On Sunday, the Regional Transportation District opened a new park-n-ride in Broomfield at 1stBank Center that will serve bus rapid transit lines meant to cut travel times between Denver and Boulder by 15 minutes (via the Daily Camera). It is one of many improvements along U.S. 36 to improve the flow of traffic. Another, but surely less welcome, one could be to increase the number of drivers charged a toll on the highway. The Denver Post reports that a study will be done to determine whether to charge all drivers on the highway, to continue the existing system of charging only single-occupant vehicles in HOT express lanes, or to require vehicles to have at least three people inside to be exempt from a toll. State transportation officials could spend up to $900,000 on the analysis, which comes as U.S. Department of Transportation officials raise doubts that tolled express lanes would be enough to produce the $5 million a year needed to pay off a $53 million federal loan for an express lane project. Variable tolls could also be introduced, tolling only for "critical congested segments" of highways or only during peak travel periods, with no tolls charged at nonpeak times, according to an analysis cited by the Post.