Posts about Road Connectivity

The connectivity standards reformed a key mistake in suburban development: building neighborhoods composed primarily of cul-de-sacs. In many neighborhoods, there's just one way in and out for any homeowner, to one or maybe two major arterial roads.

While this gives many homeowners the ability to live on a quiet street, it creates problems for everyone. With few entry and exit points, all the traffic gets focused on single intersections at the arterials, causing significant congestion. Kids can't walk or bike to school or even friends' houses when the only route involves going out to the busiest part of the neighborhood and along a wide road designed for high-speed traffic.

And it costs taxpayers. These neighborhoods are very expansive to plow for snow and time-consuming to navigate for ambulances and fire trucks. Subdivisions in Virginia had to wait days or weeks for plowing during the major snows last year because of the way the plows had to constantly backtrack, and people couldn't get out of their neighborhoods without any alternate routes.

Older suburban areas still primarily comprise single-family houses while providing a grid that spreads traffic around and offers many safe routes for non-motorized users. Areas like Columbia, Greenbelt and Reston win constant plaudits for designing suburban areas that lack these shortcomings, with paths to walk and bike that also build community.

The connectivity rules revolved around a simple premise: Once a developer builds a subdivision, VDOT (except in a few counties) then takes over responsibility for maintaining and plowing the roads. Therefore, they should be able to require certain standards to avoid developers pushing all the costs off onto the taxpayer. The General Assembly in 2007 authorized a change, and Virginia briefly jumped far ahead of most states with this progressive policy.

Last week, however, the Commonwealth Transportation Board, a policymaking body appointed by the Governor, voted to drop the old standards, especially the "Connectivity Index" which created a score based on the degree to which a street network was connected or isolated.

Instead, they set some rules for the number of connections out of a subdivision and onto main streets. A development of 200 homes needs 2 connections, though 1 can be a "stub end" road which connects to an as-yet-undeveloped area. Each additional 200 homes will only require one additional connection. It's better than nothing, but still means a new 200-house development can have just 1 way in and out.

Also, a subdivision can add a "collector road" which gives double credit if that road is part of a county transportation plan. So a developer could build 400 houses, all on cul-de-sacs off one major road through the center, and connect that road only at 2 points to major arterials. A typical suburban house can generate about 10 car trips per day, so there will be 4,000 turning movements onto and off of those 2 arterials every day. It's a recipe for major traffic that will harm every other resident who uses those roads.

While Virginia is weakening rules to create better road networks in new suburbs, it's neglecting established areas in favor of greenfield development and traffic-inducing megaprojects. Governor McDonnell and Transportation Secretary Sean Connaughton have made it clear they don't want to contribute to the Silver Line Phase II, even if the federal government, Fairfax, and Loudon all put in more money.

Meanwhile, but McDonnell and Connaughton are eagerly borrowing money to build large freeways like the damaging bypass around Charlottesville or to push an Outer Beltway. Much of the region's future growth will happen in Tysons Corner, but it's not getting transportation improvements it needs. And transit along the Route 1/Richmond Highway corridor is nowhere on the agenda.

Virginia could get far more bang for its precious transportation buck by focusing on local street connections, and most of all repairing crumbling roads and bridges. Instead, the McDonnell administration seems bent on repeating the mistakes of the 1950s: building unsustainable transportation networks at the periphery while letting a more central economic engine sputter. Then, it was center cities across America; now, it's Arlington, Alexandria and Tysons Corner which state officials are looking past instead of toward.

Tonight is an important meeting where Virginia residents can speak up about priorities. VDOT is having a public meeting to hear input on its 6-year priorities tonight, at the VDOT Northern Virginia District Office, 4975 Alliance Drive in Fairfax. Sadly, VDOT doesn't seem to think it's a priority to locate a meeting near Metro. An open house format starts at 6, and presentations by local officials at 6:30 followed by public testimony.

Bob Chase's Northern Virginia Transportation Alliance, a group funded by greenfield developers in Virginia to lobby for roads that would feed suburban development on their land, has been pushing its members to attend and push for an Outer Beltway. Chase even argued, with an apparent straight face, that new highway lanes were more important than repairing crumbling bridges during a round of news stories last week concerning the dire condition of the nation's infrastructure.

