town. Where IS the lane? How many lanes?

Anonymous said...

Maybe it's a new test for political correctness--to embarrass anyone whose car isn't small enough to fit inside the dashed lines? But if so, I am surprised that Cambridge didn't do it first....Could also be something to try to get the attention of drivers so that they stop cell phone calls and texting for at least a few blocks...

Paul Levy said...

More comments from Facebook:

Amy: as I was driving down the street the other day trying to figure out how my car was supposed to fit between any 2.

So weaving along I decided to center the car on the the left one, which created a really nice bike lane, to the right of the right one!

Then I wondered, what they had in mind?

Amr: It looks as if they were confused where to draw the yellow lines...
First they made a dashed line in the middle of the street, but they realized that it is a 3 lane street and they can't make it 1.5 lane in each direction.... so they decided to make one side 2 lanes and the other 1 lane as usual... but they were confused which side to be 2 so they made the dashed line on the right side then they chose the other side and they left the marking dashes....:-))

e-Patient Dave said...

Most likely something legislated into a mandate, pushed by lobbyists for the Street Paint Manufacturers' Association. :)

Or maybe the SPEU. (Street Painters' Employees Union.)

If my guess is correct, after a few accidents happen, the same govt will mandate removing the paint, using Street Paint Remover (produced by members of the same organization of course).

And anyone who opposes either move will be declared to be opposed to citizen safety, in favor of death panels, opposed to job security or economic growth, etc etc.

Just sayin.

Seriously, should ask the town what those dashes mean.

Kyle said...

I was just talking with friends about these dashes last night! I walk or bike down Longwood from Coolidge Corner to the medical area every weekday, and I do like the dashes when I'm on the bike - they are a nice guide for holding your line on the street, though I'm not sure if that's what they're for.

Laura said...

I had wondered the exact same thing. I think that, if your video is any indication, they're probably a guide to keep cars a safe distance from bikers. As you look at the dashed lines and wonder, "what the hell are these for?", you are subconsciously guided to keep your car to the left of the outermost dashed line. Hence, plenty of room for bikers to ride between moving traffic and parked cars (with all those doors just waiting to be flung open).

Mike Sandman said...

The dashed lines are for a shared bike lane. It indicates to drivers that cyclists may use the main travel lane. Shared bike lanes used when there's not enough width on the street for a full bike lane along both curbs. The shared lane keeps bikes further away from doors that could be opened into their path. Longwood carries a substantial amount of bike traffic and it's a realtively low speed street for car,s so it's a good canditate for a shared lane.

There's also a new "normal" bike lane marked on the eastbound side of the street, but there wasn't enough width to allow for bike lanes on both sides.

In some cities this type of lane is marked with a "sharrow" -- see this link for a photo:

http://bikehugger.com/2006/12/whats-a-sharrow.html

I don't know whether Brookline's DPW is planning to paint sharrows in the lane, but.. I'll find out and update this post.

Mike Sandman - Brookline Transportation Board chair

e-Patient Dave said...

Mike, great to hear from you. Thanks!

Now here's the challenge: apparently local people don't KNOW that. Can you do something about that, like put up signs?

I like the idea and your explanation but if I may be so bold, if drivers don't know that, I doubt it'll help. (I'm a bicyclist, too, and I didn't know that.)

Maybe signs at stop light intersections, where bikes and cars alike have time to read them?

Adam Gaffin said...

Sharrows! Bike advocates or somebody need to do some serious driver ed. They popped up on American Legion Highway in Roslindale and Mattapan a few months ago and I had no idea what they meant (I thought they indicated a bike lane was coming up since, in fact, that's what happens on that road).

Paul Levy said...

Story picked up here, too, by Wicked Local: http://blogs.wickedlocal.com/brookline/2009/12/21/the-story-behind-the-myseterious-dashes/

Mike Sandman said...

There's definitely a need to explain to drivers and cyclists alike what a shared lane is, and how they're marked. We'll try to get the TAB and the Globe to help us with that task. And there will be more "Share the Road" signs in Brookline and more broadly in the Boston metropolitan area. The signs have bike symbols on them so drivers understand who they're sharing the road with. ;-)

Mike Sandman

Peter Furth said...

