Here's a third extension to the Graveyard ride (Great Taipei Rides II) taking Xinguang Rd. (新光) Rd. up across the hills and back down to Zhengda on Wanshou Rd (萬壽). Map.
2009-5-18 Update: the landslide on lane 74 is now under some kind of construction and gates have been installed on either end. The gate on the lower side is chained but a large gap makes it possible to slide your bike under. The top gate was unlocked. Probably something to do with the efforts to repair the Maokong Gondola.