I tried to search old posts but it isn't working now for some reason.

I booked my ticket wrong (return too early in the afternoon) so there's no leeway for an unplanned delay, such as a flat tire or heavy traffic. If one barely misses their flight on Southwest, will they allow you to take the next later flight like some other airlines or will they require you to buy an unrestricted coach ticket?

I'm asking this not to be tricky but to decide if I should drive like a madman to the airport or drive normally and have some chance of missing the flight.