Ballenxj wrote:
Interesting that they call it a highway, yet recommend not exceeding 35 mph? Denali Highway
Welcome to Alaska. :R
There's a frequently used unofficial motto ... "We don't care how they do it Outside!" (In this case, 'Outside' is defined as 'anywhere that's not Alaska.'
I think the state runs a grader over the Denali Highway maybe once a year and possibly as infrequently as every three or four years. Given frost heaves occur every year, 35 mph -- or slower -- is prudent unless you enjoy feeling your vehicle going airborne.
Despite more regular maintenance, there are sections of the Haul Road that are best described as 'unimproved roadway.' (And that may be stretching things a bit.)
The main road between Fairbanks and where we live -- Chena Hot Springs Road (CHSR) -- is sometimes called the Chena Hot Springs Rollercoaster. It's paved so fixing frost heaves and melting permafrost pockets is more difficult and expensive.
All roads expose ground with permafrost pockets to sunlight, causing them to melt and collapse. Pavement collects more heat from the sun, causing the pockets to melt faster and more dramatically.
Common practice is to dig down 8-10 feet and lay down polystyrene insulation before building the roadway back up. When they rebuilt a section of CHSR, they drill holes looking for permafrost. Turns out they didn't drill deep enough. After a three-day weekend, they ran a scraper into the 12 foot deep trench they'd been working on. It promptly sank into melting permafrost and rolled over onto its side. It took several D11 bulldozers to drag it back out of the mess.
