How common is credit/debit card usage in USA?

Posted by Rowdy_Roddy_2022@reddit | AskAnAmerican | View on Reddit | 91 comments

I've got a fee-free credit card which I always like to use when abroad. I know I'll need some cash with me (it's a 3 week trip hitting Washington DC, Vegas, San Fran and LA) but I am trying to figure out how much. If you eat at a restaurant and pay by card can you normally add your tip on card? Same thing for taxis? Do ATMs charge a fee? What about public transport? Are there any of the locations noted above which are less card friendly than others? Do you use chip & pin or the less secure swipe and sign?