Oh, goodness, the Aialak fjord/glacier. What an unbelieveable, beautiful spot. If you can find a way to go there, do it.

As for traffic between Anchorage-Seward: Like someone else here, I took the Alaska RR, which was a wonderful little trip. Probably more enjoyable than a car, though also probably longer. Beware that an enormous amount of the traffic between Anchorage and Seward is bus traffic carrying cruise passengers. Cruise ships hold upwards of 1500-2000 passengers, almost all of the passengers are bussed between Anchorage and Seward, and each bus holds no more than 42-44 people. You do the math.