A series of accidents this morning snarled rush-hour traffic on Interstate 66 in Virginia and Interstate 270 in Maryland, two of the area's major commuter highways.

Traffic was backed up about two miles on eastbound I-66 before the Haymarket exit at the height of the rush hour.

An accident involving an overturned 18-wheel tractor trailer, which occurred shortly before 2 a.m., was moved to the median, but was still on the side of the road as rush hour traffic built up on the Virginia commuter roadway. That caused traffic to slow as it passed, resulting in delays for miles before the Manassas Route 234 exit. Delays were also reported going westbound on I-66 from rubber-necking motorists.

A second accident occurred on I-66 at about 6 a.m., causing the two left lanes to be blocked before exit 50. Traffic was also slow on Routes 29, 25, and 234 getting onto I-66.

Two separate accidents on I-270 in Maryland also caused traffic back-ups this morning, but the accidents were cleared by 8:30 a.m. The accidents occurred at I-370 and after the truck scales on the Maryland highway.

Another accident on the westbound Dulles Toll Road before Wiehle Avenue in suburban Virginia diverted traffic off the access lanes during the rush hour.