Examples of Cant Attainment Methods

View examples of the XML formats you can use for various cant attainment methods.

This section explains the formulas used in some common cant attainment methods.

By Spiral Lengths, and % On Tangents if No Spiral

The following example shows the XML format you can use to calculate transition stations based on spiral lengths. If a curve group does not contain spirals, then a specified percentage of the transition takes place on the tangents.

<CantAttainmentMethod name="by spiral lengths; and % on tangents if no spiral">
<TransitionFormula type="LRtoFC" formula="IF({l}, {l}, {t})"/> 
<TransitionFormula type="LRtoBC" formula ="IF({l}, {p}*{l}, {p}*{t})"/> 
</CantAttainmentMethod>

By Lengths from a Table, and Maximum Cant on Tangents if No Spiral

The following example shows the XML format you can use to calculate transition stations using transition lengths from a table. If a curve group does not contain spirals, then a specified maximum cant value is applied on the tangents.

<CantAttainmentMethod name="by lengths from table; and max cant on tangents if no spiral">
<TransitionFormula type="LRtoFC" formula="{t}"/> 
<TransitionFormula type="LRtoBC" formula ="IF({l}, {p}*{t}, IF({a}&{d}<={a}, {d}*{t}/{a}, {t}))"/> 
</CantAttainmentMethod>