Build a circle at North Capitol and Irving
DC and federal officials and a team of consultants have created three options for redesigning the cloverleaf interchange at the intersection of North Capitol and Irving Streets. Dubbed the "Memorial in the Park," "Center of Centers," and "Four Corners," each continues the grade separation of east-west and north-south traffic while also trying to create a more hospitable area for people.
North Capitol Cloverleaf overlaid onto Dupont Circle for scale comparison.
The interchange is DC's only traditional freeway cloverleaf interchange, occupying about 19 acres in what is becoming a more urban, more walkable part of the city. The adjacent Armed Forces Retirement Home plans to develop its southeastern corner, adjacent to the cloverleaf, into mixed-use buildings to fund its ongoing operations. Catholic University is growing, and the nearby McMillan Sand Filtration site will become a new neighborhood of its own as well.
The interchange is part of a short freeway piece of North Capitol between more urban segments to the north and south. It encourages high-speed traffic and discourages pedestrians and bicyclists. It generates a large "dead zone" in the surrounding bus network. And it creates inaccessible empty space instead of more valuable parkland that people can actually use.
The study team developed three alternatives. One would reroute the roads to the southeast, creating a park space for a large memorial and giving the roads a "parkway" design. The park would be 7.5 acres, about the same size as Capitol Hill's Lincoln Park. It's also the most expensive of the four, likely costing $40-45 million.
The second option would build a circle with 2.6 acres of green space in the center, a little more than Dupont Circle's 2.3. Like Dupont, one roadway (Irving) would pass underneath, while the other (North Capitol) would use the circle along with turning movements. This would probably cost $37-41 million.
The third would divide the green space into four corner parks, with the larger two about the same size as the Navy Memorial at one acre. A ring road would let vehicles transfer between the two roads. This option is the cheapest, at an estimated $28-31 million. It'd also be possible to also leave out the ring of buildings, creating more empty space instead of stores and residences.
Left to right, top to bottom: The current North Capitol interchange; the "parkway/memorial" option; the "circle" option; the "four corners" option.
According to the study team, replacing the interchange with a simple at-grade intersection would require each roadway to have ten lanes, and even then cars would take longer to move through the intersection, not to mention the very long pedestrian crossing times.
DC should choose the circle design. It builds on the existing L'Enfant public space vocabulary of Washington. The well-designed circles mix public parks and vehicular movements in a generally pleasing balance. However, the circle actually be circular. An oval shape might help the cars move through the area a bit more quickly, but at the cost of some parkland. Also, encouraging cars to slow down through the area would improve this public space. A circle works fine for DC's existing circles, and would preserve the continuity across the city.
I'm also curious if the study team evaluated having both roadways pass underneath the circle, meeting at a traffic light underground while turning cars still use the circle. I've always wondered if that would improve Dupont Circle. It would slow traffic passing through somewhat, but since cars wouldn't have to wait for left turning movements, would delay drivers far less than a regular at-grade intersection.
The "memorial" design looks too much like the Kennedy Center's "ramp spaghetti" and other contemporaneous designs that aren't really pedestrian-friendly. That design creates a park that would serve the AFRH development well, but cuts the park off from the other sides. One day, the VA Medical Center or the houses to the southeast could become more walkable in design, and the interchange should not hinder that possibility. Likewise, residents of the future McMillan site development should be able to walk to this plaza without passing over and under ramps clearly designed for vehicles above all.
The "four corners" is okay, but the park is either too small or too large. If built, the ring of buildings cuts off the parks from the roadway, decreasing "eyes on the street" and making the park into more of a courtyard for the buildings. Without the buildings, it's just a larger version of the circle with an uncrossable road cutting it in two. There are no crosswalks on North Capitol in the middle, meaning people will have to walk all the way to one end to cross, or dash dangerously across midblock.
The study also briefly considers Irving and North Capitol outside the cloverleaf. It recommends redesigning North Capitol into a greenway with a median and hiker-biker sidepath north of the cloverleaf, and into an urban boulevard with wide sidewalks and off-peak parking south of the cloverleaf. Other recommendations include reducing travel lanes on Irving to add a bicycle lane, and removing the "slip lanes" to make the intersection of Michigan Avenue and Irving Street a more pedestrian-friendly, 90-degree standard intersection. To help drivers, it recommends widening Michigan Avenue slightly at 1st Street, NW to lengthen the turn lanes and add protected left turn phases to the traffic lights.
All of the designs show potential locations for stops on a future Irving Street transit line. For now, that could mean a rerouted H bus or a future Circulator, but in the future this corridor should get light rail or a streetcar running from Woodley Park to Brookland. Metro is also considering giving it the "Priority Bus Corridor" treatment like 16th Street or Georgia Avenue; the 80 bus on North Capitol is already on the priority corridor list, though at the very bottom.
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