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Interchange Index

Overhead Picture from terraserver-usa.com

Overview: Interstate 95 enters at the southwest corner, and runs towards the northeast corner. Its median gradually widens from almost nonexistent to nearly a half mile. Just to the northeast of this photo, it meets I-295 and I-495 at another remarkable interchange, whose page can be found here. The left entrance from I-295 can be seen where I-95's southbound lanes enter the photo, at the northeast corner. DE 141 runs north-south through the eastern half of the photo. US 202 enters the interchange from the northeast on I-95, and is multiplexed with it until DE 141. It then turns southward, and spends its last two miles multiplexed with DE 141 until it ends at US 13 and US 40. The local road running parallel to and just south of I-95 is Airport Road.

Interchange Description: This interchange is a variation on the venerable cloverleaf interchange. However, while most modified cloeverleafs are modified to avoid weaving between the cloverleaf ramps themselves, this interchange is modified to eliminate weaving between this interchange and the I-95/I-295/I-495 interchange just northeast of it. The following modifications have been made to avoid weaving between the interchanges:

• The ramp from DE 141 northbound to I-95 northbound has been moved from its usual location to another loop in the median of DE 141 and the median of I-95. As a result, it is actually a "backwards" cloverleaf, requiring a 270-degree left turn in place of a 90-degree right turn. The entrance to I-95 is on the left side, which prevents traffic from traveling from DE 141 northbound to I-295. (The ramp to I-295 north actually splits from I-95 south of the DE 141 underpass, and serves as a collector/deistributor road for the two northbound cloverleaf ramps.) The connection to I-295 would be redundant, as it is provided by nearby US 13.
• The ramp from DE 141 southbound to I-95 northbound is in its usual location. However, at the DE 141 southbound bridge, the right lanes of I-95 split off to I-295; the cloverleaf ramp in the southwest quadrant serves I-295 only. I-95 is accessible via a left exit in the median of I-95, which joins the ramp from DE 141 northbound and enters the left side of I-95. I-495 can be accessed from the I-95 ramp with a small amount of weaving.
• The ramp from I-95 southbound to DE 141 northbound is in its usual location. However, the ramp from I-295 enters at the left side of I-95 just as this ramp leaves the right side; traffic would not be able to weave across the I-95 mainline to access this ramp. To give I-295 traffic access to DE 141 northbound, a left exit was built from the I-295 ramp directly to DE 141, inside the median of I-95. This ramp, although probably not marked as such, also could provide access to DE 141 southbound. Instead of I-295 traffic weaving across all of the southbound lanes of I-95 to the cloverleaf ramp to DE 141 southbound, drivers could exit here to DE 141 north, use the northeasterly cloverleaf to enter the right side of I-95 southbound, and then use the northwesterly cloverleaf to exit to DE 141 southbound. It is a circuitous route, but it may be easier than crossing I-95 with heavy traffic.

Missing Connections: Despite the extra ramps present here, there is one missing connection. Traffic traveling northbound on DE 141 cannot access the ramp to I-295 north (which really runs due east.) This connection is provided by US 13, which runs SW-NE between DE 141 and I-295 just SE of this photo.

Advantages: This interchange, had it not been nuilt as it is, probably would have been a standard cloverleaf interchange. This would have been disastrous: not necessarily because of weaving between the cloverleaf ramps themselves, but because of weaving between the eastern half of the cloverleaf and the ramps to I-295 and I-495. By adding the the left exits and modified cloverleaf ramps where they are, a substantial amount of weaving was eliminated.

Disadvantages: As with the I-95/I-295/I-495 junction just to the northeast, there are many left exits and entrances present here. Some, such as the ramp from I-295 to DE 141 north, are not such a big deal because they come from slower-moving ramps. Others, such as the ramps from DE 141 to I-95 northbound, are more of a problem, because traffic is entering the left land of a mainline highway with high-speed traffic. In addition to the downsides of left exits, this interchange has more weaving than a typical cloverleaf on DE 141 northbound. Traffic coming from DE 141 northbound, bound for I-95 southbound, has two incoming ramps to weave across instead of one. Lastly, the interchange takes up a huge amount of space. Here, it was built on a swamp, so space wasn't as big of an issue; in a densely developed area, the design might not be such a good idea.

Corrections? Suggestions? More information is always welcome.
Suggestions for more interchanges to cover on this site are great too.
Contact the author, Dan (known as DanTheMan on misc.transport.road):
twowheel@email.com