historic context of maryland highway bridges built between 1948 ...

SECTIONTHREEHistoric Contextcontrol commercial encroachment and limit access to the roadway (State Roads Commission1940:xvii-xix).The twenty-year plan was the culmination of several years of research and analysis intoMaryland‘s roads. Begun in August 1936, planners thoroughly investigated the scope andphysical condition of the road system and highway structures, including bridges. The plannerswere looking to understand how Maryland‘s highways did not meet the present needs ofmotorists and to project how they might not meet future needs. The planners studied thecharacter and volume of traffic flow and predicted traffic growth in the future in order to developthe construction program based on objective criteria. The plan recommended improvements andtheir locations, and the manner in which highway funds could best be utilized (State RoadsCommission 1940:1-2).The planning survey counted 703 bridges that were twenty feet or more in length on the ruralstate highway system. Of those bridges, 24 were judged as being in poor condition and 120 asfair. Approximately 60 percent of the bridges averaged 110 feet in length and 20 to 26 feet inwidth. Another 11 percent of bridges were even narrower and longer. Engineering studies hadthus far shown that 20 feet of paved surface was the minimum for safe passing on lightlytraveled two-lane roads and that an additional 10 feet was best to minimize the possibility ofcollision with bridge railings. Only 29 percent of bridges in existence in the late 1930s hadwidths of 27 feet or more. Since a width of 27 feet was inadequate for bridges on three and fourlaneroads, the number of bridges deemed inadequate was even higher. Consequently, about 20percent of the state‘s bridges were posted with load and speed restrictions. The study concluded,―[t]hese narrow and defective structures are extremely hazardous to traffic, and their replacementforms a logical part of the modernization program‖ (State Roads Commission 1940:14-15).A SRC publication from the same period, Modernizing Maryland Highways, emphasized thecommission‘s desire to address the ―deficiencies‖ and ―inadequacies‖ of the state highwaysystem. This pamphlet exhaustively listed highway problems including 600 sharp curves, 1,500steep grades, 16,000 places where obstructions limited sight distance, and more than 400inadequate bridges, among numerous other problems. The SRC called for funding on over $216million through 1960 with $55 million ―urgently needed within the next five years‘ to pay thecosts of modernization. The SRC suggested that a boost in registration fees for commercialtrucks be increased, changes made to refund claims on motor fuel taxes, and consolidation ofhighway administration to pay for the program (Modernizing Maryland Highways c.1940).With the threat of involvement in wars in Europe and Asia imminent, pundits, politicians andsome road builders discussed the idea that an interstate system could strengthen internal nationalsecurity. The American Road Builders Association (ARBA) suggested in 1940 that ―[a] networkof limited access highways is highly desirable in any plan of national defense at a time when anew world conflict is threatened‖ (Kuennen 2001a:23).The limited-access design of the Pennsylvania Turnpike, which opened in 1940, became a modelfor future interstates. Built as a four-lane ―superhighway‖ through the Allegheny Mountains, thePennsylvania Turnpike was the first road in the United States that had no cross streets, norailroad crossings, and no traffic lights over its entire length. When the war ended, trafficmushroomed and plans were made to extend the turnpike east to Philadelphia and west to Ohio.Traffic volume by 1950 reached 4.4 million vehicles, nearly 3 1/2 times what the planners had\15-SEP-11\\ 4-5