The roundabout on the north end of the Charles Street bridge over the Beltway will be taken out as part of the current, $44 million bridge replacement project that is causing a world of disruption, State Highway Administration officials say.

The roundabout, which lies at the intersection of Charles and Bellona Avenue, will be replaced by a traffic signal, said District 4 engineer Dave Malkowski.

Most of the roundabouts the SHA has installed have been quite successful, but the one at Charles and Bellona has been more troubled than others, Malkowski acknowledged. Largely because of  the relatively  small space it occupies, traffic doesn't flow as smoothly as through other circles and vehicles  tend to back up.

According to the bridge replacement project manager, the roundabout will be eliminated toward the end of the job -- probably  llate 2011 or early 2012.

During a  tour of the site Wednesday, Malkowski also pointed out that the new bridge will have full sidewalks on both sides as well as two 5-foot-wide bike lanes. The inclusion of such amenities reflects a growing realization at the SHA that infrastructure needs  to accommodate pedestrians and bicycles as well as motor vehicles.