It's more elastic than you might assume. There's a phenomenon called traffic evaporation, when a major roadway is closed or diminished (even unexpectedly), people adjust their travel behavior such that travel times stay relatively constant.

Los Angeles has many such examples, one recent and well studied one was the closure of the 10 freeway after a fire.

it’s actually been shocking to me how elastic it is. it frankly pisses me off how much time i spend in traffic behind people who are apparently fully deterred by a mere $1-2 fee. we should absolutely have faster lanes for people who are driving for higher value reasons.

It totally is. Demand can be induced. You can build more highways/roads, you can build more transit options, you can decide how to design roads and handle zoning, affecting how far people go (where are their jobs and stores?), you can decide to build protected bike lanes or build prioritized bus lanes, etc.

All of these factors and more affect demand for transportation.