Greater Greater Washington

Posts in category Public Spaces

Five new murals that add life to NoMa and Truxton Circle

New murals are brightening NoMa and Truxton Circle. Here's where you can find them.


Fresh Cut Barber Shop at North Capitol and Bates Street NW. All photos by the author unless otherwise noted.

One is on North Capitol and Bates St. NW, and another on the corner of Florida Avenue and Q St. NW.


Fiddlehead's Salon at Florida and Q NW.

Another is part 5x5, a DC Commission on the Arts and Humanities initiative to develop public art. It's painted on a retaining wall along First Street. Both its bright primary colors and message, "Home Is Where the Heart Is," make First and N NE, which used to be pretty bland, come alive.


First and N NE.

Two more, which Art Whino and JBG Companies collaborated to commission, help with the job:


First and N NE.

JBG has plans to redevelop each of these the two buildings, but the murals spruce them up in the meantime.


First and N NE. Photo by BeyondDC on Flickr.

DC Public Works supports street and performance art throughout the city as a way of showcasing local artists, and in some cases as a method for preventing unwanted graffiti.

Throughout the region, murals tell stories about their neighborhoods and their history and values. Rather than letting older and unused buildings simply fall into disrepair, recreating and enlivening them with artwork makes them new again.

Bollards shape bicycle tracks in the snow

Snow is not just fun or a chore to shovel, but also a planning tool in the way it visually reveals the paths people take as they walk, bike, or drive. Jeff Miller captured this fascinating photograph of how bicyclists' many paths converge on a few points as they pass through the bollards on Pennsylvania Avenue near the White House.


Photo by Jeff Miller on Twitter.
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Events roundup: Changes are coming

I-66, Capital Bikeshare, and Prince George's zoning will all be changing in the near future. Have you weighed in? Plus, learn about dams, bikeway design, and more in this week's events.


Photo by thisisbossi on Flickr.

Tolls and lanes for I-66: Virginia is considering tolls for people driving alone on I-66, along with new lanes outside the Beltway. State transportation officials are holding a series of meetings this Monday to Thursday around Oakton, Centreville, Haymarket, and Fair Oaks, all from 6 to 8:30 pm.

Rewrite Prince George's zoning: Prince George's County is rewriting its zoning code for the first time in 50 years, which will have a major effect on future development. Three listening sessions, Tuesday in Riverdale, Wednesday in Fort Washington, and Thursday in Landover. All meetings are 6-8 pm.

Those damn dams: Senator Al Franken will host a screening of the movie DamNation on Tuesday, January 27, 5:30-8:30 pm at the US Capitol Visitor Center. This documentary explores how the US has changed its attitude towards dams from a source of national pride to environmental awareness. A panel discussion will follow the film. RSVP is requested.

Talk bikeshare's future: Help shape the future of Capital Bikeshare at an open house this Wednesday, January 28, 6-8 pm at the Marin Luther King Jr. Library at 901 G Street NW. Officials will discuss a possible price increase and future expansion. There will also be a trivia table and fun facts about bikeshare on display. You don't want to miss it.

The right way to make bikeways: Bill Schultheiss of Toole Design Group will speak about his experience building bike lanes in several US cities and his observations from abroad. The talk is Thursday, January 29, 6 pm at the Downtown BID, 1250 H Street NW Suite 1000. RSVP by January 28 to attend.

Do you know of an upcoming event that may be interesting, relevant, or important to Greater Greater Washington readers? Send it to us at events@ggwash.org.

The Air and Space Museum needs a new skin

In the four decades after it opened, the National Air and Space Museum has become one of Washington's most well-loved attractions. Its building hasn't aged so well.

The window walls are outdated, skylights leak, the mechanical systems are dying, and the terraces are leaking into the basement car storage. But much worse than that, the stones that clad the building are bowing and cracking, which threaten to make it uninhabitable.


Photo by Terry (α) on Flickr.

Usually, there's nothing wrong with getting wrinkly at 40, but here, the 12,000 stone panels are pretty much the only thing keeping water out of the building. When they deform, they expose the building to more and bigger leaks. They could also break and fall onto someone.

We think of stone as unfailingly solid. But, like in most buildings built after 1900, the stones at the Air and Space Museum form a veneer that carries no weight. This approach has worked quite well in most cases, but if the stones are too thin, or installed the wrong way, they can deteriorate.

When thin stones fail

The museum's stones are 5 feet long, 2½ feet high, but only 1¼ inches thick. Beginning in the 1950s, engineers and architects tried to apply stone as thinly as possible to make buildings more cost-efficient.

