With Six You Get Speed Run
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With a full complement of 6 drivers, it will be possible to drive straight through. Here on some tips on making such a drive safely and sanely. Perhaps the most important point is that you must have at least two people awake at all times, so that someone is available to keep an eye on the road and the driver. 24 hours should be about right if you just do the straight shot out I-80 to western Nebraska, I-76 to Denver and I-70 west from there. Your final drive into Aspen presents a dilemma and choice. The short route is CO-91/US-24 south from Wheeler Junction and CO-82 west, but if you're all tired, it's dark, or the weather is uncooperative, then you should seriously consider continuing west on I-70 to Glenwood Springs and backtrack on CO-82 rather than trying to cross the Continental Divide by way of Independence Pass.
AZBuck