I get what you're saying, but I'm not sure you realize just how much that would hurt people. Europe is much more densely concentrated and has far better public transit options. Many parts of the US are extremely rural. My nearest grocery store is a 30 minute drive away. There are no stores in walking distance at all. There are no sidewalks. There are no busses, trains, or cabs in my area, and that is not wildly uncommon.
If costs of gas doubled, at least without viable alternatives, it would absolutely bankrupt people. And it would disproportionately impact poor people in rural areas where it's very common to commute to work 30-60 minutes of driving is a common commute. While it varies by state, US federal minimum wage in the US is $7.25/hour. Many people commute for work, and an hour drive one way is also not uncommon.
Let's take 7.25 an hour x 40 hours = $290 before taxes.
We'll keep it simple and say a person uses only 1 gallon of gas per day to get to and from work which, at $8 a gallon x 5 days a week = $40. Just that travel to and from work and no other travel at all (or maintenance on the vehicle) would be 14% of pre-tax income.
So many things need to change so I understand the perspective, but I think it's really important to consider the widespread impact. Obviously the US has a lot of issues contributing to this situation.