|
|||||||
|
|
|
|||||
|
|
|||||||
Interchange Index
Overview: Interstate 495 runs east to west through this interchange, while Interstate 295 runs from north to south. This interchange is marked as exit 4 on I-295 and exit 27 on I-495.
Interchange Description: This interchange, although very unique, is actually quite simple. It is a semi-directional interchange, meaning that each pair of off-ramps begins as one ramp and then splits into two. Each roadway then has two seperate entrance ramps, except for I-295 southbound, where the two onramps merge together before joining the mainline.
History: Although the ramp arrangement itself has not changed much over the years, the routes going through it have. The Long Island Expressway through the interchange is now completely I-495. The section east of this interchange was called NY 495 before 1983, and NY 24 before 1962. The Clearview Expressway, running north-south, also has changed numbers; before 1974, it was known as I-78. This numbering was chosen because of a proposal (around 1970) to extend it southward to the Nassau Expressway, which was also I-78 at the time.
Advantages: This arrangement has quite a few advantages. First of all, it is a complete four-way interchange which involves no weaving; this is not as common as might be thought. Secondly, traffic can exit and enter directly from the mainline. At many other New York City interchanges, traffic has to enter a service road before exiting to the ramps themselves. There are no left exits in this interchange, which is also a major advantage.
Disadvantages: One of the largest disadvantages of this ramp configuration is its cost. There are four bridges present in this design that would have been eliminated in a typical cloverleaf configuration. Also, I-495's service roads have to cross the I-295 mainline and ramps, and the eastbound service road has a seperate underpass for I-295's northbound offramp. When exiting from I-495 eastbound and I-295 northbound, the offramp's split is backwards (the right fork leads to a left turn and vice versa).
|
|