{"format":"cadcraft-library-item","format_version":1,"uuid":"249eee2f-730b-4408-aadd-607f488ce075","version":1,"name":"United States: AASHTO crest curve K by design speed","kind":"regulation","category":"regulations/building","description":"Minimum K for crest vertical curves (stopping sight distance) by design speed in km/h. Entered from memory of the published table and NOT confirmed against the book. Check before relying on it.","maker":"","model":"","ifc":{"class":"IfcControl","predefined":"NOTDEFINED"},"plan":{"layers":[],"entities":[]},"body":null,"params":{},"regulation":{"format":"cadcraft-regulation-pack","version":1,"id":"us-aashto-sight","name":"United States: AASHTO crest curve K by design speed","jurisdiction":{"country":"US","level":"country","region":"","name":"United States"},"base":null,"edition":"AASHTO Green Book (metric), stopping sig","in_force":null,"review":{"state":"unchecked","note":"Minimum K for crest vertical curves (stopping sight distance) by design speed in km/h. Entered from memory of the published table and NOT confirmed against the book. Check before relying on it."},"authority":"model-code","source":{"name":"AASHTO, A Policy on Geometric Design of Highways and Streets","url":"https://www.transportation.org/","date":"","checked":"2026-10-28"},"maker":null,"price":null,"criteria":[],"tables":{"sight":{"kind":"sight","clause":"Green Book ch. 3","label":"Crest K by design speed","note":"Not confirmed against the standard.","data":{"unit":"km/h","speeds":[30,40,50,60,70,80,90,100,110,120],"crestK":[2,4,7,11,17,26,39,52,74,95]}}},"rules":[{"id":"road.crestk.min","applies":"road","op":">=","unit":"ratio","clause":"Green Book ch. 3","label":"Crest curve K (length per percent of grade change)","note":"The minimum for the alignment's design speed, from the table. Not confirmed against the standard.","value":1}]},"source_attrs":{},"license":{"id":"CC0-1.0","holder":"CadCraft","attribution":"“United States: AASHTO crest curve K by design speed” by CadCraft (https://www.transportation.org/), CC0 (https://creativecommons.org/publicdomain/zero/1.0/)","url":"https://creativecommons.org/publicdomain/zero/1.0/"},"provenance":{"library":"librarycraft","item":"249eee2f-730b-4408-aadd-607f488ce075","version":1,"sha256":"073da377f486996394378bf6eeec1bddc85f9cfee81eeefa76a24692009af625","source_file":"us-aashto-sight.json","source_sha256":"bb976cd85afe8f43c3dc9516bd1c65393be0469c0cac0d94dbf028337108b322","published_at":"2026-11-09T04:16:11Z"}}