Everything You Ever Wanted to Know About 42nd St. Circles

Traffic Circle Sign

The crunch of car tires on plastic, debris in the roadway, and the flimsy white plastic barriers that have come to characterize the mini-circles on 42nd Street may soon be a thing of the past. The District Department of Transportation is currently pursuing permits from the Department of Consumer and Regulatory Affairs to install permanent roundabouts at the intersections of 42nd and Warren streets.

As anyone who reads the Tenleytown listserv knows, the neighborhood roundabouts have not been without controversy. Every few months complaints surface, coinciding often with the circles’ heightened states of disrepair. Questions arise about the circles’ genesis, efficacy, and the decision making process surrounding their installation. Most criticisms acknowledge the need for traffic calming along this section of 42nd Street, but take issue with how the circles have been implemented.

After recent community complaints resulted in an NBC4 story and following discussions with fellow residents, Tenleytown, D.C. decided to look into the history of – and future plans for – the circles, which it turns out have been more than four years in the making. 

Genesis of Neighborhood Traffic Circles

In 2010, the District Department of Transportation initiated the Rock Creek West II Livability Study to “take a big picture look at the street network and identify concrete actions to increase transportation and safety options in the study area,” which included AU Park, Chevy Chase, Forest Hills, Friendship Heights, and Tenleytown. Through a series of public meetings, meetings with stakeholders, traffic data assessments, and an online survey, the study identified dangerous “hot spots.” Not surprisingly, 42nd Street between Van Ness Street and River Road was classified as a hot spot.

Frequently used by motorists to bypass traffic on Wisconsin and Nebraska avenues, study participants and survey respondents noted persistent problems with motorists speeding, running stop lights and stop signs, and failing to yield along 42nd Street. During the two-year period between 2007 and 2009, DDOT recorded 20 vehicle collisions and one pedestrian collision along this roadway. The presence of Janney Elementary School, the St. Columba’s nursery school, and a retirement community on the street raised additional concerns for vulnerable pedestrian populations.

For the intersections of Warren and 42nd streets, the final study report, which was issued in February 2011, noted residents’ concerns about motorists speeding and taking turns onto Warren Street at excessive speeds, as well as a lack of existing measures to control traffic. Warren Street splits into a “V” at 43rd Street, intersecting with 42nd Street in two places. The report recommended that DDOT install neighborhood traffic circles at the intersections, citing that “neighborhood traffic circles, particularly when placed in progression are one of the most effective traffic calming tools to reduce speeds.” The recommendation for 42nd Street was consistent with the report’s system-wide recommendations for collector streets.

Tenleytown’s Advisory Neighborhood Commission, subsequent to the release of the final report, passed unanimously a resolution calling upon DDOT to “make implementation of recommendations for the 42nd Street corridors a top priority, including installation of curb extensions and neighborhood traffic circles.” The commission also recommended that DDOT ask American University, which had announced plans to move its law school to the nearby Tenley Circle campus, to help foot the bill for the improvements.

The stipulation that AU fund traffic calming measures was later included in an agreement between the university and the Tenley Campus Neighbors Association. An organization comprised of property owners residing within 200 feet of the Tenley Campus, TCNA opposed the relocation and expansion of the Washington College of Law. In exchange for TCNA withdrawing its opposition to AU’s plans and request for zoning variance, the university committed to “pay all costs, up to a maximum of $400,000, necessary to implement each of the traffic calming measures identified [for 42nd Street] in the Rock Creek West II Livability Study,” including the installation of circles at 42nd and Warren streets.

The Zoning Commission, at the urging of the ANC and TCNA, adopted the TCNA-AU agreement language regarding the university’s obligations to implement traffic calming measures as part of Zoning Order 11-07B, which was approved on April 9, 2012. Appended to the order was a memo from Sam Zimbabwe, Associate Director of Policy, Planning, and Sustainability at DDOT, conditioning the department’s support for zoning relief on the requirement that the university “construct traffic circles at the diagonal entry points of Warren St.”

Test Driving Temporary Circles – DDOT Assessment

A car navigates one of the traffic circles shortly after their installation.

A car navigates one of the traffic circles shortly after their installation.

Nearly a year and a half later, DDOT issued a notice on August 27, 2013 that it planned to install temporary traffic circles on 42nd Street. The temporary circles, which were subsequently installed in October 2013, were intended to allow the department to assess their impact and feasibility over a six-month period without making permanent alterations to the roadway. Based upon the results of the test period, DDOT would then install permanent circles.

In a May 2014 report assessing the temporary circles, DDOT noted initial confusion over traffic patterns around the circles, but indicated drivers adjusted within a month of their installation. Anecdotal evidence from neighbors, however, would seem to contradict this assessment as residents continued to recount stories of drivers taking the wrong direction through the circles and being uncertain when to yield. A lack of proper signage has been cited as a contributing factor to driver confusion. At the November 2013 ANC meeting, 42nd Street resident Jerry Weiss told commissioners that “it feels very chaotic right now.” Other residents, while still supportive of efforts to reduce speeds along 42nd Street, continue to offer similar observations.

DDOT acknowledged in its report that traffic moving southward on 42nd Street is slowed more by the circles than that headed north. In response, the department bumped out the curb just south of the southern-most circle by installing plastic pylons, which force drivers traveling north to slow down as they navigate the new bend in the road. DDOT intends to adjust the placement of the permanent circles, moving them slightly east to balance their effect on drivers traveling in both directions.

