What circulation systems are possible?*

There are a number of circulation configurations possible with single and double helix ramps. These include end-to end, camel-back, three-bay side-by-side-, and four-bay side-by-side helices. There is another possible circulation configuration, the split-level arrangement, but these are becoming much less prevalent. Further at airport parking facilities, speed helix ramps are common. This is because the cost and the need for moving vehicles efficiently can be justified.