The only defence for the citizen is to be else where before the kablammo starts. Yes, you can hunker in the bunker; yes, the rad count drops rapidly with time. You can can take some pretty heavy fall-out with even moderate preparation, even improvised measures, if you're lucky, have a deep basement and a modicum of time to improve your position re: shovelling a minimum three foot packed earth berm around exposed foundations and overheads, improvising filtration, having food and water for a minimum of two weeks? A month?
Then what? At two weeks on, the rad count has decayed down to just sub-lethal for short periods of exposure. You are still taking a cumulative dose that will add up to bad trouble in short order. So, forget about sortieing out to forage. Unless your hole has the highest protection factor, you are going to be taking a cumulative dose that will leave you incapacitated. Unless you are able to wait out years in the hole, you will be running out of food and water, hygiene and sanitation will have become impossible, your immune system degraded, the door wide open to the usual outriders of disaster.
So, once the rad count has decayed enough to permit it, you are going to have to make the run through gamma country to get out, and you'll have to get out before you fry. You'll be exfiltrating on foot, unless you're lucky; over roads damaged or choked with wreckage and irradiated, mangled, desperate refugees and such psychotic, armed bandito's as the policeman. (See: Aftermath of Katrina, or any cop on a good day). Bridges, refineries, railyards, airports and dams are all prime targets, you may not be able to get anywhere.
I say exfiltrate because your state will have had time to place a cordon sanitare to control refugee movements from strike areas as the civil defence (harharhar) and remnants of the state control monad will be long past trying to 'help', and will be fighting for survival (see: Aftermath of Katrina, add radiological mayhem, fear and panic, breakdown of civil order, roving bands of war-lord cops.) You will have to fight your way out, all while taking that cumulative rad dose.
Best be elsewhere before the flash comes. We all dodged a bullet in the last election, but this is a very temporary reprieve, and I have total confidence that this mess is beyond resolution. The pooch will be screwed, the goat will be fcuked.