Overall the report noted mixed feedback from residents and drivers. Comments from commuters were “generally negative,” while residents of the block approved of the circles’ impact on decreasing vehicle speeds and commercial truck traffic. However, the report indicated that those whose properties were directly impacted by the circles, for example by their placement or elimination of a curbside parking space, expressed negative opinions about the circles. Similar mixed feedback was offered at ANC meetings in September, October, and November 2013 and in June 2014, though on balance residents’ comments in these venues have indicated support for traffic calming on 42nd Street and, in the absence of alternatives, modifications to the circles to make them safer and more effective.

A major complaint not referenced in DDOT’s report is the durability of the current circles. Cars frequently drive over the plastic strips that mark the circles, leading to unsightly, broken pieces of plastic that migrate into the roadway creating hazards for motorists. DDOT has periodically replaced broken pieces and refurbished the circles during the temporary phase, which has stretched well beyond the anticipated six-month testing period. Fortunately, once the permanent circles are installed, debris from broken circles should no longer be an issue.

What’s Around the Corner

Conceptual rendering of permanent circles by ANC 3E. The tree in the circle will likely be replaced by shorter plantings.

Conceptual rendering of permanent circles from ANC 3E. The tree in the circle will likely be replaced by shorter plantings, such as the low shrubs that are also depicted.

While a timeline for the construction of permanent roundabouts is unclear, what is certain is that the neighborhood circles are here to stay. DDOT has ruled out other measures to reduce vehicle speeds, such as additional stop signs or speed humps, which are typically not used on collector streets. The ANC and TCNA have urged DDOT to move forward quickly with installation of permanent circles, in part to address the poor aesthetics and durability of the temporary ones and, more importantly, to improve their efficacy.

DDOT’s proposal for the permanent structures addresses most, if not all, of the criticisms levied at the current circles, many of which were captured in the department’s own assessment report. The new traffic circles will be made of durable materials and will include a mountable apron to allow emergency vehicles to traverse the circles with greater ease, and landscaping to improve their visual appeal. While initial renderings indicated that small trees might be planted in the middle of the circles, DDOT will likely substitute small shrubbery, flowers, or grasses for the proposed trees due to safety considerations.

Signage will be added to alert drivers to the new traffic pattern, warn them to yield to traffic in the circle, and watch for pedestrians in the crosswalks. DDOT is also proposing to add directional markers on the roadway.

To address current pedestrian safety concerns, the crosswalk at the south circle will be moved, as it currently intersects the circle. Additionally, the temporary curb extension at the south circle would be made permanent through the addition of a sidewalk and small grassy area between the sidewalk and roadway – contributing to both pedestrian safety and helping slow northbound traffic. As referenced earlier, the circles will be moved slightly eastward also to slow traffic headed north.

While the temporary circles at the intersections of Warren and 42nd Streets have been problematic, to say the least, and are probably not the route DDOT should take in the future, they were the product of a lengthy deliberative, consultative process and ultimately allowed DDOT to make important modifications to its final plans for the permanent circles.

Residents may not like the circles in their current iteration – we certainly don’t. However, the permanent version should take care of the negative aspects of the circles, while strengthening their impact on reducing speeds on 42nd Street, which is something certainly most residents can get behind.

According to the Rock Creek West II Livability Study, DDOT is expected to continue monitoring the efficacy of the circles, and present another assessment report two years after their installation.



Editors Note: This post was updated to correct an error regarding the funding provision that was included in the AU-TCNA agreement. An earlier version attributed the provision to an ANC commissioner; however, it was the result of the input of several individuals and a series of negotiations between AU and the TCNA.


  • Many people confuse other and older styles of circular intersections with modern roundabouts. East coast rotaries, large multi-lane traffic circles (Arc D’Triomphe, Dupont Circle), and small neighborhood traffic circles are not modern roundabouts. If you want to see the difference between a traffic circle, a rotary (UK roundabout) and a modern roundabout (UK continental roundabout), go to http://tinyurl.com/kstate-RAB to see pictures. And here’s another site that shows the difference between an older rotary and a modern roundabout: http://tinyurl.com/bzf7qmg

    Mini-roundabouts are less common in the US, but frequently used in the UK. They are all truck apron. Some US examples:
    White Center, WA: http://tinyurl.com/white-center-mini
    Dimondale, MI: http://tinyurl.com/dimondale-mi-mini
    Missoula, MT: Toole and Scott: http://tinyurl.com/mnwnrml
    San Buenaventura, CA: http://tinyurl.com/sbv-ca-mini
    Anacortes, WA: http://tinyurl.com/AnacortesMini

  • The traffic circles on 42nd Street are poorly placed, making it quite easy to drive in the Van Ness to Yuma direction, but excruciatingly convoluted to drive in the Yuma to Van Ness direction. I now avoid 42nd Street and use 43rd Street instead. It would make much more sense to install traffic humps like the ones on Upton between Reno and Wisconsin or like the one on Tilden down by Pierce Mill.

    • The permanent traffic circles will not be at the same location as the temporary circles. The circles are a much better form of traffic calming. Humps are dangerous for cars and even more so for bicycles.

      I think most people thinking about traffic calming don’t think about how they affect any traffic except cars.

      Others have suggested stop signs. But there are three intersections of Warren and 42d St. Would you really prefer 3 new stop signs instead of the mini-circles?