Rockville is a real city with a real downtown. During the 20th Century it was gobbled up by the expanding Washington suburbs, but it has a legitimate historic core. Like many cities, its historic downtown was gutted during the urban renewal days, and is only now recovering. The Rockville Town Square project is a redevelopment that covers a few blocks of the larger downtown area. Although it’s new, and still has a bit of a “plastic” feeling, it’s very well designed and more “real” feeling than many new-built town centers elsewhere.

The project is laid out around a comfortable central plaza. The buildings are all uniform height, giving the project a European feel. Although they were all built at the same time as part of the same project, the architecture of each building is unique, and the styles vary from traditional to modern.

Here are some loose pictures, taken in 2011.

Take a look at this neat urban design feature, from Columbus, Ohio.

High Street is probably Columbus’ best urban street. It runs through most of the city’s best walkable neighborhoods, and has one of the only good bus lines in the region. But there’s a problem: It crosses over I-670, resulting in a block-long overpass that no one could describe as pedestrian friendly.

So the city built a cap above the highway, and topped it with a building lined with shops. The result seems like just another city block.

This is the view from the sidewalk.


If you walk behind the building, you can see the highway rolling underneath.

A: Light rail doesn’t need as much separation as metrorail, and can fit in narrower spaces.

Question: Why do most cities that are building new rapid transit systems use light rail, instead of heavy metrorail?

Someone asked me that question over the weekend. Here is my answer:

It basically comes down to cost and flexibility. Light rail is cheaper and more flexible, so cities use it unless they absolutely need the higher capacity of metrorail.

Heavy metrorail is built to be 100% grade separated all the time. That means nothing ever crosses the tracks. If you want to cross the tracks (as a pedestrian or in a car), you need a bridge or tunnel on a different level so that you can do it while trains are using the tracks simultaneously. This makes metrorail very expensive, and limits where you can put rail lines. In very highly urbanized areas such as downtowns, your only options are basically in a subway or elevated above ground.

Light rail on the other hand works at-grade, which is to say you can allow streets, sidewalks, and pedestrians to cross the tracks. That makes it much cheaper, and much easier to locate/build. You can run light rail along any street you want, basically. This is especially beneficial in downtown areas, where instead of a massively expensive subway or el, you can simply run light rail on the surface. You might opt to give it a dedicated lane or you might opt to run it in a lane mixed with cars, but either way it’s easier and cheaper than a subway/el.

And of course, light rail can run fully grade-separated in a subway or an el if you want it to, it just isn’t required. So if you find that you need a metrorail-level of capacity for part of your line, but not for all of it, you can still use light rail. Metrorail doesn’t offer that kind of flexibility. It has to be grade-separated all the time.

So light rail is generally slower and has lower capacity, but is much easier to fit into cities and is much more affordable. So you would only go to the expense/trouble of building metrorail when you need that very highest level of capacity.

Think of metrorail as being like the transit equivalent of an interstate highway, where there are no traffic lights and there’s not supposed to be anything that impedes traffic. On the other hand, think of light rail as being more like the transit equivalent of a big arterial road, or like Fairfax County Parkway.

Highway overpasses are not usually considered to be beautiful, but sometimes they are. Take a look at these examples from suburban Denver. All the images are via Google Street View, so forgive the quality.

Montgomery and Arlington counties have both been very good at turning their Metro stations into TODs. However, the pattern of how they developed in each jurisdiction varies due to the spacing of Metro stations.

In Arlington, stations are clustered close together in two corridors (Rosslyn-Ballston and Pentagon-Crystal City), so that the TOD areas within each corridor function like neighborhoods within the larger “city” of Arlington. In Montgomery, stations are spaced a mile or so apart, resulting in TOD areas that each function as the downtown for otherwise independent cities, each with its own hinterlands.

Because the TODs in Arlington are clustered together, while those in Montgomery are spaced apart, it’s difficult to get a sense of how they compare to each other. Just how big is Silver Spring, compared to Rosslyn or Ballston, for example?

I set out to answer that question with a series of maps. These maps compare the Rosslyn-Ballston corridor’s 5 Metro station TODs to Bethesda, Friendship Heights, and Silver Spring, all at the same scale. I left out Pentagon-Crystal City, Rockville, and Alexandria, although they might make good additions some time in the future.

First, a reference map. Using Google Maps set at the 2,000 foot view, I colored in the dense portions of each TOD, deleted the surroundings, then put them all on the same page. In this first map, Bethesda and Friendship Heights are shown at the proper distance from each other, in addition to being scaled by area.

Rotating the Wisconsin Avenue axis of Bethesda-Friendship Heights to match Rosslyn-Ballston, and then placing downtown Silver Spring between them, produces 2 almost identical corridors.

Overlaying Silver Spring and Bethesda atop Clarendon shows that if the Maryland TODs were part of Rosslyn-Ballston, they would each would stretch approximately from Court House to Virginia Square.

Barcelona image from SanFranciscoize.

