Traffic is very slow on the entire length of westbound I-66, from Rosslyn to the Toll Road. The backups are so bad that there are reports that ancillary backups have formed on some main local roads that connect with I-66 on-ramps, like Sycamore Street, Washington Boulevard and Glebe Road. Route 110 is also said to be jammed as a result of the I-66 traffic.
Via Twitter, several I-66 commuters have said that the slow traffic has added 30 or more minutes to their westbound commute.