Baltimore County News
Keith Duerling, P.E.
Structures Division, Bureau of Engineering
Department of Public Works
Baltimore County has 675 bridges of all sizes – from major spans that carry thousands of cars each day, to culverts which are merely drain pipes allowing small streams to flow under roads. But whether the structures are big or small, they all deserve (and get!) the same careful, regular inspection which ensures the safety of the traveling public.
Baltimore County classifies its bridges by length: structures over 20 feet and structures under 20 feet. Bridges are inspected every two years by a qualified, engineering company. These consultants are selected by the Maryland State Highway Administration for Baltimore County and the cost of the inspections is borne by the Federal government. Bridges that are less than 20 feet are handled in much the same way, except that the County selects the bridge inspectors and the State of Maryland pays for 80% of the inspection cost.
During the inspection process, engineers assess the condition of (1) bridge decks (i.e. the travel surface), (2) the superstructure, (3) the substructure, (4) the condition of the structure exposed to rivers, streams and runs, and (5) the condition of culverts. Inspection is a hands-on exercise and crews visually take the spans apart looking for signs of aging, deterioration, cracks, structural movement or any telltale sign of wear and tear. On occasion, steel structures may require ultrasonic testing, but most of the examinations depend on engineering knowledge and experience. Potential problems are described and assessed in detailed written reports and any bridge with negative indicators is put on a repair or replacement schedule.
Bridge safety is of paramount importance in the County because the Department of Public Works and its engineers recognize that there are no second chances when it comes to bridge safety. Every traffic-bearing structure in Baltimore County is continuously monitored and rigorously inspected every two years. In short, structural problems are addressed well before they can impinge upon travel safety.