Bus bulbs are a simple and effective way to speed up bus service. The basic idea is that rather than forcing buses to pull out of travel lanes for bus stops, and then make them wait for an opening in traffic before pulling back in when they’re ready to leave, you simply have buses stop in the travel lane, and extend the sidewalk out to the street.

Here is a simple diagram illustrating the concept, and here is a real world example from Russia.

Sidewalks extensions are relatively cheap and easy to build compared to many other things. Nonetheless, it takes months of planning and a fair amount of funding for public agencies to do them. Plus, of course, there’s the accompanying disruption that comes with construction.

The attached image shows an easier, cheaper, and faster alternative. It’s a pre-fab unit installed in Barcelona, Spain. It accomplishes all the same goals as a regular sidewalk extension would, but is easier in just about every way.

Without having actually used one of these or seen one up close, the major downside appears to be that the pre-fab unit isn’t as pretty as a real sidewalk. It looks a little bit cheap and tacked on. Which of course it is; that’s the idea.

Would we want these on Pennsylvania Avenue or in front of the White House? Probably not. But they might very well be a reasonable way to make transit improvements on less monumental streets.

	Proposed mixing zone design.
	A possible warning sign.

It’s very exciting that DDOT is advancing the L Street cycle track. When complete, it will be by far the best way to bike from west to east through downtown DC.

Unfortunately, the design of the cycle track doesn’t completely separate bicyclists from cars, which is usually the main point of cycle tracks. DDOT is concerned about narrowing L Street too much, and about potential left-hooks. So the design of the cycle track calls for cars planning to turn left onto cross streets to cross over the cycle track, and then turn left from a turn lane located between the curb and the cycle track.

Although it’s unfortunate that this design doesn’t eliminate mixing, it’s probably a good experiment. Cycle track design is still an evolving field in the United States, so it makes sense to try different techniques. If this doesn’t work, DDOT can theoretically go back in a few years and fix it. Meanwhile, we’re getting at least a pretty good solution right away.

But since the point of cycle tracks is to separate bike and car traffic from each other, and since this plan doesn’t fully accomplish that, DDOT will need to be serious about its signage and pavement markings. To make this work, they must do everything possible to send an un-missable message to car drivers that they should expect to encounter and yield to bicyclists on L Street.

One good thing they are doing is painting part of the bike lane green. That’s a good way to increase visibility and remind drivers to watch for cyclists. However, they aren’t going to paint the most crucial mixing area – where cars cross over the bike lane. That omission should be addressed. DDOT should modify their plans to include green paint in the cross-over area.

Finally, there will need to be excellent, colorful, signage warning drivers. The standard federal sign instructing turning drivers to yield to bikes isn’t adequate for a cycle track situation, where full separation is expected. Other options, such as this or the one pictured at right, should be considered.

DDOT should be commended for innovating a workable solution to a difficult context, but if complete separation isn’t possible then they should do everything they can to make sure drivers know they are crossing over a major bike facility. The mixing zone should be painted green, and colorful signs should be installed.

Proposed amphitheater. Design by OLIN + Weiss/Manfredi.

The National Mall is not a perfect space. Although millions of people visit it each year, many sections are oversized and underused. It’s poorly integrated with the surrounding city, and its aging components are in need of maintenance. What can be done?

No one would propose demolishing the Mall, or seriously changing its basic character, but clearly there is room for improvement.

The Trust for the National Mall agrees. They sponsored a design competition to rethink 3 important sections of the Mall: Constitution Gardens, the Washington Monument grounds, and Union Square. The winning entries are filled with interesting ideas.

Constitution Gardens

Design by Rogers Marvel Architects + Peter Walker and Partners.

Many Washingtonians feel that Constitution Gardens is the best part of the Mall already. Certainly it’s the most unique, with its informal pond and romantic pathways. The winning design, by Rogers Marvel Architects + Peter Walker and Partners, will build on the gardens’ strengths to make it even better.

They propose to introduce a new pavilion at the east end of the existing pond. This pavilion would become the centerpiece of activity in the garden. It would contain a restaurant and a dock for model boating. In the winter, the eastern section of the pond would be used for ice skating.

These additional active uses are good additions, although one wonders if another ice skating rink can survive so close to the existing rink at the Sculpture Garden.

One negative aspect of this plan is that it actively turns its back on the street. It proposes to raise new hills along Constitution Avenue in order to “provide separation” between the park and downtown. This is entirely the wrong approach, and will contribute even more to the segregation of the city’s cultural amenities from the city’s residents.

Washington Monument grounds

Design by OLIN + Weiss/Manfredi.

In contrast to Constitution Gardens, the Washington Monument grounds are probably the worst section the Mall. The giant grass lawns are not destinations to anyone but a few softball players. Rather, they are long, empty voids that must be traversed.

The poor condition of the grounds is even more unfortunate because they are the geographic center of the monumental core. In theory this should be the most heavily-built and formal area of the Mall, but in reality it is the least.

