Just ask the gas station attendant where you can throw someone else's garbage. Please don't stuff it all in the can by the pump because nobody else will have room for their "in car" garbage. Every gas stop that I have ever asked has had a dumpster that they would love you to put the large bag of garbage. You have done a great thing by picking up other people's trash. Now, make the the employees job easier by throwing it away properly. I will thank you fir the guy that has to empty the cans.