OAKLEY -- An East Contra Costa bicyclist in his early 50s was killed Sunday afternoon when struck by a truck pulling a trailer on a busy thoroughfare, police said.

The bicyclist, who has not been identified pending notification of family, was traveling east on Main Street between Teakwood Drive and Empire Avenue around 1 p.m., Sgt. Jeff Solomon said.

Police continue to investigate the circumstances behind the collision, but it appears the rider was in the bicycle lane before veering into the traffic lane and into the path of the truck, Solomon said.

The cyclist was pronounced dead at the scene by first responders.

The driver of the truck did not appear to be intoxicated, Solomon said.

Westbound Main Street has reopened, and eastbound Main is expected to reopen by 9 p.m.

Contact Paul Burgarino at 925-779-7164. Follow him at Twitter.com/paulburgarino.