The winning entry for this section, by OLIN + Weiss/Manfredi, is disappointing in its scope. Rather than address the fundamental deficiencies with the grounds as a whole, the design focuses closely on the southeast corner and largely ignores the rest.

To the designers’ credit, what they have proposed is excellent. They would replace the afterthought that is the existing Sylvan Theater with a wonderful new grass amphitheater. It would blend seamlessly with the surrounding landscape, would face and help to frame the Washington Monument, and would vastly improve the theater experience in every way.

They also propose a cafe and bookstore, to be built into the side of a small hill so that they appear as one with the rolling landscape. These are good additions that will improve the edge condition between park and city, and the proposed architecture is both appropriate and totally unique.

Union Square

Design by Gustafson Guthrie Nichol + Davis Brody Bond.

Better known as the Capitol Reflecting Pool, Union Square suffers from many of the same problems as the Washington Monument grounds. It’s visually impressive, but usually empty. There’s not much reason for people to go except to pass through, and its monumental components are so oversized that they are a barrier to walking.

The winning design, by Gustafson Guthrie Nichol + Davis Brody Bond, does much to improve the situation.

They propose reducing the size of the reflecting pool and carrying additional pathways through the site, creating new connections with the Smithsonian area to the west.

They also propose to narrow Pennsylvania and Maryland Avenues, and to convert them from parking lots to more pedestrian-friendly streets.

Unfortunately, the garden areas north of Pennsylvania Avenue and south of Maryland Avenue are afterthoughts in this proposal. It would have been nice to see a new building on the north end of the site, mirroring the location of the US Botanical Garden. That area is a nether-zone between the Mall and Senate Park, and would be more valuable as the site for a future museum.

Next steps

The Trust for the National Mall does actually intend to build these designs. Fundraising will begin soon, and the first ribbon-cutting could take place as early as 2016.

That’s good news.

Overall, these ideas would improve the National Mall. It would still be an imperfect space, poorly connected to the living city around it. But it would, for the most part, be better than it is today.

 Cross-posted at Greater Greater Washington.
 
 
 

Germantown Town Center is not a triumph of urbanism. Of all the suburban “new downtowns” built in the Washington region in the last 20 years, Germantown’s is probably the least impressive. It is essentially a suburban strip mall, anchored by a grocery store, with a handful of liner shops fronting onto a short “main street.” It’s surrounded by suburban-style apartment complexes, and has a library, a nice performing arts center, and a whole ton of surface parking lots.

And soon it will have a park. And actually, the park is pretty interesting.

Most of the parks in Germantown are either nature preserves, athletic fields, or playgrounds. There is a small town square, but nothing like DC’s Meridian Hill Park. Nothing where residents might visit on a Sunday afternoon to sit on a public bench, read a book, and watch the passers-by. No central community gathering place that hosts picnics, frisbee, and romantic strolls.

Thus the new central park, which broke ground last week. It will have a formal layout, with sculpted lawns, stone-faced trails, and a central pergola.

Park site plan.

The park is a nice enough design, and it’s very encouraging to see planning in a place like Germantown (which has almost 90,000 residents) move forward towards a more livable and sustainable urban model.

One major criticism of the park, however, is that it fails to produce an urban room. The best urban public spaces have clear walls that frame and help to define the space. They’re surrounded by buildings that front onto them, providing a sense of enclosure as well as activity and safety, and from which pedestrians can move freely. More than anything else, this is what separates the character of a good urban park from that of a rural path through the woods. A walk through the forest is a nice experience, but a different one.

Unfortunately, Germantown’s new central park is surrounded by parking lots, wide highways, and the backs of randomly placed buildings. Rather than providing a seamless connection to every surrounding property, most of the park’s boundary is blocked to pedestrians, who will have to enter and exit from designated walkways. There will be scant enclosure, and little if any sense that this is the center of Germantown.

Park location.

Internally this will be a nice enough park, and it is undeniably a step forward in Germantown’s urban design. But the same suburban conservatism that has hampered Germantown Town Center since its inception is also at work here. Neither the town center nor the park will live up to their potential as long as so many concessions to suburbanism are included in their design.

Sooner or later, the half measures will no longer seem impressive.

Maryland is beginning to take the idea of grass track beds for light rail very seriously. For years renderings of the Purple Line have shown grass tracks in some sections, and now the state has installed an actual grass track as a pilot project in Baltimore.

Actually, they are testing a variety of green track beds, grass being only one of the options. They’re also looking at sedums, another type of ground cover plant that is often used on green roofs, and which use less water and are easier to maintain than regular grass.

Here are some pictures of the test project:

MTA has also been repainting its light rail cars with new color schemes in recent years. This is apparently part of a refurbishment project for its oldest railcars. The original blue stripe livery is slowly disappearing, as cars are repainted with the more colorful 2010 and 2011 liveries.

Original 1992 livery.	~2003 livery.
~2010 livery.	~2011 livery (left).