Things went well for denser stones like granite and on buildings in warmer climates. But beginning in the 1970s, spectacular failures started to occur when soft marble covered a building in a cold climate, like Finlandia Hall in Helsinki or the Standard Oil Building in Chicago.

The stones started bowing due to a phenomenon called "thermal hysteresis."

Imagine a slab of stone sitting in the sun. One side gets warm from the sunshine, while the other does not. The sunny side expands and contracts differently from the other. If the stone is too thin, the flexing can damage the crystalline structure.


The warping is visible when the sun hits the panels at a low angle. Image from Google Maps.

Stone comes to the National Mall

The Air and Space Museum is clad in a stone called "Tennessee pink marble," although it's technically not marble, but a particularly crystallized form of limestone.

John Russell Pope introduced the stone to the National Mall with his 1941 National Gallery of Art. The warm color and faintly glittering texture was a welcome alternative to icy marble, dull limestone, and harsh granite. Because the National Air and Space Museum was across from the National Gallery, the Commission of Fine Arts pushed its architect, Gyo Obata, to match it.


The south side elevation shows more damage where the tiles are more exposed to sun.

But Pope used stones four to eight inches thick and installed them in a heavy and redundant way. IM Pei's stonework on the 1978 East Wing also had serious problems, but those stones were 3 inches thick and the problems primarily came from the way the stones hung on the building, which the Gallery was able to fix.

That will not be possible at the Air and Space Museum.


Section drawing of how the stones sit on the steel frame.

Too thin is just the beginning

The panels are pinned together end to end through holes drilled through the stone. As the panels warp at different rates, stainless steel rods apply enormous pressure to an extremely thin layer of stone. The brittle stone is liable to crack and even shed pieces.

The stones also sit on metal rails connected directly to the steel frame, so unlike with the National Gallery buildings, they're subject to the frame's motion. Already by the 1980s the Smithsonian had to widen the joints between the stones to reduce damage.

As the stone cracks, an inner cavity opens to the elements. Normal buildings have a membrane or second wall to prevent moisture from moving through the outer walls. Here, the only protection is foam insulation sprayed onto the inner face of the stone.

Finally, between the stones and walls of the exhibition halls is a large open space that carries used air back to the ventilation system. This means that the thin stones are the only thing between inside and outside. Ironically, reconstruction architect Larry Barr remarked that the constant airflow was probably the only reason there wasn't severe water damage or a mold problem. Moisture could simply never accumulate with the continuous flow of dryer air.

Some solutions are obvious, others require tough choices

The building needs a new facade, new windows, new equipment, and repairs to the terraces. You shouldn't have to renovate a building, let alone a monumental one so soon, but the renovation offers the opportunity to correct 40-year-old mistakes and build for at least another hundred.

In the 1970s, inflation encouraged cost-cutting and buildings were adding elaborate mechanical systems long before their performance was understood. Sustainability was not yet a concern for architects. The museum, which had stalled for two decades, was then rushed to be ready for the 1976 United States Bicentennial and opened days before the 4th of July.


Earlier design for the museum. Image from the Commission of Fine Arts / HOK.

But building technology has improved a lot, so there is a silver lining. Fixing a relatively typical problem like the terrace waterproofing affords the opportunity to replace it with more proven systems, brush up the planting, and improve circulation around the site.

Much better glass technology including durable films to block unwanted radiation, newer seals, and better insulation would make for a better experience on cold days and muggy afternoons. The design team is even considering installing solar panels onto the roof, reducing carbon footprint and partially shading some of the skylights.

Other projects, such as redesigning the entrance for security purposes, offers the opportunity to make the building's entrance more engaging. A similar level of attention could be paid to the Independence Avenue side of the museum, which stands out as particularly pedestrian-unfriendly.

The big decision is how to replace the stone and its supporting system. The museum asked Quinn Evans Architects to prepare for a reconstruction of the exterior, in four options: thicker Tennessee stone, sturdier pink granite, a ceramic system, or titanium. The latter two would bring new materials to the Mall and disrupt the match between this and the National Gallery, but would be more resilient and arguably interpret the building's content better than stone.


Four possible options for replacing the stone.

The four options are deceptive, because of the wide range of textures possible with each material. Titanium can come in flat, smooth panels, or it can be scalier, like the titanium used on the Guggenheim Bilbao. Ceramic systems, too, can take a wide range of textures and forms. The options go beyond just copying the 2.5' by 5' stones as the rendering above suggests.

