Eight new bus routes, six of them offering free service, were initiated in Montgomery County this week, in part to help ease traffic on I-270 and Rte. 29, county transportation officials announced.

Among the services:

Germantown commuters can park free in a new commuter lot on Germantown Drive near Waters Landing Drive and ride one of two free express buses, officials said. A bus marked 67 is providing express service to the Shady Grove Metrorail Station.

A bus marked 66 is running from the new parking lot to Piccard Drive and Research Boulevard in Rockville.

No. 66 will also make one morning and evening return trip to the Rockville Metrorail Station.

Ride-On buses are running morning and evening to meet commuter trains at the Germantown Railroad Station. Buses marked 68 serve the Waters Landing area and buses marked 69 will serve the Gunner's Lake area.

Montgomery Village has a new morning and evening express service route between the Montgomery Village Mall and the Shady Grove Metrorail Station. The new bus is marked 65; an inbound trip costs 60 cents. The return trip is free with a Metrorail transfer; without a transfer the return ride costs 60 cents.

In Silver Spring, Metrobuses marked Z-9 and Z-11 are providing free morning and evening rush hour service between the new park-and-ride lot at the corner of Briggs Chaney Road and Gateshead Manor Way in the Fairland area and the Silver Spring Metrorail Station. Parking is free in the 400-car lot, which is located about a mile east of Rte. 29.

Rockville has a new lunch-hour bus service called the Shady Grove Shopper. Ride-On buses marked 41 will run between the Ride-On Operations Center at 16640 Crabbs Branch Way and the Rockshire Shopping Center at Hurley Drive and Ritchie Parkway. The fare will be 25 cents one way.

For more information, call 251-2225.