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Introducing the two-stage bike box

As urban bicycling becomes more common, new types of infrastructure are being invented to help bikes safely mix with cars. The latest innovation is what's called a "two-stage bike box." Arlington is proposing one for this particularly confusing intersection:

Image by Arlington County.

This intersection, of Wilson, Washington, and Clarendon Boulevards, is often referred to as "Clarendon Circle," because it used to be one. During the 20th Century the circle was removed and the intersection widened. Now Arlington wants to make it safer for pedestrians and bicyclists.

There are a lot of interesting things going on with this plan, but the most interesting is the bike queuing zone in the lower right corner of the intersection. The idea is that cyclists hoping to cross Washington Boulevard in order to move east along Clarendon Boulevard will have a dedicated and safe place to wait, separated from both cars and pedestrians.

The two-stage bike box is similar to regular bike boxes, except that it's located in a reserved corner of the intersection rather than between the crosswalk and stopping stripe.

A normal bike box behind the crosswalk on either southbound Washington Boulevard or eastbound Wilson Boulevard would be less versatile, because it would only benefit cyclists on that one street. The two-stage box helps people moving onto Clarendon Boulevard from both Wilson and Washington, which is why it's a clever innovation at this location.

There are a few two-stage bike boxes in Portland and New York, but they use a somewhat different design. Clarendon Circle will be the first implementation of this idea in the DC area, and will also be the first-anywhere use of this particular design, which hugs the curb in an inverted nub.

Cross-posted at BeyondDC.

Dan Malouff is a transportation planner for Arlington and professor of geography at George Washington University, but blogs to express personal views. He has a degree in urban planning from the University of Colorado, and lives in NE DC. He runs BeyondDC and contributes to the Washington Post


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I would also suggest no turn on red signs from Wilson to Washington (in both directions), if those don't already exist.

by BFM on Feb 23, 2012 10:44 am • linkreport

The money shot is on page 4 of the pdf presentation. Essential in this plan is closure of Irving St. at the intersection.

I like the bicycle queue box, but how much bike traffic goes through here anyway? And wouldn't we need one on the opposite corner?

by Jack Love on Feb 23, 2012 10:59 am • linkreport

This basically takes the concept of the "box left turn" which is in use by cyclists and moped riders all over the world, and paints a green space on the ground for it.

by orulz on Feb 23, 2012 11:00 am • linkreport

That intersection also has a weird elevation that cuts down your sight line. But the fixes look good and will help calm down a pretty chaotic area where you have a lot of pedestrian activity but still an intersection built for blazing speed for cars.

Now move on down to Wilson and Glebe. Lord help anyone walking through there who is the least bit feeble. It doesn't help that the construction of one of the new buildings going up on that corner has completely denied any pedestrian access.

by Canaan on Feb 23, 2012 11:02 am • linkreport

@BFM (no turn on red) You can't go RTOR from Wilson to Washington, at least not legally, because you'd cross Irving on either side. If Irving is closed on the south side (the Silver Diner side), you'd have the opportunity, but that would carry you right through the bike queue box.

I'd even go so far as to suggest a right turn on arrow only, given the pedestrian load in this intersection.

by Jack Love on Feb 23, 2012 11:05 am • linkreport

@jack love,

My guess is that if you're west bound on glebe trying to go north onto washington then you have a myriad of opportunities to cross over to wherever you're trying to get to. Whearas thats not the case the other direction.

by Canaan on Feb 23, 2012 11:05 am • linkreport

@Canaan.... wait, what? Glebe? That's a north-south highway. And Washington is east-west.

Yeah Glebe is a mess too, especially there at Fairfax Dr. and Wilson Blvd.

by Jack Love on Feb 23, 2012 11:12 am • linkreport

Sorry, that was two separate thoughts. Coming westbound on wilson and trying to get somewhere on washington (say pershing dr.) east of there you have many more opportunities to cross over somewhere where you don't have to deal with that crazy intersection. Coming from from say the GMU lawschool to the Clarendon metro station you pretty much have to go through that intersection if you don't want to go way far out of the way. Thats why I'd guess the bike box is only reccomended for one corner.

My comment about wilson and glebe isn't related except for I think thats an even worse intersection for pedestrians.

by Canaan on Feb 23, 2012 11:16 am • linkreport

Ah yes, reviewing the street alignment in that area (which is really foggy in my minds-eye), I got to thinking that's maybe what you meant, b/c I can see the ride-thru potential.

I worked for awhile close to Glebe and Fairfax, walking up from Metro. Hated hated HATED those crossings - folks coming off of I-66 (or racing to merge on to 66) forget that they're not quite on the interstate. Red light runners were rampant - the city could get a lot of revenue by patrolling there.

by Jack Love on Feb 23, 2012 11:23 am • linkreport

Ah, I can finally see in this version that the bike lane on Wilson will be extended slightly West to at least Fairfax Drive. Though I hope they leave the entrance to Fairfax drive open to bikes at least, as it's the connection to the rest of the east/west route.

by Kolohe on Feb 23, 2012 1:20 pm • linkreport

@Jack Love - re: how much bike traffic uses this intersection, I imagine that as the Rosslyn-Ballston expansion of CaBi continues to roll out, you're going to see a significant increase in bikes in the area, led by, among other things, people hopping on bikeshare to get to Trader Joes.

(There hasn't been, and won't be too much ridership as long as the stations are clustered along Wilson and Clarendon, but as they start to "thicken the trunk", bringing more residences to within a few blocks of a station, I expect to see huge ridership increases).

by Jacques on Feb 23, 2012 5:21 pm • linkreport

Repeating the thought of @Jacques.

I have looked at these plans, and they do plan on closing the entrance to Fairfax off of westbound Wilson. IMO, that connection must be maintained for bicyclists, as Fairfax is a far superior route for cyclists than Wilson.
I hope that the engineers create a well-designed connector for west-bound cyclists. Currently we are forced into the traffic lane for about 30 feet before turning right onto Fairfax; it's an uncomfortable spot.

by Steve O on Feb 24, 2012 11:54 am • linkreport

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