The researchers focused on complementary effects between high-speed rail and EVs. If people can use rail for long-distance trips, it becomes easier to choose EVs that typically have shorter driving ranges for everyday use [...]

Using the fact that high-speed rail connections came at different times across cities, it compared EV sales trends before and after connections and controlled for other factors such as local economies and industrial policy [...]

Consumer purchasing patterns also changed. EVs sold after high-speed rail connections tended to have shorter maximum driving ranges, and the average transaction price fell by about 6.37 percent

The news doesnt link to the actual article, but I think it is this one:

High-speed rail and China’s electric vehicle adoption miracle (DOI)