Free-flow interchange
In article Free-flow interchange we are going to delve into a topic that concerns us all in one way or another. Regardless of our age, profession or personal interests, this topic is relevant to everyone. Along these lines we will explore different aspects, data and opinions related to Free-flow interchange, with the aim of providing a broad and complete vision of the subject. Whether we are familiar with Free-flow interchange or it is the first time we are hearing about it, this article invites us to reflect, learn and question our own understanding of Free-flow interchange.
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A free-flow interchange is an interchange in which all roads are grade-separated, and where movement from one road to another does not require the driver to stop for traffic (for example, the interchange may not include traffic lights or unsignalized at-grade intersections). Free-flow interchanges are less likely to induce traffic congestion than non-free-flow, but are typically more expensive both in money and in land.
Some free-flow interchanges bring additional problems such as weaving or passing lane/fast lane exits (i.e. left exits in areas with right-hand traffic, and vice versa) that may be necessary to avoid additional costs, but lead to congestion and accidents and ultimately to an upgrade to another type of interchange.
A free flow interchange design called double crossover merging interchange (DCMI) has received a patent.[1] The DCMI includes elements from the diverging diamond interchange (DDI) and the standard diamond interchange. It eliminates the disadvantages of weaving and of merging into the outside lane from which the standard DDI variation suffers.
Examples of free-flow interchanges
- Stack interchange
- Cloverleaf interchange
- Trumpet interchange
- Cloverstack interchange
- Directional T
- Semi-directional T
- Turbine (whirlpool) interchange
Examples of interchanges that are not free-flow
- Diamond interchange
- Partial cloverleaf interchange
- Three-level diamond interchange
- Diverging diamond interchange
References
- ^ "United States Patent 8,950,970: Double Crossover Merging Interchange". United States Patent and Trademark Office. February 10, 2015. Retrieved August 4, 2015.