In any event, it makes little sense to fret over preserving the architecture. It is not a universally loved building. In a chat about America's landmarks, Stanley Tigerman characterized it as "not even architecturally interesting," pointing out that the building's content occupies a more prominent role in the memory of Americans than the architecture itself

Perhaps a little bit more ambition and thought can mean we needn't repeat this renovation in 2055.

What to watch for in the 2015 Virginia General Assembly

The Virginia General Assembly's 2015 session kicks off today in Richmond. Smart growth and environmental advocates are gearing up for a busy, if short, session. While things evolve quickly at the beginning of any legislative session, there are already several issues and bills to look for that may impact smart growth in Northern Virginia.


Photo by Virginia Guard Public Affairs on Flickr.

Transit funding

Because legislation over the past four years didn't make transit a priority, it faces big funding shortfalls. 65% of Virginia's population and gross state product lie within the urban crescent (from Northern Virginia to Hampton Roads), and with an aging population in rural areas, transit needs are growing.

Yesterday, Governor McAuliffe announced a package of transportation initiatives including a proposal to shift $50 million per year from ports, aviation, highways, and freight rail to transit. This helps, but isn't a long-term solution.

Transportation policy reform

Advocates expect that bills to reform the Public Private Transportation Act (PPTA) will try to prevent future disastrous project decisions, like Route 460 out of Hampton Roads, which wasted $300 million in taxpayer funds without having permits in hand. This year, proposed reforms to the PPTA include requiring better risk analysis and greater legislative oversight.

Highway advocates hostile to transit have tried for many years to make "congestion reduction" the main criterion for selecting transportation projects. Last year, the smart growth community won important amendments to a bill, HB2, which set more balanced criteria to give transit projects a fair chance at funding.

Unfortunately, transit opponents are back this session with bills to force VDOT to evaluate Northern Virginia projects solely under the congestion reduction standard. This would force officials to ignore the benefits of transit for moving more people, providing an effective commute option, reducing air pollution, promoting smart growth development, and maximizing walk, bike and transit trips.

Bicycle and pedestrian priorities

Legislators are proposing bills to improve safety for bicyclists and pedestrians, including anti-dooring bills, bills to make it easier to safely and legally pass cyclists with a 3-foot buffer, and bills to require stopping for pedestrians in crosswalks.

Another bill would ensure localities don't lose state funding if they make bike improvements on local streets. Today, changing road from two lanes each way to one lane each way, plus a center turn lane, plus bike lanes (as Fairfax County did with Lawyers Road) could reduce a jurisdiction's funding under the state formula.

Standards for Uber, Lyft, and other services

Ride-hailing services have hit the scene across the country, offering new options for getting around without owning a car. States are addressing how to properly regulate these services, and Virginia is no exception. Issues include insurance, background checks for drivers, access for the disabled and those without credit cards, and use of hybrid or other high-efficiency vehicles.

Threats to land conservation

Virginia's very successful Land Preservation Tax Credit program is facing significant cuts, even though it has effectively helped Virginians to voluntarily conserve tens of thousands of acres in farms and forests, and helped communities reduce sprawl and the costs of public infrastructure.

Opponents of land conservation are also pushing legislation designed to undermine the conservation easement program, impacting the right and ability of private landowners to conserve their land. Expect to see smart growth and conservation groups across the state partner to defend this program.

Potomac bridges

It seems that each year brings new bills pushing for new highways across the Potomac far upstream from the American Legion Bridge. New bridges have the potential to impact Great Falls, Reston, and eastern Loudoun, fueling more sprawl and diverting funds need for investing in transit and fixing the American Legion Bridge. Each year, we've won bipartisan support to stop these bills. We'll see if they pop up again.

Specific details on particular bills will become available on the legislative system as they are filed and published. We'll follow up with bill numbers, details, and links in upcoming posts as the legislative session continues.

Here's what Dupont's abandoned streetcar tunnels look like

The old streetcar tunnels under Dupont Circle have sat vacant and abandoned for years. A group of arts organizations has been trying to reactivate the tunnels, and recently signed a 5-year lease with DC. This video from PBS Digital Studios gives you a sneak peek at the space.

Making the space work will be a difficult task. The tunnels need a lot of work, and underground spaces can pose challenges like water getting in. What do you think of the space, and the possibility of it seeing use again one day?

