Interchange of the Week
Monday, 15 December 2003
Meadowbrook & Northern State Parkways, Westbury
A full-size image (1.07 MB) showing greater coverage is also available.

Orientation: The Northern State Parkway (reference route 908G) curves across the top of the photo. The Meadowbrook State Parkway (reference route 908E) branches from it, toward the bottom. Glen Cove Road, a Nassau County highway, is the surface road running from bottom to top. NY 25 (Jericho Turnpike) runs from left to top, while NY 25B (Hillside Avenue) enters at top left and ends at NY 25.

Exit numbers: From the eastbound Northern State Parkway, Exit 31 is for Glen Cove Road (to NY 25) and Exit 31A is for the Meadowbrook State Parkway. From the westbound Northern State Parkway, Exit 31A is for the Meadowbrook State Parkway, with a connection to NY 25 via Glen Cove Road. The westbound Exit 31, for Glen Cove Road (shown on the full-size image), is off the upper left corner. The interchange is not a numbered exit from the Meadowbrook State Parkway.

The interchange: The northern terminus of the Meadowbrook State Parkway is a semi-directional T junction with the Northern State Parkway, located between Westbury and Mineola. All ramps intersecting the Northern State Parkway do so from the right-hand side. This interchange abuts the intersection of Glen Cove Road and NY 25, and overlaps a partial interchange serving these surface highways. From the eastbound Northern State Parkway, Exit 31 splits off immediately ahead of the Exit 31A ramp to the Meadowbrook State Parkway. Exit 31 provides access to both directions of Glen Cove Road, as well as to NY 25 and NY 25B. At this point there is also a corresponding entrance ramp making full connections.

From the two-lane ramp connecting the westbound Northern Parkway to the Meadowbrook Parkway, another ramp splits off to meet Glen Cove Road northbound, leading to NY 25 and NY 25B. (The Exit 31 ramp farther west connects to both directions of Glen Cove Road.) Similarly, the westbound entrance is made from only the westbound side of NY 25. Although this does allow access from both directions of Glen Cove Road, it does not allow entrances from the west on NY 25. It is not unusual for a reverse-turn movement of this kind to be omitted from interchanges in urban and suburban areas. One other entrance available here is from Glen Cove Road to the southbound Meadowbrook Parkway.

Also shown in this image is the grade-separated Y-split between NY 25 and NY 25B. Notice again that an eastbound-to-westbound movement is omitted for both highways, although Glen Cove Road intersects them just west of the split and allows for U-turn movements. This type of split is one of the simplest interchanges, found commonly in rural and suburban areas, with or without the grade separation (see Week 34 and Week 35 for other types of Y-splits).

Northern State Parkway and
Meadowbrook State Parkway at Steve Anderson's
Andrew Kirschner writes:
"Before 1988-91 [see map], when this interchange was converted to the T-format we now know, there was no westbound Exit 31A, and no direct access from the westbound Northern to the southbound Meadowbrook. To get to the Meadowbrook, you had to exit southbound at Glen Cove Road (on a ramp that was eliminated with the reconstruction) then get back on the Northern State were deposited onto the deceleration lanes leading to the Meadowbrook. At any rate, this old configuration also created a numbering redundancy. Westbound there were three exits for Glen Cove Road: Exit 31 north...on Glen Cove Road...Exit 31 south...on Glen Cove to Meadowbrook Parkway, then Exit 31 again for the exit that led, and still leads, to both ways on Glen Cove Road."

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