Stack interchange

[2] Since then, the California Department of Transportation (Caltrans) has built eight more four-level stacks throughout the state of California, notably the Judge Harry Pregerson Interchange, as well as a larger number of three-level and four-level stack–cloverleaf hybrids (where the least-used left-turning ramp is built as a cloverleaf-like 270-degree loop).

The first four-level stack interchange in Texas was built in Fort Worth at the intersection of I-35W and I-30 (originally I-20) near downtown.

[3] Improvements to the old Mixmaster over the past 60 years include an upgrade to a Texas-style five-level stack exchange (see below).

One of the first four-level stack interchanges in the northeastern United States was constructed in the late 1960s over I-84 in Farmington, Connecticut, for the controversial I-291 beltway around the city of Hartford.

This was necessitated by the inadequacy of the original configuration that was caused by the rerouting of I-95 onto the Beltway after its cancellation within Washington and points north.

In Thornton, Colorado, there is another stack serving I-25 and E-470 at its northern end as it continues west as the Northwest Parkway.

In Greece, there is also one[citation needed] four stack interchange near Metamorfosi, which connects the A1 and A6 (Attiki Odos) motorways.

The junction of the A19 and A66 in Teesside uses a three-level variant, with a 270-degree loop allowing southbound A19 traffic to exit to the westbound A66.

The frontage roads usually intersect with traffic lights and are similar to a grid of nearby one-way streets.

[5] Others can be found at the interchanges between State Highway 121 (SH 121) and the Dallas North Tollway, SH 121 and I-35E/US 77, I-30 and I-35W, I-30 and President George Bush Turnpike and others which are technically five levels but do not fit under a Texas-style stack configuration (i.e. the extra level being located away from the central stack or existing in only one direction).

In 2011, the previously four-level stack interchange between I-610 and I-10 on the city's east side gained a new (though long-planned)[8] level of complexity with the opening of four ramps connecting the new US 90 (Crosby Freeway) to the east, featuring direct movements for the new freeway to and from the southeast quadrant of I-610, to westbound I-10, and from eastbound I-10.

Another case is where connection to nearby arterials suggests that another level may be useful, thus making the interchange more complicated but easier to use.

In the Atlanta area, a side ramp forms the fifth level of the Tom Moreland Interchange, colloquially known as Spaghetti Junction, found in DeKalb County, Georgia.

There is a six-level stack on the Yan'an East Road Interchange (Chinese: 延安东路立交) in Puxi, Shanghai, with no dedicated HOV/bus/truck lanes.

The story is that after several construction accidents, a monk suggested the nine-dragon be welcomed with a bas relief sculpture depicting the dragon.

[citation needed] An unusual six-level stack is located at the junction between Interstate 35E and I-635 in Dallas, Texas, and does not contain any service or frontage roads.

A single ramp leading from I-635 westbound to I-35E southbound weaves underneath the I-635 eastbound bridge, making the interchange six levels.