> They should have used the existing right of way on I5, no stops between SJ and LA.

If you build high speed rail, you want ridership. Adding Fresno to the line takes the distance from San Jose to LA from roughly 340 miles to 366, adding roughly[1] 7 minutes to the route for express trains - hardly a dealbreaker. This also allows other trains to stop at Fresno and Bakersfield, adding a population of ~1million to the route, increasing its' viability.

A straight shot down I-5 would save a few minutes but severely limit the economic and social benefits it will have by increasing access to the central valley.

[1] 26 miles/220 miles per hour = 7.1 minutes. Trains that stop will add a few more minutes. Equivalent systems in every country with HSR have a mixture of express trains and local trains in this situation

Nitpick: on a 26 mile stretch with stops at both end, that train will do closer to half its top speed. It has to decelerate and accelerate one more time. I think that will add closer to 15 minutes to the time on the full stretch.

But yes, they need riders, and thus intermediate stops. Most train passengers don’t ride the full track, just as most highway drivers don’t ride the entire highway.

Yes, that is why I explicitly noted the "express train" thing in my footnote. The route itself is longer, so a direct train will take a little bit longer. A local train that stops will add more time.

Bigger nitpick: 220MPH is the top speed. Average speed is going to be more like 130MPH, so more like 12 minutes (before considering the time for any stop).

What is the speed on the central section though? The average is very heavily weighed down by track sharing on the SF end

And it will have to slow down through Fresno even it it express and not stopping

I5 doesn’t go through the Bay Area.