Editing Railroad switch (section)

== Speeds over turnouts ==
Train speeds over turnouts are governed by a number of factors. As a general rule, the smaller the crossing angle of a turnout, the higher the turnout speed.
Turnouts are usually rated numerically, which represents the ratio of divergence per length as measured at the frog. A rule of thumb{{according to whom|date=April 2025}} is that the rated speed of a switch (in miles per hour) is twice the numerical rating:
* {{abbr|no.|number}}&nbsp;15: {{convert|30|mph|km/h|abbr=on}}
* {{abbr|no.|number}}&nbsp;20: {{convert|40|mph|km/h|abbr=on}}

Higher-speed turnouts in the United States include:<ref name="63 FR 39343" />
* {{abbr|no.|number}}&nbsp;26.5: {{convert|60|mph|km/h|abbr=on}}
* {{abbr|no.|number}}&nbsp;32.7: {{convert|80|mph|km/h|abbr=on}}

Such specifications, however, are by no means universal: 1:16 is  specified for {{convert|100|km/h|mph|abbr=on|order=flip}} standard-gauge track in Uganda.<ref>{{Cite web |url=https://www.sgr.go.ug/specifications |title=Specifications |publisher=SGR Uganda |website=SGR.go.ug |access-date=25 August 2023 }}</ref>

Turnouts on [[high-speed rail]] lines have much larger crossing numbers than the above, combined with swing noses.