School tokens will not be accepted for Metrobus rides in the District of Columbia during vacations and on weekends starting June 26, forcing thousands of young riders to pay 60 cents for trips that now cost them a dime.

In an economy move, the D.C. Department of Transportation -- which subsidizes discount school fares -- has invoked rules that will permit a 10-cent fare only for students who are certified as enrolled in summer or weekend educational classes, including such programs as the D.C. Youth Orchestra.

Students in such programs will be given certificates letting them buy discount tickets good for 10-cent rides during the summer and on weekends after school resumes in the fall, according to John A. Drayton, deputy assistant director of the transportation department. Metal tokens used during the school year will not be any good for travel until September, he said.

Although intended only for travel to and from school, the use of cheap school tokens for recreational and shopping trips has become a way of life for thousands of young people who, unlike their suburban counterparts, often lack access to cars.

Drayton said ending the use of school tokens on non-school days will save an estimated $500,000 in taxpayers' subsidy of Metrobus fares between June 26 and the end of the fiscal year on Sept. 30, a figure which indicates that close to 10,000 school tokens are dropped in bus fare boxes daily during the vacation. In future years, the school-fare crackdown would save an estimated $750,000 at present levels of adult fares.

Under a law enacted by Congress in 1962, for each school trip the D.C. government pays Metrobus the difference between the 10-cent student fare and the full adult fare. Since the adult fare is now 60 cents, the subsidy for each ride is 50 cents.

However, the days of the 10-cent fare are numbered. The D.C. City Council voted preliminary approval last week and is expected to give final approval next week to an increase to 15 cents sometime in the fall -- the date depending upon procedural determinations -- and to a second increase to 20 cents next Jan. 1. Thereafter, school fares would be one-third of the adult fare rounded downward to the nearest nickel. That means the next school fare rise, to 25 cents, would come whenever the adult fare goes to 75 cents.

In the metropolitan area, the District is the only political jurisdiction that has reduced school fares for student travel on Metrobuses on regular routes. Alexandria and, to a limited extent, the District use chartered Metrobuses in place of yellow school buses for strictly school travel, with no fare collected.

After the District school token restrictions go into effect June 26, similar restraints will be put into effect limiting Metrorail ticket sales to students enrolled in summer programs. Because of the difficulty in monitoring the use of farecards, however, Drayton said student tickets left over from the current school year will continue to be accepted for train travel.