How to tell the difference between streetcars and light rail

There is much confusion over what separates streetcars from light rail. That's because there's no single easy way to tell, and many systems are hybrids. To tell the difference, one has to simultaneously look at the tracks, train vehicles, and stations.


San Francisco's Muni Metro runs both in a dedicated subway and on the street in mixed traffic.
Is it a streetcar or light rail system? Photos by Matt Johnson and SFbay on Flickr.

It's hard to tell the difference because streetcars and light rail are really the same technology, but with different operating characteristics that serve different types of trips.

The difference, in a nutshell

Theoretically light rail is a streetcar that, like a subway or el, goes faster in order to serve trips over a longer distance. But what does that mean in practice?

There are several features of tracks, vehicles, and stations that both streetcars and light rail sometimes have, but which are generally more common on light rail. Thus, although there's no single separating test that can tell the two apart with 100% accuracy, it's usually possible to tell the difference by looking at several factors simultaneously.


Image by the author.

Let's look at each of those factors, one by one.

Lanes and tracks

It's a common misconception that streetcars always run in mixed traffic with cars, while light rail has its own dedicated track space. That's often true, and it's such a convenient and easy-to-understand definition that I've been guilty of using it myself. But it's wrong.

There are too many exceptions to that rule to rely on it completely. Sometimes (though rarely) light rail lines run in mixed-traffic, and there are plenty of streetcars with their own right-of-way. Some streetcars even have subways.

Compare Sacramento's mixed-traffic light rail with Philadelphia's streetcar subway, for instance:


Left: Sacramento light rail in mixed traffic. Photo by Flastic on Wikipedia.
Right: Philadelphia streetcar in a subway. Photo by John Smatlak on Flickr.

In fact, practically every mixed-traffic streetcar has at least a short section of dedicated track. That's true in Atlanta, Seattle, Tucson, even DC. Those streetcar lines don't suddenly become "light rail" for one block just because they have a dedicated lane somewhere. It's just not that simple.

And some streetcars have long stretches with dedicated lanes. Toronto's massive streetcar network has several dedicated transitways, and DC is planning one on K Street.


Left: K Street transitway. Image from DC Streetcar.
Right: Toronto's Saint Clair transitway. Photo by Sean Marshall on Flickr.

There are too many streetcars with dedicated lanes for that to be a reliable indicator on its own. Too many lines that mix dedicated and non-dedicated sections. Certainly it's an important data point; certainly it's one factor that can help tell the difference. But it's not enough.

An even simpler definition might be to call anything with tracks in the street a streetcar, and anything with tracks elsewhere light rail.

But that's not reliable either, as Portland and New Orleans illustrate:


Left: Portland light rail. Photo by BeyondDC.
Right: New Orleans streetcar. Photo by karmacamilleeon on Flickr.

Salt Lake City muddies the water still further. Its "light rail" mostly runs in the street, while its "streetcar" runs in an old freight train right of way, almost completely off-street.


Left: Salt Lake City light rail. Photo by VXLA on Flickr.
Right: Salt Lake City streetcar. Photo by Paul Kimo McGregor on Flickr.

Vehicles and trains

If tracks on their own aren't enough to tell the difference, what about vehicles?

It's tempting to think of streetcars as "lighter" light rail, which implies smaller vehicles. Sometimes that's true; a single DC streetcar is 66 feet long, compared to a single Norfolk light rail car, which is over 90 feet long.

But not all streetcars are short. Toronto's newest streetcars are 99 feet long.


Toronto streetcar. Photo by Canadian Pacific on Flickr.

In fact, many light rail and streetcar lines use the exact same vehicles. For example, Tacoma calls its Link line light rail, and uses the same train model as streetcars in Portland, DC, and Seattle, while Atlanta's streetcar uses the same train model as light rail in San Diego, Norfolk, and Charlotte. And Salt Lake City uses the same train model for both its streetcar and light rail services.


Left: Tacoma light rail. Photo by Marcel Marchon on Flickr.
Right: Portland streetcar. Photo by Matt Johnson on Flickr.


Left: San Diego light rail. Photo by BeyondDC.
Right: Atlanta streetcar. Photo by Matt Johnson on Flickr.

And although streetcars often run as single railcars while light rail often runs with trains made up of multiple railcars, there are exceptions to that too.

San Francisco's Muni Metro and Boston's Green Line definitely blur the line between streetcar & light rail, perhaps more than any other systems in North America. Some might hesitate to call them streetcars. But they both run trains in mixed-traffic with cars, and some of those trains have multiple railcars.

