MARENGO – The city of Marengo will host an open house Tuesday at City Hall to answer questions and get public comment on the Interstate 90 and Route 23 interchange project. The multimillion-dollar project that includes widening the bridge and creating an exit at Route 23 is underway, and has been projected to bring an economic windfall to the tune of more than $1 billion to McHenry County. Residents will have a chance to get an update on the status of the project and find out more about the proposed improvements. The open house will be from 4 to 7 p.m.