Figure 8. Site geometry. Two figures are shown. On the left, an ellipse divided into six parts by a vertical line down the center and two horizontal lines across the ellipse at one-third and two-thirds the length. The upper horizontal line is labeled the center of lane of travel. The leftmost end of this line shows the vehicle minimum-separation distance marker. The intersection of the vertical line and the upper horizontal line is labeled as a passing point. A car is also depicted on this horizontal line. A length of 15 meters (50 feet) is given as the distance between the horizontal lines. The radius of the ellipse is 30 meters (100 feet). A microphone is located at the intersection of the vertical line and the lower horizontal line. An observers' station is to the left of the ellipse between the horizontal lines.

The figure on the right is a roadway and uneven off-road surface to the right. A microphone mounted on a support device is on the off-road surface at a height of 1.5 meters (5 feet) above the road.

return