I read a story a long time ago and I'm trying to find it again because it has stuck with me all this time. I'm guessing I read it in an anthology in the late 60's or early 70's.
The scene is a family returning from a beach vacation and they are stuck in a long traffic jam at a tunnel. The father complains it's not worth it and they'll never do this again.
They are extremely nervous, and the reader learns their lives are at stake. The government does population control by randomly closing the ends of the tunnel and euthanizing the everyone in the tunnel at that time. You are only at risk if you take a vacation.
The family barely makes it thru (the gate closes on the car behind them) and the story ends with the family declaring what a great vacation it was and they can't wait to do it again next year.
What was the title and who was the author?