UPDATE: VDOT reports the accident has been cleared.

The major northbound delays have lasted for hours today on northbound Interstate 81 in the Buchanan area. The main problem is an accident involving several tractor trailers that has blocked the northbound side near milemarker 168. The northbound side has been closed entirely, traffic is backed up for miles, and it is now making a slow detour on US 11 through Buchanan.