In the U.S. state of Minnesota, a legislative route is a highway number defined by the Minnesota State Legislature. The routes from 1 to 70 are constitutional routes, defined as part of the Babcock Amendment to the Minnesota State Constitution, passed November 2, 1920. All of them were listed in the constitution until a 1974 rewrite. Though they are now listed separately in §161.114 of the Minnesota Statutes, the definitions are legally considered to be part of the constitution, and cannot be altered or removed without an amendment. Legislative routes with numbers greater than 70 can be added or deleted by the legislature.
Until 1933 Constitutional Routes corresponded exactly to the number marked on the highways, but this is no longer necessarily the case. In fact it's common for CR highways to be composed of several different trunk highways. When the U.S. Highway system was created in 1926, many of these roads were made up of one or more U.S. highways. Today, they now use a mix of Minnesota state highways, U.S. highways, and Interstate highways.
Constitutional Route 1 is currently one of the most complex routes, composed of:
However, the route can be considered to be superseded along almost its entire length by Interstate 35 (and I-35E) and Minnesota State Highway 61. By contrast, Constitutional Route 58 still has the same marked number and extent that it did in 1920.
There is some ambiguity in how literally the Minnesota Department of Transportation must interpret the constitutional routes. In some cases, the routes no longer directly serve communities they were once designated for, but are routed along nearby highways instead.