OK, then you point out on a map where you would go in your 172 after you enter this valley.
I'm afraid with my computer lack of technical expertise, I couldn't even post the map, let alone figure out how to point out terrain on it. Who needs to enter the valley? One can go around; that's really the point isn't it? There are a number of other better routes across the state, as has been pointed out numerous times, and one is best advised to take experience along, especially the first time. This has also been pointed out again and again.
Skyhawk drivers can look at the options and altitudes and decide if they think Doug's advice is sound. Look around on it. The road goes into the tunnel. You were following it. Probably upwind. Groundspeed is slow. Where you want to go?
Some of you are so busy trying to find fault, or perhaps lack the experience to make the decision yourselves (who knows?), you missed the point. At no time did I ever suggest one should pick a road and stay directly over it at all times, and only an idiot would follow the road to the tunnel in a suicidal bid to maintain the highway centerline.
Roadmaps provide some measure of guidance that is usefulwhen planning a trip. A roadmap doesn't mean one must stay atop the road for any or all of the trip. It's a starting point. It covers known points. Roads tend to follow drainages, and provide some useful insight into the routing that can add to one's use of sectionals and other charts.
And, how does one cross that pass at a 45 degree angle for a quick turn-out if downdrafts higher that the climb performance of the aircraft are encountered?
A better practice is to parallel the ridge, close, and give a greater out with decreasing performance; a quick turn across the ridge and down works better than a 45 degree approach, especially when flying in the mountains close to one's performance margins.
There are two problems with the I-70 route using Loveland Pass for the OP.
1. The road is not conducive to landing anywhere.
2. There are no "outs"
3. A C172 does not have the HP to get out of trouble
You should never fly with the idea that you have horsepower to get you out of trouble. That's where planning comes into play. Most of my flying in mountain areas revolves around using orographic lift for performance. Learn to fly a sailplane and you'll gain a greater appreciation for operating a lower performance aircraft in the mountains. Mountain flying isn't about outperforming the hills. You won't do that in a light airplane. In fact, you won't do that in most aircraft. The terrain will nearly always outclimb you. You can outplan it, you can outfly it, but you can't match it for power or performance.
I certainly never suggested that the original poster venture out on his own to challenge the hills. I grew up flying light airplanes in the mountains, and it doesn't concern me a great deal. One needs to use the mountains to one's advantage. One needs to have an understanding of flying in the mountains. One shouldn't simply strike out on one's own and guess, or try to teach one's self.
I've spent a lot of time flying aircraft loaded down heavily with retardant that can't do better than 100 fpm climb on a really good day, into mountain areas. I survived doing this by using the terrain to my advantage, always having an escape, usually several, and by very thorough planning and a willingness to say "no." Simply planning which side of the valley to fly often makes the difference between positive climb performance and negative performance.
Yes, the wind blows up there. Yes, there's a lot of descending air. There's also a lot of rising air. Yes, the airplane will be capable of being flown higher in the mountains than it will go in the flatlands, because if one knows where to find lift, there's a lot of extra performance available to use.
At a mountain drop zone, I regularly flew loads of jumpers to 16,000 in 182's, all day long. I flew loads of gas cans, river runners, and cargo and people in and out of the Grand Canyon, in 172's, landing down in canyons and canyon airstrips, and climbing out of canyon areas over mountains all day long, when the airplane didn't have the performance to get there by itself. Flying the terrain, using the terrain, and especially orographic lifting, made the difference, and was a routine part of making those flights. It's all about using the terrain and some common sense.
Anyone ever watch the Cessna 150 towing gliders out of Telluride? They tow gliders there all day long too, and they do it quite well. Mountains are there to be respected, but the world doesn't end where the mountains begin, and neither does flying. There's a great deal of wealth in enjoyment, experience, and for those who so desire, adventure to be had flying in the mountains. The mountains aren't forgiving, but then not much in aviation is.
As for using the roads, yes, they do make useful emergency landing sites. Anyone here ever make a forced landing in the mountains following an engine failure? I have.
Based on your resume in hours, familiarity with Colorado geography, type of aircraft and type of flights, you have considerably more experience than the OP who admits to being low-time and a novice. You have years of terrain knowledge, of weather, thermals, etc. Getting out of trouble is instinctive for you because you've probably repeatedly dealt with the issues over the years.
There's no question about that, and I recognize the disparity. I'm not telling anyone to blast off willy nilly and fly themselves into a mountainside, and I certainly never told anyone to hover over the highway in a desperate bid to get through the tunnel. I did strongly recommend that the original poster get an instructor or a trusted friend who knows the terrain, knows mountains, knows his airplane, knows the weather, knows the capabilities and especially the limitations, and who can make the trip an educational and safe one, to accompany him and teach him about flying in that country. I also encouraged him to use varioius resources at hand (including road maps) to help determine a good route through to GJT.
The original poster may want to make various forrays into hilly areas over time. Not all in one day. Make a day trip here or there. An eventual trip to leadville has been all but a right of passage for many, if only to say they'd done it, bought the tee shirt. He or she may decide to drive on the appointed day. He or she may go north or south. All valid decisions, valid choices. I've driven that route many times, and flown it many times. It's beautiful country. It could easily become one's grave if one makes poor choices, and it could also become a great learning experience and a valued memory. One must approach it responsibly.
Many times I've flown general aviation airplanes into or through terrain I couldn't climb over on power alone, and I've done it on the merits of flying the terrain, tucking up to ridges where I found lift, and flying the proper sideof the valley, by knowing the winds, knowing where I could expect lift and where I could expect not to have it, and always leaving myself generous outs, as should everyone that flies in the mountains.
Most definitely one shouldn't simply blast over the hills without planning, thinking about it, preparing, and getting adequate training. One ought not do it the first time out. Can one do it? Absolutely, and one can do it safely. Is it for everyone? Absolutely not. Can it be done by anyone, with all of the aforementioned in preparation? Yes. Should it be done alone? Not necessarily; that depends on the person, the aircraft, the day, the weather, the circumstance, the preparation, and so on. Each must decide.
I suspect the original poster is smart enough to recognize all this, just as the original poster is smart enough to know not to tackle it straight across by himself the first time out. I even give the original poster enough credit not to be idiotic enough to think of trying to fly into the hillside while hovering over the road centerline by the tunnel. Nobody is going to try that, especially based on the merits of an internet discussion board.
The trip is doable, and it's majestic country. Nobody puts a gun to your head and makes you fly it, but for those who choose to do so it's not only possible but enjoyable, challenging, and memorable.