Workers at the site of the bridge over Sullivan Run along Cunningham Street have begun construction to replace the existing structure with a box culvert. The $2.2 million project began April 25 and is expected to continue until mid-October. Motorists in the city also will have to deal with a Main Street paving project from the General Butler Bridge to Penn Street that is scheduled to run from Monday through July 29. That work is expected to take place between Monday evenings at 6:30 p.m. and Friday mornings at 7:30 a.m.