What DDOT and neighbors can learn from Linnean Avenue’s “slurry seal” project

Workers applied a thin layer of asphalt on Linnean Avenue in a process called “slurry sealing.” (photos by the author)

by Paul Walters

The DC Department of Transportation (DDOT) recently completed a “slurry seal application” project on Linnean Avenue NW. According to a flyer distributed to neighbors on the project route, “the project involves the application of a thin layer of asphalt emulsion (liquid asphalt) over the existing roadway surface.”

DDOT’s website further explains that slurry sealing is one of the District’s “resurfacing strategies”, and “the treatment seals cracks on existing roads and protects the roadway surface from occurrences that cause normal wear and tear, thus slowing down the deterioration rate of the pavement.” (See DDOT’s explanation of this and other strategies here.)

The roadway after sealing.

The project generated a bit of concern among residents along Linnean Avenue when signs went up declaring no-parking restrictions on Linnean from June 27 to July 8. The signage did not explain the purpose of the restrictions. Residents did not receive the flyers describing the slurry seal project for another few days.

More information, distributed more widely, would have aided DDOT. Even with the signage and direction given to motorists and others by the on-site project staff, the applied sealcoat was occasionally damaged in spots when drivers were unable to follow instructions to stay off the materials until several hours had passed, giving time for proper drying.

Council member Mary Cheh’s office (in particular Director of Constituent Services Dee Smith) was instrumental in working with DDOT Director Leif Dormsjo for better information on this and future projects which could have an unclear effect on residents.

Residents interested in the environmental effect of applying the material were told by Director Dormsjo that “our materials confirm to federal [sic] environmental standards and we routinely test samples in the field to ensure compliance.” Older, coal tar-based paving and sealcoat products were banned from use in the District in 2009.