Free Web Hosting Provider - Web Hosting - E-commerce - High Speed Internet - Free Web Page
Search the Web

Interchange Index

Overhead Picture from terraserver-usa.com

Overview: The Potomac River runs along the west side of this picture. I-66 crosses it on the Theodore Roosevelt Memorial Bridge, along with US 50. At the interchange at center, I-66 turns northward, while US 50 continues eastward on Constitution Avenue. The freeway leading eastward, parallel to and north of US 50, is E Street; this freeway runs for only a few blocks before ending. The street leaving the southern edge of the photo may (?) be Independence Avenue, which leads to the Lincoln Memorial at the west end of the Mall. The large white building along the river is the Kennedy Perofrming Arts Center; between it and the Potomac is the Rock Creek Parkway, which really has no part in this interchange.

Interchange Description: This is really a combination of a four-way, incomplete interchange and a standard three-way semi-directional "T." The four-way interchange lies at the southern end, and is incomplete to the point of really being nothing more than another semi-directional T, providing full connections between the west, north, and south, with two extra ramps to provide connections from the west to the east. Connections from Constitution Avenue and other local streets to I-66 north, Independence Ave. south, and the E Street Freeway are available through local streets.
The ramps connecting the bridge to I-66 north (which actually carry I-66 mainline traffic) split as they enter the northern half of the interchange. For EB traffic, the right fork merges with another ramp from Independence Avenue and leads to E Street; the left fork merges into the freeway which then becomes I-66. WB traffic on I-66 (which is actually moving south at first) can exit I-66 on the left side (while staying on the mainline of the freeway itself) to reach Independence Avenue and the Lincoln Memorial. Another left exit serves E Street, after which a long exit ramp allows traffic to reach the Kennedy Performing Arts Center and the Rock Creek Parkway. The remainder of the traffic joins US 50 and crosses the Potomac.

Advantages: The majority of the traffic here is moving E-W or N-W and vice versa; that said, the interchange is fairly well designed. The idea here is not to provide full, equal connections to and from each street involved. Instead, the interchange was built to disperse a large amount of traffic, entering on I-66 from the west, into the various areas of downtown Washington, and vice versa: to collect the traffic from these areas and bring it smoothly back over the Potomac. It performs this basic function without any weaving, and in a reasonably small area.

Disadvantages: This interchange is one of the few with no major disadvantages - the only real problem is the number of left exits and entrances, and this isn't that high, anyway. Wow - when am I ever at a loss for critcism?

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