Interchange Index

NJ 24, NJ 124, & John F. Kennedy Parkway
Chatham, NJ

Overview: NJ 24, which is a limited-access freeway for its full length, runs from north to east. NJ 124, a 4-lane surface highway, comes in from the west and leaves the interchange as the service roads on either side of NJ 24. The north-south highway, which curves to the east towards the north side of the interchange, is the John F. Kennedy Memorial Parkway, a four-lane surface highway with at-grade intersections. The Passaic River runs just west of this interchange, as can be seen in the aerial photo. The large white building just above the center of the photo's east side is the Short Hills Mall.
This exit is numbered as Exit 7 from NJ 24 eastbound, and the westbound exits are numbered, from east to west, 7C, 7B, and 7A.

Overhead Picture

Interchange Description: This interchange is a five-way interchange which appears, at first sight, to be missing a few connections. However, because of its pseudo-cloverleaf design, connections are available to and from all five directions, although some involve traversing up to four cloverleaf loops. These convoluted connections are listed below.

In addition to these connections, it seems at first glance as if there is a pair of redundant ramps that serve the same function. These are two ramps from the Kennedy Parkway southbound, which both appear to lead to NJ 24 eastbound. However, the first (which splits from the NJ 124 westbound ramp at the NJ 24 bridge) actually leads to the NJ 24 EB mainline, while the second (a loop ramp in the southwest corner) leads to its service road, NJ 124 EB.

Advantages: One of the greatest advantages of this interchange is that its maintenance and construction is cheaper than most other five-way directional designs that I have seen. By eliminating all bridges except those that are absolutely necessary, NJDOT kept the cost down at the expense of traffic flow and interchange size. This size wasn't quite as much of a problem here - as you can see in the aerial photo, efficient use was made of the southeasterly loop ramp by nestling an office building inside of it. In the suburban area, nearby residents and employees would generally rather have a sprawling, grassy cloverleaf outside their window than a towering four-level stack.

Disadvantages: One major disadvantage here is the fact that multiple loop ramps must be used to complete some connections. Four loop ramps for the NJ 24 EB -> NJ 124 WB connection is absurd - from the first exit from NJ 24 to the merge into NJ 124, drivers must drive 1.6 miles. Also, the abundance of loop ramps means that weaving is rampant in this design. This problem is not as bad as it could be; by using NJ 124 as a pair of frontage roads east of this interchange, much of the weaving that would ordinarily take place on the NJ 24 mainline is relegated to collector/distributor roads. The worst case of weaving occurs on the Kennedy Parkway under the NJ 124 eastbound bridge, where traffic coming from NJ 24 eastbound has to quickly cross traffic from the parkway going to NJ 24 eastbound.


Corrections? Suggestions? More information is always welcome.
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