It's important to get more residents who support good road connectivity, local street improvements, repairing crumbling infrastructure, pedestrian and bicycle projects, and local transit improvements to counter the sprawl lobbyists. If you can't attend, you can also send in written testimony at this Coalition for Smarter Growth page.

Regardless of the final path that future development will take in the neighborhood, all three proposals would deck the CSX rail line to extend Maryland Avenue SW, include some degree of infill development, and vastly improve the connection between Benjamin Banneker Park and the Southwest Waterfront.

Rehabilitation

Under the Rehabilitation proposal, future development of the Ecodistrict would focus on retooling the vastly inefficient 60's and 70's era federal buildings that currently dominate the site. This would primarily involve a vast upgrade of the heating and cooling systems present in many of these buildings, enhancing stormwater management, and increasing on-site electricity production and conservation.

Some of the buildings may also start to incorporate residential and commercial uses in order to enhance the diversity of the neighborhood. While no buildings would be removed under this option, it would cut away the Department of Energy's overhang that currently cuts off views along 10th Street of the Smithsonian Castle to the north.

Furthermore, it would enhance the current network of streets by adding a number of new intersections and enhancing the neighborhood's connectivity.

Redevelopment

The Redevelopment proposal includes many of the elements of Rehabilitation, such as the energy-efficiency and stormwater elements, but it goes a farther in some key respects. Instead of just cutting out the 10th Street overhang, this plan would completly demolish the Department of Energy's James Forrestal building, replacing it with a number of new structures.

The great appeal of this plan is that it will open up brand new views of the Washington Monument from Virginia Avenue SW. The plan also seeks to deck over a portion of I-395 between 10th Street and 9th Street, increasing the number of potential buildings along the corridor and partially removing the unsightly highway from view.

This Redevelopment proposal also goes the farthest to enhance the connectivity of the street grid by breaking up the Department of Energy superblock and adding the greatest number of new intersections to the neighborhood.

Repurpose

NCPC's final proposal is the simplest. It focuses on repurposing several federal buildings to new uses. The buildings with the most potential include the nearby US Postal Services Library, the General Services Administration Building, and the FAA's Orrville Wright Building.

NCPC believes that simply repurposing these buildings and renovating others to more efficiently use their space could yield up to another million square feet of space in which to add neighborhood amenities.

No plan has been set in stone, and any future development will likely include bits and pieces from any or all of these proposals. All seek to enhance the neighborhood by adding new amenities, including restaurants, retail, and cultural destinations that will not only draw new residents to the area but also pull some of the millions of tourists away from the National Mall and towards the cultural amenities of our fair city.

This pattern of development is largely a product of car-oriented design. It often has the effect of creating fast-moving, unimpeded roadways between superblocks. This is inappropriate for an area adjacent to an urban rail station.

Compared to places like Columbia, these superblocks are certainly not the most car-oriented. The blocks on either side of East-West Highway between Georgia Avenue and Colesville Road host a mix of residential, office, and retail in close proximity. But because of the variety of walking destinations and adjacent transit center, the lack of transportation permeability inherent in a superblock is even more inappropriate here than in an office park in the exurbs.

East-West Highway has wide sidewalks along the north and most of the south side. There aren't many crosswalks, but they are generally up to the high standards of other crosswalks in downtown Silver Spring, which are signalized and well-marked. But because they are so few and far between, they force pedestrians to take circuitous routes to destinations along East-West Highway.

On the south side of the street, a narrow sidewalks runs along a steep hill with no fence or guardrail between the pedestrian and a potentially nasty spill. On the north side of the street, several parking garage driveways act almost like street intersections, only without three-way crosswalks. Drivers pouring out of these garages at rush hour often do not yield pedestrians the right-of-way, as they should, which adds to the treacherousness of walking this stretch.

The roadway itself, however, is a long, wide, virtually unimpeded straightaway. The 30 mph speed limit hardly matches the road design, and there are no speed cameras to discourage unsafe speeds. This further endangers pedestrians, even at marked crosswalks.

To make matters worse, construction has inconveniently closed sidewalks on several occasions. On the corner of East-West Highway and Blair Mill Road, a notorious sidewalk closure has drawn a great deal of ire from residents.

