Abstract:
SIMPLE PASSINGS, ONE VEHICLE PASSING ONE OTHER VEHICLE, WERE CLASSIFIED ACCORDING TO THE MANNER IN WHICH THE PASSING VEHICLE WAS AFFECTED BY OPPOSING TRAFFIC, AS FOLLOWS: (1) DELAYED START, (2) HURRIED RETURN, (3) DELAYED START AND HURRIED RETURN, AND (4) FREE MOVING PASSINGS WITH NO OPPOSING TRAFFIC. IT WAS FOUND THAT THE AVERAGE DISTANCES USED THE LEFT LANE BY THE PASSING VEHICLE FOR THESE FOUR TYPES WERE (A), 601 FEET; (B), 601 FEET; (C), 521 FEET, AND (D), 703 FEET. MOST PASSING VEHICLES DESIRED TO TRAVEL ABOUT 10 MPH FASTER THAN THE VEHICLES THEY PASSED BUT SELDOM MADE A PASSING BEFORE SLOWING TO A SPEED WITHIN 5 MPH OF THAT OF THE CAR AHEAD. PASSING DISTANCE WAS FOUND TO INCREASE NOT ONLY WITH THE SPEED OF THE PASSED VEHICLE, BUT WITH THE SPEED OF THE PASSING VEHICLE AS WELL. THE TIME SPENT IN THE LEFT LANE IS AN IMPORTANT FACTOR IN ANY DETERMINATION OF HIGHWAY CAPACITY. SUMMARIZATION OF THE WORK DONE THUS FAR CONSISTS IN CONSTRUCTING A SERIES OF VALUES OF TOTAL SPACE REQUIRED FOR PASSING MANEUVERS AT VARIOUS VEHICLE SPEEDS. SINCE THE DRIVER DOES NOT NEED TO SEE THIS ENTIRE SPACE ALONG THE ROADWAY BEFORE STARTING TO PASS, THESE DO NOT NECESSARILY REPRESENT PASSING SIGHT DISTANCE REQUIREMENTS. IT IS EMPHASIZED THAT THE PASSING MANEUVER IS AN EXTREMELY FLEXIBLE ACTION AND THE DRIVER CAN BE EXPECTED, WITHIN CERTAIN LIMITS, TO CONTROL HIS PASSING IN ACCORDANCE WITH THE SIGHT DISTANCE RESTRICTIONS PRESENT. /AUTHOR/
Supplemental Notes:
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