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Show MOTORISTS WILL AVOID ROAD EDGE Much Depends on Width of Road, Curves, Grades and Other Conditions. (Prtpired br the United states Department of Agriculture.) Does the average motor car driver Weep to the right of the road as far as possible or crowd over to the middle? mid-dle? The United States bureau of public roads finds that the answer to the question is affected by the width of the road, curves, grades, slope of road surface, and condition of the surface adjacent to the pavement. pave-ment. This conclusion Is based on observations of the habits of drivers on highways of various kinds, widths, and location. Points were selected for observation and the width of the pavement was marked off with white paint into one-foot sections so that the position of passing vehicles could be observed. Road Position Preferred. In most cases the cars were not passing other vehicles at the InstAit of observation. The Investigation, therefore, indicates the road position preferred by the average driver. Few automobile drivers prefer a position closer to the edge of pavement than 2 feet and on meeting other cars the average driver will sacrifice clearance clear-ance rather than drive closer to the edge that he Instinctively feels to be safe. Truck drivers who, as a class, are sometimes accused of being road hogs are found by the bureau to he not guilty. Most of them were observed to drive a foot closer to the edge of the pavement than drivers of motor cars ana under all circumstances they adhered uiore closely to the side of the road. Eighteen- feet Is found to be the minimum width of roadway which will permit passenger vehicles and trucks driven in the preferential positions to pass in safety and with a reasonable reason-able amount of clearance. This will allow a distance of 2.7 feet between the outer wheel nnH tlio prltro nf tho road for automobiles and 1.8 feet for trucks with 1.9 feet clearance between be-tween vehicles. Shift to Inside. Observations on curves showed that there Is a general . tendency to shift to the Inside of the curve, particularly by the traffic moving on the outside. Improper banking of the road surface, poor shoulders and steep embankments embank-ments on the outside of the curve all tend to make drivers crowd to the Inside. White lines in the center of the road were found to be very effective ef-fective in keeping traffic in Its proper channel. A report on the investigation has been issued by the bureau and It Is felt that the data will be helpful to engineers in deciding on road widths and other problems of road design. |