In early March, a crane working on the Silver Spring Transit Center shut down the north sidewalk between the NOAA building and the Metro entrance. There is no crosswalk where the sidewalk was closed. When there are so few crosswalks, these closures are particularly disruptive for the hundreds of residents and workers walking to and from retail and Metro.

Pedestrians walking from their apartment buildings to the Metro had to double back to get to a crosswalk, or cross illegally where the sidewalk was shut down. The weekend of March 12-14, surface work at the NOAA garage entrance forced pedestrians to walk in the street for a short stretch. Montgomery County, of course, is no stranger to pedestrian safety problems at construction zones.

The south block, bounded by East-West Highway, Colesville Road, Eastern Avenue, and Blair Mill Road, contains a mix of high-density residential and commercial structures. It is somewhat disorienting to navigate, even for a resident. Ten apartment buildings rise up from the block, many of them surrounded by parking lots. In the center there is an interior-facing shopping center with an enormous surface parking lot. The few pedestrian connections that exist are circuitous, dumping the pedestrian off in the middle of the parking lot. This area was not designed with the pedestrian in mind.

The north block is between the railroad tracks and East-West Highway from Colesville Road to Georgia Avenue. The tracks form a bulwark between all of South Silver Spring and the main portions of the downtown area. Generally, pedestrians have to go an extra half mile around the tracks to get to Ellsworth Drive.

One of the key aspects of walkability is a permeable system. Silver Spring needs a safe, well-lit, well-constructed pedestrian tunnel to Ripley Street or Silver Spring Avenue that cuts through the north block. A tunnel would likely come with a very large price tag. The south block, however, could be broken up with better pedestrian and vehicular connections, much like the planned improvements coming with the redevelopment of Falkland North just across Colesville Road.

Silver Spring is an example of successful infill designed, for the most part, to be walkable. People love living there because of this. If the leftover pock marks could be addressed by the time the new transit center; opens, it would propel Silver Spring towards the top of the list of pedestrian friendly suburban communities.

While a typical objective of creating superblocks is to make a place more pedestrian-friendly, often the superblock's focus on separating vehicles and pedestrians actually can create a place that on the whole lacks cohesion and is not very pedestrian friendly. Current thinking in many planning circles generally supports the idea of now bringing vehicles and pedestrians together as shared users of complete streets, rather than having them exist in isolation.

A leisurely stroll through Crystal City today would introduce one to distinct examples of both.

The "Underground"

The first wave of development in Crystal City included both a legible superblock pattern of development and an interior pedestrian concourse (locally referred to as the Underground) connecting many of the superblocks together.

With the construction of each superblock, multi-lane arterial streets were incrementally built to provide local access to Crystal City's buildings. These streets were often one-way and not exactly pedestrian-friendly, largely due to the limited and meager sidewalk facilities and expansive blank walls at ground level that accompanied the first generation of redevelopment in many places.

The Underground is Crystal City's answer to a less-than-cohesive external pedestrian network. An interior, pedestrian-only network that is climate controlled, traffic free, and sometimes lined by retail, the Underground provides a safe, convenient travel option for pedestrians in Crystal City.

In fact, most buildings in the core of Crystal City provide their tenants with direct access to the Underground via their main building elevators. In some locations, the Underground is complemented by a series of pedestrian skywalks that link together superblocks above grade (although most of these have gradually been taken down in recent years).

Anecdotal evidence suggests the Underground has more than its fair share of users and can be a very active corridor during peak commuting hours. But does this necessarily make for a great urban place? And in an area studied for potential revitalization and redevelopment in the face of pending impacts from BRAC, what challenges or opportunities will Crystal City's superblock form and Underground provide in the quest to make Crystal City a better urban place?

Reshaping Crystal City's neighborhood form

Among other things, the recently-adopted Crystal City Sector Plan generally proposes to guide future redevelopment in Crystal City to break down the superblocks into a more traditional neighborhood development pattern. But how can this be achieved?

One-way streets can be converted to two-way traffic, as is already being done in some Crystal City locations, and new streets can be created wherever possible with redevelopment to provide a more refined urban street grid complete with safe and attractive sidewalks, streetscapes, and pedestrian facilities. Given the community's value placed on the Underground, it is an element embraced by the plan to be maintained, though modifications to its alignment are possible.

