The Dalton closes completely Tuesday morning for culvert work

The Dalton Highway closes completely Tuesday morning for about five hours, and there's no way around it.

Crews are replacing a culvert at the bottom of the 5-Mile grade, between mile markers 3 and 6. All lanes shut in both directions from 7 am until roughly noon — though the state's own listing gives a planned end time of 12:30 pm in one place and noon in another, so plan for the later one. After that, one lane opens under flagger control at 15 mph until the work wraps around 3 pm.

That matters more on the Dalton than most roads. It runs 414 miles from the Elliott Highway to Deadhorse with no alternate route, and it carries a higher share of truck traffic than any road in Alaska — more than 80 percent near Prudhoe Bay.

Two more work zones are active further north: daily flagging from 6 am to 6 pm through Sept. 30 between mile markers 279 and 394 for utility work over the Alyeska fuel gas line, and single-lane traffic with round-the-clock flagging at Milepost 315.5, where permanent repairs started this month.

Conditions are posted at 511.alaska.gov.