No election campaign in any country is complete without ambitious promises to build stuff, and Tsai's is no exception.
A few weeks ago Tsai proposed several transportation-related projects for Xinbei. The most ambitious was extending the MRT's Muzha line east from Taipei Zoo and the TRA's Pingxi line west from Jingtong so the two will meet in Shenkeng. Tsai claims this will turn Shenkeng into a transportation node, and will make it easier for tourists to visit Shenkeng and from there visit other tourist spots in the northeast, such as Jiufen. Her advisers, she assures us, tell her that it's feasible.
The Pingxi-Shenkeng idea strikes me as really bad, even by pie-in-the-sky pork barrel standards. The point of rail is that it can move huge numbers of people while using less energy and much less space than other forms of transportation. If you're not going to get a huge number of people on a rail line, there's no point in spending the huge amounts of money it will cost to build. An extension of the Muzha Line could make sense since despite Shenkeng's low population, most people live in a single narrow valley that leads right to the current terminus of the Muzha Line. There's a good possibility many of those people would choose to take the MRT instead of drive.
An extension of the Pingxi Line however is unlikely to attract enough passengers to make up for its cost- and given how narrow and winding the Jingmei River Valley is between Shenkeng and Pingxi, that cost would be very high. Tsai suggests that such a line would make it easier for tourists to visit both Shenkeng and Pingxi, and even suggested it would help with traffic around Jiufen. But the number of tourists wishing to travel between Shenkeng and the Northeast Coast or Pingxi cannot be very large- presumably most people would choose one or the other even if transportation between the two was more convenient. If there was actually demand for this there would presumably be more than one bus an hour between Shenkeng and Jingtong, and these buses would presumably be crowded- but past Shenkeng, they're far from crowded. And even a Shenkeng-Pingxi rail line was crowded with tourists, without enough locals to use it, it would be empty on workdays. But there is nothing but a few hamlets between Shenkeng and Pingxi- almost certainly too few people to justify a rail line.