In addition to street improvements, key land use and urban design changes in vertical building form can also play a role. For instance, instead of the "towers in the park" typology that characterizes much of Crystal City today, more mid- and high-rise buildings can be placed at the back of the sidewalk and oriented to have their building facades (on at least two sides) help to frame and create the urban spaces that comprise the neighborhood's streets, parks, and plazas.

Even in instances where new streets aren't being created to technically break down the superblock pattern, the introduction of new infill buildings at strategic locations should help to at least create the perception of breaking down the superblock.

In many instances, multi-family residential buildings comprise slender and flexible building forms and are well-suited to smaller or challenged sites. As such, they often can be designed to help define block edges in a more urban manner. Nevertheless, if situated correctly, hotel and office buildings can offer similar opportunities to help break down the perception of superblocks in Crystal City as well.

This type of infill and redevelopment envisioned in the Crystal City Sector Plan has the potential to break down the apparent pattern of superblocks, and provide a more consistent, cohesive, and amenable outdoor pedestrian network at the same time.

Cross-posted at Under One Roof, Arlington County's housing blog.

The Office of Planning's 2006 NoMA Vision Plan and Development Strategy recommends restoring 1st Street NW to its original purpose. This is an area where the Office of Planning, the Committee of 100, and Greater Greater Washington likely agree. If the District sells these lots, it must restore and retain 1st Street.

The city should combine and rearrange its lots into two lots, each flanking a side of the restored 1st Street. The western lot will be contain about 47,650 square feet of land and the eastern lot will contain about 79,100 square feet of land. The eastern lot would be suitable for Wal-Mart, since the chain is looking to build a store as small as 80,000 square feet. A store spanning two floors, much like the Target at DC USA, would obviously double the space to nearly 160,000 square feet.

A Wal-Mart at this location will require the consent of the of District government in selling District land. If we sell the land out of desperation, no questions asked, Wal-Mart will build the cheapest and fastest store it knows best: a big box surrounded by an ocean of parking entirely incompatible with the livable and walkable neighborhoods DC wants. It is a mistake we will regret for decades to come.

Since the land belongs to District residents, we have a right to demand that the Council take care when disposing of it. We should condition the land sale on good urbanist principles, that is, building to the property lines, burying any parking, and providing a mixture of uses (offices, housing, etc.) beyond just a regular store. If structured properly we have the chance to transform a gravel parking lot into a development that, like DC USA, can transform the area around it for the better.

This type of mixed-use development has proven profitable elsewhere in the city. At this location, which is within sight and walking distance of the Capitol, Wal-Mart can undoubtedly earn a handsome profit building a multi-story, mixed-use project. The company will also benefit from displaying a positive case study close to Congress.

With good design, city residents and Wal-Mart can both come out ahead.

To compensate, they propose building a road through adjacent parkland, to create a back entrance to the neighborhood. There are even some houses whose driveways connect directly to Connecticut Avenue. MCDOT is suggesting cutting those off as well in the long run and building more roads inside the neighborhood.

Across the region and the world, communities are trying to make large roads more hospitable to their surrounding communities by increasing the connectivity of roads and adding places for pedestrians to cross. Virginia now requires a certain level of connectivity for new subdivisions. At White Flint, plans call for making a more walkable, bikeable, and transit-friendly boulevard, and even Prince William County is adding a stoplight on VA-234 where a pedestrian (ironically the contractor about to install the light) was killed.

In Montgomery County's DOT and the office of the County Executive, however, no transportation idea less than 50 years old seems welcome. DOT officials constantly talk about "level of service," a measure based on the premise that moving motor vehicles is the only purpose of roads, and use that obsolete concept to grade intersections "F" or "failing." County Executive Ike Leggett keeps trying to kill the White Flint boulevard because it will slightly slow travel times through the area but create a better immediate area.

And in Chevy Chase Valley, they have convinced neighbors that since they need to move Connecticut Avenue cars at high speed, that poses a danger to that neighborhood, and therefore the neighborhood should be partly or fully cut off from Connecticut Avenue.

The better way to avoid the impact of higher speed traffic on Connecticut Avenue is not to make higher speed traffic the objective. Improve access to Medical Center Metro. Build the Purple Line. Build some of Marc Elrich's BRT proposals, too. Put in bus lanes so that transit vehicles can navigate the county more efficiently and become a more appealing alternative.