Meanwhile, many light rail systems frequently run single-car trains, especially during off-peak hours.


Left: Norfolk light rail with a single car. Photo by BeyondDC.
Right: San Francisco streetcar with two cars. Photo by Stephen Rees on Flickr.

Stations offer some help, but no guarantee

Light rail typically has bigger stations, while streetcars typically have smaller ones. A big station can sometimes be a good clue that you're likely dealing with light rail.

For example, look at Charlotte and Portland:


Left: Charlotte light rail. Photo by BeyondDC.
Right: Portland streetcar. Photo by BeyondDC.

But that's only a general guideline, not a hard rule. Just like tracks and vehicles, there are many exceptions. Light rail often has small stops, and streetcar stations can sometimes get pretty big (especially when they're in a subway).

This light rail stop in Norfolk is smaller than this streetcar stop in Philadelphia, for example:


Left: Norfolk light rail. Photo by BeyondDC.
Right: Philadelphia streetcar. Photo by BeyondDC.

Stop spacing and route length

Probably the most reliable way to tell streetcars apart from light rail is to look at where the stations are located. Light rail lines typically have stops further apart from each other, on lines covering a longer distance.

This chart explains the difference:


Image from Jarrett Walker.

This is the definition transit expert Jarrett Walker favors, and if you have to pick just one or two factors to consider, stop spacing and route length are the best.

But even this is no sure way to categorize all lines as either streetcars or light rail. It might be easy to tell the difference between something with stops one block apart (theoretically streetcar) versus stops two miles apart (theoretically light rail), but what if the stops are 1/4 mile apart? Or what if the gaps aren't consistent? There's no clear place to draw the line.

Furthermore, Walker's graphic itself illustrates exceptions to the rule. The top line shows a light rail route with stops close together downtown, the third line shows a streetcar with some sections that have far-apart stations, and the fourth line shows a very long streetcar.

There are certainly plenty of real-life examples of those exceptions. Before Arlington, VA cancelled its Columbia Pike streetcar, DC and Arlington were considering linking their streetcars with a bridge over the Potomac River. Had that happened, there might have been a mile-and-a-half between stops.

Certainly station spacing and route length provide a convenient general rule, but only that. There's no hard boundary where everything to one side is streetcar, and everything to the other is light rail.

To really know the difference, look at everything

There are seven factors that light rail usually has, but that streetcars only sometimes share: Dedicated lanes, off-street tracks, bigger vehicles, multi-car trains, longer routes, bigger stations, and long distances between stations.

No single one of them provides a foolproof litmus test, because sometimes streetcars have each of them, and sometimes light rail doesn't. But if you look at all seven together and determine which direction the majority of a line's characteristics point, over the majority of its route, then you can usually sort most lines into one category or the other.

For example, DC's H Street line fits neatly into the streetcar category, because it runs in the street almost totally in mixed traffic, with small vehicles on single-car trains, along a short route that has frequent, small stations. Even if DDOT builds the K Street transitway and a dedicated-lane streetcar on Georgia Avenue, the majority of the seven factors will still point to streetcar.

On the other end of the spectrum, Seattle's Central route is squarely light rail. It has a dedicated right-of-way that's often off-street, uses large 95 foot-long vehicles that are usually coupled into multi-car trains, along a long route with infrequent stations.


Left: Seattle light rail. Photo by Atomic Taco on Flickr.
Right: DC streetcar. Photo by BeyondDC.

But even then not every system is crystal clear. San Francisco's Muni Metro, Philadelphia and Boston's Green Lines, and Pittsburgh's T, for example, all have some segments that look like classic streetcars, but also some segments that look like classic light rail. These networks defy any characterization, except as hybrids.

It's a feature, not a bug

The fact that it's hard to tell the difference is precisely why so many cities are building light rail / streetcar lines. The technology is flexible to whatever service characteristics a city might need.

You can use it to build a regional subway like Seattle, or you can use it for a short neighborhood circulator like DC's H Street, or anything in-between. And perhaps even more importantly, you can use it to mix and match multiple characteristics on the same line, without forcing riders to transfer.

That's why many of the most successful light rail / streetcar systems are the hardest ones to categorize as either / or. They match the infrastructure investment to the needs of the corridor, on a case-by-case basis, and thus have some sections that look like light rail, and others that look like streetcar.

That's not muddied. That's smart. That's matching the investment to the need, which is after all more important than a line's name.

Cross-posted at BeyondDC.

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