The North Bay’s State Route 37 is becoming a toll road. The California Transportation Commission has approved the Metropolitan Transportation Commission’s request to add a toll to the road, which links Highway 101 in Novato with Interstate 80 in Vallejo. Wednesday’s vote does not list the toll amount, however. The approval has two amendments attached to it. The Metropolitan Transportation Commission must consider future toll discounts based on regional income levels rather than federal income levels. The commission also has to update its guidelines for toll hearings.