There will eventually be a Purple Line station nearby, which will create demand for walking along Connecticut Avenue to and from surrounding neighborhoods and businesses. This part of Connecticut Avenue already has far too few places for pedestrians to safely cross. The intersections MCDOT wants to close have no marked crosswalks today (though by law, they areas where crosswalks would be painted are considered crosswalks, like all intersections). The avenue needs to become safer and more friendly to pedestrians, not even more hostile to walking than it already is.

Montgomery County has a lot of choices for addressing BRAC and general growth downcounty. It's too bad Leggett and the officials at the county DOT only have one solution in mind.

My wife loved growing up on her cul-de-sac. Almost all houses had kids around the same age.

They played roller hockey and held bike races on the low-traffic street. They played kickball in front yards, unconcerned that it would be dangerous if the ball rolled into the street. They played flashlight tag in the cul-de-sac and around the houses, with the parents confident it was safe because someone could always see kids from their window.

I grew up on a cul-de-sac, too, but didn't enjoy it nearly so much. I did learn to bike in the cul-de-sac, but mainly played in our front or rear yard. One reason was that there were relatively few houses around our cul-de-sac (4), as our neighborhood had much larger lots. The houses were also set far back from the street, meaning parents couldn't see the cul-de-sac from their kitchen windows.

Kids used to play in the street on grids, too—my dad grew up in the first-wave suburb of Lynbrook, New York, on a rectangular street grid, and would play street hockey. Kids even used to play on the streets of Manhattan. But the cycle of rising traffic and widening of roads made streets into less hospitable places for children, while parents became more protective at the same time.

Cul-de-sacs may work great for smaller children, but as children get older, they prefer the mobility of being able to walk or bike to see their friends, even friends who aren't next door, and to get to stores, bowling alleys, arcades, skate parks, or wherever teens congregate.

The solution is not to continue the domination of cul-de-sacs, but to design other, even better spaces for children. Marcus points to developments that use "shared outdoor space," where houses cluster around large, common yards visible from all houses. Essentially, these are cul-de-sacs but not used for transportation. Many suburban cohousing projects follow this model.

Many new developments are building these spaces, but they're not new. In fact, many of the earliest suburban models had shared green space, including one of our region's planning icons, Greenbelt, Maryland.

Old Greenbelt, the original 1937 "garden city", has two doors to every house: a "service side," facing the roadway, and a "garden side," facing green space covered with gardens, play areas, pedestrian and bike paths, and more.

Essentially, Greenbelt has two "grids": the roadway grid for cars, and the garden grid for people. Residents walk to the stores (centrally located and connected via pedestrian and bike paths) along this garden grid, creating "eyes on the street," just without motor vehicles, and facilitating social interaction.

Matt Johnson wrote, "I regard it as the most tragic of missed opportunities that we were unable to build America's suburbs the way we built Greenbelt. Unlike other suburbs, Greenbelt does not suffer from a lack of interaction (Bowling Alone) or a lack of alternative transportation modes."

Blocks of townhouses (like in central Washington) or closely-spaced single-family houses (like much of Arlington) are great development patterns for almost all ages, but unless designed right, they don't fully accommodate families with small children. Parks are great, but parents need to actively transport kids to the park and watch them while there (or make arrangements with other parents). The cul-de-sac, shared green space, Greenbelt-style "garden side," or other land use patterns allow for kids to play safely while parents take care of other responsibilities at home.

Still, most areas are already built and lack shared green spaces. What can we do? Marcus suggests the woonerf, the street that puts pedestrians first and allows traffic but only at slow speeds and with design cues that clearly tell drivers they are guests rather than owners of this space.

That could return many neighborhood grid streets to their function when my dad was a child, as spaces where children play with breaks for the occasional car. Game on!

Tonight's ReThink Montgomery session, with Joan Almon of Alliance for Childhood, will discuss "how planners can design and build spaces that make it easy for children to be active." The Alliance argues that children need at least 60 minutes a day of undirected play time, but currently get only 12.6 minutes per day. We mustn't neglect children as we work together to improve urban and suburban neighborhoods.

* Some will insist that the plural of cul-de-sac is "culs-de-sac," but I don't like it.