Pretty sure whs1966 means that rail will help the traffic and parking problems, so better to pay for rail than watch the aforementioned problems get worse and worse.

Now, having said that, I don't think anyone believes rail will DECREASE the traffic and parking problems, since population and number of cars per capita are only going to increase over time.  However, giving people the rail option will at least slow that increase, which makes for a better situation overall.

Finally, to Ms. Tugadi's assertion that people are leaving because of rail - GOOD - it's population increase that's the root of all the problems.  I only wish it were fewer people coming in, rather than locals leaving.