That aside, the logic is fundamentally bizarre. The basic theory of induced demand is that new highway capacity will initially lessen congestion (and associated time-costs) which would then attract new users, thereby canceling out the original capacity addition. The problem with that is that it can be used to claim anything causes highway demand to rise. As you stated, traveling by car or by public transit "accomplishes exactly the same things" and they have exactly the same effects on demand. If you build a subway next to a highway, and people initially switch to it, by the logic of "induced demand" more people would then take advantage of lower congestion on the highway. Therefore we shouldn't build subways. Therefore we shouldn't build anything because people will most likely use it.