Where, on rural sections of the system expected to carry an average daily traffic of 2,000 but less than 3,000 vehicles, grades are separated and access facilities are to be provided, the interregional highway shall be widened to provide two lanes for traffic moving in each direction, the lanes for traffic moving in opposite directions shall be separated by a median strip at least 4 and preferably 15 feet wide, and ramps or connections between the intersecting roads shall be provided in the same manner as at grade-separated intersections with access facilities, on sections of the system designed with 4 or more traffic lanes.
Where, on rural sections of the system expected to carry an average daily traffic of less than 2,000 vehicles, grades are separated and access facilities are to be provided, the ramps or connections between the intersecting roads shall be constructed in such manner as to permit exit from or entrance to the interregional highway by right-turning movements only.
Access at crossings at grade.—Where, on rural sections of the system designed with four or more through-traffic lanes, access is to be provided from an intersecting highway and it is not deemed financially feasible immediately to separate the grades of the intersection, separate channels shall be provided for all right-turning movements, the median strip of the interregional highway shall be not less than 40 feet wide at the intersection, and adequate space shall be provided for all crossing and left-turning vehicles to stop clear of the through-traffic lanes and proceed across the interregional highway or merge with and emerge from the through traffic on the interregional highway in safety. (See plate VII.)
Where, on rural sections of the system expected to carry an average daily traffic of 2,000 but less than 3,000 vehicles, access is to be provided from an intersecting highway and it is not deemed financially feasible immediately to separate the grades of the intersection, the interregional highway shall be widened to provide two lanes for traffic moving in each direction, the lanes for traffic moving in opposite directions shall be separated by a median strip at least 15 feet wide, and the intersection shall be designed in the same manner as at grade crossings on sections of the system designed with four or more traffic lanes.
Where, on rural sections of the system expected to carry an average daily traffic of less than 2,000 vehicles, access is to be provided from an intersecting highway, and it is not deemed financially feasible to separate the grades of the intersection, the intersection shall be designed to provide adequate space for right-turning vehicles safely to merge with and emerge from the through traffic on the interregional highway. Such space shall also be sufficient to permit vehicles turning left from the interregional highway to halt if necessary at the center of the intersection before completing the turning maneuver and to permit through traffic to pass such halted vehicles in safety.
Alinement of ramps or connections.—Ramps at grade-separated intersections on rural sections of the interregional system shall preferably be designed as one-way roads separated for the whole length of ramp. Where two-way ramps are used, entrances and exits at the interregional highway and, if deemed feasible, at the
