As many as six bus routes could be eliminated, as a part of RTD's proposed temporary service reductions to deal with operator shortages. Some bus routes would also cut back under the plan that was put in front of the transit agency's board of directors yesterday. Other changes would include some light rail routes. The D-Line would lose service on the weekends, but the C-Line would be expanded during that time to help out. The board could take action as soon as March with an implementation of the plan in May.