Usually snow is not something toll-road operators welcome. It keeps people off the roads. But in Colorado the rules about snow and roads are a little different. The state is one of a handful in the United States that is increasingly turning to private investment to help deliver and maintain infrastructure, including toll roads and lanes.

In recent years, Denver has used a P3 (public/private partnership) to revamp its downtown Union Station train station, and toll lanes have been added to Highway 36 between Denver and Boulder, as well as along Interstate 70, which runs from Denver to many of the major Rocky Mountain ski resorts.

Outside of Colorado, in the rest of the United States, toll roads and lanes also are experiencing something of a renaissance. Moody’s Investors Service expects a 3 percent increase in traffic and a 5 percent jump in revenue in 2016 for the 45 toll road operators the ratings agency tracks; it has changed its outlook for the sector from “stabl