Driving from Anchorage to Whittier to play in Prince William Sound? You’ll go through Anton Anderson Memorial Tunnel—the longest (2.5 miles) highway tunnel in North America, and the first designed for -40 Fahrenheit temperatures and 150 mph winds!
The one-lane tunnel must be shared by cars and trains traveling in both directions, and it usually needs to be aired out in between trips (with jet turbine ventilation, another first!). This unique design that enables a single lane of traffic to travel directly over the railroad track saved tens of millions of dollars over the cost of constructing a new tunnel.
Arrive at least 10 minutes prior to tunnel opening. Arriving earlier isn’t a waste; park in line, then get out of your car and soak in the scenery. Give yourself another 20 – 30 minutes to get through the tunnel. The drive is only 10 minutes, but the opening can be delayed, or there can be a line before you enter.
Check out https://dot.alaska.gov/creg/whittiertunnel/schedule.shtml for the updated schedule directly from the DOT website
Making a Cruise Departure?
Allow a minimum of one hour to drive from Anchorage to Bear Valley, the tunnel terminus. 1.5 hours is recommended in summer