Note from Paul: Reply from Peter Furth, at Northeastern University, to my query, "Was this your idea?"

Yes, it is my idea. The dotted lines *are* meant to indicate a bike lane. But not the usual, exclusive bike lane; rather, a "lane-within-a-lane" -- a bike lane within a general travel lane. I call it a Bicycle Priority Lane, analogous to priority seating on a bus -- if a cyclist is there, yield the space to them; if not, you can drive there. However, the construction is not complete, having been interrupted by the arrival of winter. Between each set of dotted lines there is supposed to be a bike silhouette, capped by a double chevron (arrowheads). They will be installed once spring arrives. (Likewise, bike symbols will be installed in the bike lane on the eastbound side of the street; as it is now, without the bike symbols, it looks like a shoulder, not a bike lane.)

To understand the bicycle priority lane, you first have to understand what it means to be "doored" -- to strike the suddenly opened door of a parked car. Dooring is one of the leading causes of bicyclist injury and fatality on urban streets. Even if a door catches only half an inch of the bicyclist's handlebar, that's enough to suddenly turn the bike's front wheel, violently throwing the bicyclist down and away from the parked car, right in the path of the next arriving motor vehicle. Doors usually open too suddenly for the bicyclist to react; I know, because I was doored once on Dorchester Avenue. The same kind of crash can happen when a cyclists' handlebar hits a car mirror, if the cyclist rides too close to a parked car. That may be how a cyclist recently died at 50 Longwood Ave.

The bicycle priority lane is meant to encourage safe lane-sharing where a travel lane is too narrow for a bike and car to share it side-by-side, and where instead the desired behavior is for bikes and cars to share the lane single file, one behind the other. On a street like this, bikes should be able to proceed without fear, staying just outside the door zone, while cars drive patiently behind them a bike until a break in opposing traffic makes it safe for a car to pass. In the bicycle priority lane, the outer dashed line is 10 ft from the curb, because that's the edge of the door zone (allowing 7 ft for a parked car and 3 ft for its door). The other dashed line is 15 ft from the curb, indicating a 5 ft wide "lane" where a cyclist should be expected to ride.

Absent a deliberate lane-sharing treatment like this, the desired mode of lane sharing doesn't automatically happen much of the time. Too often, bicyclists feel pressured to not "block the lane," and move so far to the right that they put themselves at risk of being doored or squeezed against a parked car. In a similar way, motorists often feel that something's wrong if they are forced to slow down to the speed of a bicycle; somehow, in our thinking, a bike should never block a car. When a bicyclist is blocking a car's lane, some motorists will honk and yell at them, and sometimes pass at high speed with only a few inches'
clearance, intentionally threatening and terrifying the cyclist.

By marking the preferred bike "path" at a safe distance from the parked cars, we emphasize in black and white that a bike "blocking the lane" isn't being inconsiderate or illegal; it's where they're supposed to ride, without fear and without pressure. It's part of a much larger plan to make Brookline a bike-friendly community, along with more bike paths and bike lanes.

You can read all about it in a paper I wrote on the topic; it includes a photo of a similar treatment in Salt Lake City and similar treatments in the Netherlands.

https://myfiles.neu.edu/xythoswfs/webui/_xy-5458369_1-t_BQRThjqj

Your movie, in which car tracks miss the dotted lines, is reassuring, because having the cars miss the lines means the lines will last longer.

massmarrier said...

Intriguing lane marking. I was initially trepid about the shared bike/bus lanes on Boston's Washington street from Melnea Cass to the Floating Hospital. Now I love them. Bus drivers don't run me down. Sure, jerks double park in that lane even when there are free spaces for them to pull into, but in the main, I feel safer. Car and bus drivers alike respect the markings and concepts. More please, including this priority variation.

Kay Stoner said...

A great idea.

Looking forward to the spring, when the pix of bicyclists are put in.

Anonymous said...

Interesting. But why not just use the usual bike lane markings, placing them in the middle of the lane? It should be pretty apparent that cars can't fit between the bike lane and the yellow line, and therefore both bikers and cars realize they have to share the road. With the dotted white lines I think most drivers will just be confused, even with some publicity... lots of people come from all over to this area.