I can't believe they are not just letting RTD handle this project! RTD already has a robust training program for the flag-persons that will be required for the new commuter rail line. The agenda for their next meeting is heavy with the Longmont/Boulder "segments":

http://colorail.org/wp-content/uploads/2017/09/Agenda-September-23-2017-release.pdf

There will also be a train movie!