ARTERIAL INTERCHANGE Four exit ramp split level SPUI

ARTERIAL INTERCHANGE Four exit ramp, split level (SPUI) With offset intersections SRF Consulting Group – May 2006

VISSIM SCREEN SHOTS • Volumes used in simulation – year 2030 pm peak hour, for Mn Hwy 55 at Vicksburg Lane in Plymouth – WB Mainline (underpass) 2910 • Left turns – 120 • Right turns – 415 • Mainline through – 2375 – EB Mainline (underpass) 1795 • Left turns – 245 • Right turns – 225 • Mainline through – 1325 – NB Cross street (over crossing) 1510 • Left turns – 480 • Right turns – 120 • Throughs – 910 – NB Cross street (over crossing) 1020 • Left turns – 280 • Right turns – 320 • Throughs – 420 • Represents junction of principle arterial (55, 000 ADT) with minor arterial (25, 000)

Two signal controlled intersections Signals on each level to handle left turns from ramps. Right turns have extended acceleration lanes to enter mainline and Yield control to enter cross street. Lower volume left turns from each roadway have complex alignment to create single intersection of opposing lefts while retaining a rectangular bridge shape.

Underpass Cross street follows a ridge. Mainline is lowered under intersection with 17 feet of vertical clearance.

FOUR EXIT RAMP SPLIT LEVEL SINGLE POINT (offset intersections) INTERSECTION DETAILS Offset single intersection allows for exit ramp lefts to be made concurrently. Alternative design has separate “conventional exit ramp intersections, but uses one signal controller with “split” phasing for the exit ramp greens, less capacity, but narrower bridge.