Page:Highway Needs of the National Defense.pdf/38

24 TUNNELS IN RURAL AREAS

Seven tunnels are in Pennsylvania. They range from 3,512 to 6,792 feet in length, and all provide 23 feet horizontal and 14.3 feet vertical clearance. All are approached by four-lane divided highways, and carried an hourly traffic of 800 to 1,000 vehicles in 1948.



There are four tunnels in Oregon. These vary in length from less than 400 feet to 827 feet, and in width from 16% to 26 feet. Their 1948 hourly traffic was between 260 and 320 vehicles. Vertical clearance on all is 16 feet or more.