There are some references in the Wikipedia article on Induced Demand. Most of the cited cases deal with heavily trafficked roads being removed and demand decreasing as a result.
I find the examples on wiki a little sketchy and some are flat out anecdotal.
I do agree it will increase the total traffic as you improve the system but the concept it can ever make it worse or the same in the entire system doesn't make sense.
Peoples need to travel by car is not totally fluid. Jobs stay the same and many people catch public transport for reasons other than convenience.
I'm not sure I've heard the claim that adding capacity actually makes traffic worse other things being equal. It's more that, as you say, people will time-shift, take alternate transportation, take a different route, move, change jobs, etc. to keep a commute under a particular time.
It's sort of another version of the "work expands to fill the time allotted to it" maxim.
And if it's not commuting we're talking about, some people will just choose not to drive into a city for dinner, etc. because it's too much of a hassle.
https://en.wikipedia.org/wiki/Induced_demand