Whatever you do, don’t struggle against it. As you can seen in the diagram most riptides lose strength eventually. As soon as you get to that point swim parallel to shore until you get away from the riptide zone (most often its only a few feet wide anyway)
Try not to steer to much. You want to ease the car onto the shoulder as carefully as possible. This is why its best to drive with two hands on the wheel and stay alert. The worst thing that can happen is to be taken by surprise and then jerk the wheel.
Another one of the those oh-well-it-was-a-good-life situations, this one is actually survivable assuming you are out of the blast radius. Of course it goes without saying, but if you have warning, take cover, preferably underground. If you are in an exposed area, hit the ground and cover your head as soon as you see the blast (don’t run!!) as it could take up to 30 seconds for the shockwave to reach you. Speaking of the flash, don’t look at it! It will blind you guaranteed. Once the initial blast has occurred, flee at your own risk. Remember, there will be gridlock and depending on the direction of the wind that radiation is coming for you. If you have a good hiding spot (underground) your best bet could be to wait for a rescue.