1360.02(2)(d) Partial Cloverleaf
A partial cloverleaf (PARCLO) has loop ramps in one, two, or three quadrants that are used to eliminate the
major left-turn conflicts. These loops may also serve right turns for interchanges where ramp cannot be built in
one or two quadrants. Outer ramps are provided for the remaining turns. Design the grades to provide sight
distance between vehicles approaching these ramps.
1360.02(2)(e) Diamond
A diamond interchange has four ramps that are essentially parallel to the major arterial. Each ramp provides for
one right-turn and one left-turn movement. Because left turns are made at grade across conflicting traffic on the
crossroad, intersection sight distance is a primary consideration.
The diamond design is the most generally applicable and serviceable interchange configuration and usually has a
smaller footprint than any other type. Consider this design first unless another design is clearly dictated by
traffic, topography, or special conditions.
1360.02(2)(f) Single Point Urban
A single point urban interchange (SPUI) is a modified diamond with all of its ramp terminals on the crossroad
combined into one signalized at-grade intersection. This single intersection accommodates all interchange and
through movements.
A single point urban interchange can improve the traffic operation on the crossroad with less right of way than a
typical diamond interchange, but a larger structure.
Chapter 1360
Interchanges
WSDOT Design Manual M 22-01.20
Page 1360-4
September 2021
Exhibit 1360-1 Basic Interchange Patterns
Cloverleaf With C-D Roads
Diamond
Partial Cloverleaf
Directional
Semidirectional
Single Point Urban
Interchange (SPUI)
Chia sẻ với bạn bè của bạn: |