Yeah, I wouldn't think California would be a good place to have high speed rail due to geography. Also, this brought up a question to my mind, what is the average speed of Amtrak trains when traveling through Flat Lands? They mentioned Acela in this short, but I was wondering in terms of average.
The average Washington to New York speed on the Acela is 80-something mph, although it commonly runs 110-125 mph and maxes out for a few miles in New Jersey at 135 mph . The average Northeast Regional for the same route is 70-something mph, never exceeding 125 mph, but otherwise with top speed similar to the Acela. It's slower because it makes more stops and the trains don't accelerate as quickly as the Acela.
The average speed between New York and Boston is slower,particularly between New Rochelle and New Haven. But even east of New Haven, curves and grade crossings limit maximum speeds to ~90 mph. In Rhode Island and parts of Massachusetts, the track allows the Acela to go 150 mph in some short stretches.
The average point to point speeds on most of the other Amtrak routes are 45 to 50 mph, even though the maximum posted speed can be as high as 79 mph. But you'l rarely go that fast crossing the mountains because most of the routes have a lot of curves. The routes were laid out in the 19th and early 20th century for the most part, and building extensive tunnels, cuts and really long viaducts to straighten out a rail line for 100 mph (or even 70 mph) operation was not exactly a cost-effective proposition using the technology of the time.
My average point to point speed when I take a road trip is 50 mph if I drive on Interstate highways. Sure, I can drive up to 70 mph, even 80 in a few parts of Texas, or if I'm sure no traffic cops are around, but I need to stop periodically to use the restroom, eat meals, and refuel the car. Not to mention slowdowns from traffic congestion, etc.
If Amtrak service can consistently provide 60 mph point to point average speed, I think it can compete very well with cars and buses on speed. It doesn't really require cutting edge technology, it requires spending money on infrastructure improvements to increase capacity and reduce congestion.