A one-car accident in the southbound lanes of Interstate 83 near Cold Spring Lane has caused a two-mile backup, according to police.

Authorities say a car spun out of control and hit a rail about 6:30 a.m. The accident has left the right two lanes of the highway open.

Separately, a motivational speaking event at the First Mariner Arena this morning was expected to increase downtown traffic volume and jam parking garages in the central business district for most of the day.

According to the Baltimore Department of Transportation, thousands of people are expected to attend the "Get Motivated Business Seminar" at the arena, increasing the normal volume of traffic downtown. Officials predicted traffic tie-ups during the morning and evening peak commuting hours as a result of the event set to run from 8 a.m. to 4:45 p.m. But according to transportation officials, traffic was moving at a normal pace downtown as of 8:20 a.m.

The transportation department urged attendees to take light rail to the event, noting that free parking is available at several stations, including North Linthicum, Cromwell and Patapsco Avenue.

Baltimore Sun reporter Michael Dresser contributed to this article.