Any discussion of the future of mass transit (“The Little Monorail That Could,” 3/7) should include at least a passing reference to personal rapid transit, or PRT. PRT is a network of small cars operating on a network of slim elevated guideways with off-line stops.

The advantages of small, personal cars operating on a wide network of guideways, rather than heavy, high-capacity trains scheduled to operate along a corridor are:

* Stops are much closer and more convenient than existing Metro stops, typically with a maximum walk of a quarter-mile to any location within the network.

* Direct stop-to-stop service means no transfers.

* Off-line stations allow cars to wait for passengers rather than requiring passengers to wait for trains.

* Individual cars allow privacy and safety for parties of up to three people.

* Capital and operating costs allow system to operate at a profit

without subsidies.

I encourage all people interested in the future of the Metro system to check the following Web sites: www.taxi2000.com and kinetic.seattle.wa.us/prt.html.

College Park, Md.