Talk:233.2 At-Grade Intersections with Stop and Yield Control

The minimum sight distance for at-grade intersections, entrances, and median openings, measured along the centerline of the main road, is equal to the Entering Sight Distance based on the operating speed of the main road. This distance is based on a 3.5 ft. (1070 mm) height of eye and 3.5 ft. (1070 mm) height of object. The minimum sight distance at all grade intersections measured along the minor road, is the stopping sight distance based on the operating speed of the minor road.

IS THE HEIGHT OF OBJECT REALLY 3.5? The Stopping sight distance height of object is 2, under Driveway and entrances, the entering sight distance is 2.

If this is the case for the 3.5' height of object, the vertical curves will have to be manually calculated instead of using geopak. Also, if this is the case, the below chart will have to clearly define that the distances are calculated differently from one another.

Speed (mph) Minimum Stopping Sight Dist. (ft.) Entering Sight Dist. Passenger Vehicle (ft.) Entering Sight Dist. Combination Truck (ft.) Length Of Leg (“d”) (ft.) 30 200 335 505 140 35 250 390 590 165 40 305 445 675 195 45 360 500 760 220 50 425 555 870 245 55 495 610 930 285 60 570 665 1010 325 65 645 720 1090 365 70 730 775 1180 405