Among sources for vanpooling information:

* Commuter Club, (202) 783-7665. The metropolitan area ridesharing program run by the Council of Governments. Computer matching service. A tape recording asks pertinent questions -- and records answers -- concerning your ridesharing situation. Caller receives a printout listing other drivers/riders living in your area and working near your place of employment.

* CPT & Associates, 301-267-9548. Third-party operation. Call Phyllis Thompson.

* Maryland Van Pool Association. (Now being organized.) Call Barry Sax, acting president, at (301) 949-8436 or Tom Pogue at (301) 251-2145.

* Montgomery County Ridesharing Information. Tom Pogue, coordinator. Hotline (recording), (301) 770-7665; weekday hours, (301) 251-2145.

* MTA Ridesharing Information, in Maryland, 1-800-492-3757; elsewhere, 301-659-2997, -2998, or -2999. Maryland statewide computer matching service.

* National Association of Van Pool Operators, 615-966-4507, Ed Marks, executive director. 12208 W. Kingsgate Dr., Knoxville, Tenn. 37922.

* National Ridesharing Information Center, (202) 426-0210. Information on vanpooling and ridesharing in general. Also refers people interested in ridesharing to the appropriate agency matching riders and drivers. Two booklets of possible interest "Starting a Driver-Owned and Operated Vanpool" and "How Ridesharing Can Help Your Company."

* Transportation Total, Inc., (703) 768-3050. Third-party operator. Call Lew Pratsch. (703) 768-3050, evenings.

* Van American Network, (301) 468-6640. Third-party leasing. Call Mitch Fanaroff.

* Vanpool Services, (202) 862-5438. Third-party leasing. Call Dwight Jarvis.

* Virginia Van Pool Association. Call 703-670-9000, evenings.