The second phase of the Highland Park roundabout (read about it here) started earlier this week. From the Department of Public Works:
Beginning Tuesday, September 16, crews will begin Phase Two of the Highland Park Roundabout project, after successfully completing Phase One of the project (along Rowen Street ). During Phase Two, a concrete sidewalk will be constructed along Matthews Street . Crews will also place concrete median islands and a new City standard curb.

During this construction, Matthews Street will be closed to vehicular traffic. All work associated with this street closure will be completed by Friday, September 26, 2008.