It's weird that they haven't come up with a better system other than "the tunnel changes directions every hour and shuts down at a certain hour, forcing people to sleep in their cars." In the boonies when they have to make a bridge one-way they put traffic lights at each end with radar presence sensors.
Seems like the rule is serving as an unofficial (and frankly illegal) town "drawbridge" to keep the riff-raff out.
Edit: to all the replies telling me how it couldn't possibly work because people will break the rules: which is also true of the current system? And gates are a thing, folks. So is automated enforcement?
If it's a private tunnel, nothing stops the railroad from saying "if you ignore the traffic control system, we fine you $x. If you do it again, you're barred from using the tunnel for a month and have a fine of $x*2. If you do it again, you're barred from using the tunnel permanently." Watch how fast people follow the rules.
Why is Whittier so important to the Alaska Railroad?
From an economic and geographic standpoint, Whittier represents the Alaska Railroad's only viable freight interchange point for its barge service connecting Alaska with the lower 48 states and Canada. Seward and Anchorage are not viable port alternatives for barge interline service. Anchorage is not free of ice year-round and Seward requires traveling over a mountain pass at a 3% grade (it would take six locomotives to haul a heavy load from Seward versus two from Whittier). Whittier is a year-round, ice-free, deep-water port. It is located only 50 miles from Anchorage and has slight grades for trains and engines. For these reasons, all the Alaska Railroad's railcars, locomotives, and rail-borne freight must enter and depart via Whittier.
because the tunnel was built for trains, not cars. The tunnel was built by and for the military back when the base was important; there isn't enough reason to spend the money to expand the tunnel now.
You’re underestimating how long the tunnel is, how many vehicles are waiting to go through, and how unwilling to follow rules people are. When I was waiting to drive through it last summer some guy decided he was tired of waiting and tried to drive around the line and into oncoming traffic. The railroad police had to chase after him and stop him before he shut the whole tunnel down.
It's a really, really long tunnel. GP's estimate of 5 minutes travel time sounds reasonably accurate. If someone ignored the light and went down it while someone was coming in the other direction, getting traffic unsnarled could be a headache. Even more so if there was a collision.
Seems like the rule is serving as an unofficial (and frankly illegal) town "drawbridge" to keep the riff-raff out.
Edit: to all the replies telling me how it couldn't possibly work because people will break the rules: which is also true of the current system? And gates are a thing, folks. So is automated enforcement?
If it's a private tunnel, nothing stops the railroad from saying "if you ignore the traffic control system, we fine you $x. If you do it again, you're barred from using the tunnel for a month and have a fine of $x*2. If you do it again, you're barred from using the tunnel permanently." Watch how fast people follow the rules.