I’d like to tell you a long story about airplanes to help describe the road from Cusco to Quillabamba and Machu Picchu.
Two important concepts in airplane design are stability and control sensitivity. There are 2 kinds of stability: static and dynamic. Static stability means when a pilot lets go of the controls during normal stabilized flight, that the airplane will maintain its attitude – so the pilot can grab a map or cup of coffee and the airplane will continue on its merry way. Dynamic stability means when an airplane is disturbed from stabilized flight that it will eventually return back to its stabilized flight path. For example when a pilot yanks on the controls to avoid hitting a bird, an airplane with good dynamic stability will enter a slowly decreasing porpoising motion and eventually return to its steady state flight path. Finally control sensitivity means how quickly the airplane responds to the pilot’s control inputs and how much force the pilot needs to exert on the controls to fly the airplane.
In the early days of aviation these concepts were not well understood, for example, in a Ford Tri-Motor you could slam the controls completely back and forth on approach but the resulting airplane movement was almost indiscernible, the controls were very ineffective at slower speeds. I never flew a Ford Tri-Motor but I knew a guy who did, he flew for an outfit that smuggled liquor in Tri-Motors during prohibition. The Piper J3 Cub was one of the first mass produced airplanes that had these concepts figured out, it’s the nicest flying little plane. Of course airliners nowadays are all controlled by computers, their flying characteristics are programmed in, not achieved only by aerodynamics.
At the end of the day, there is an acceptable range of stability and control sensitivity. For example, a training airplane typically has less stability because the designers want to force the student pilot to be attentive at all times. In another example, I flew with a pilot who liked to barrel roll fully loaded Convair 240s and Gulfstream G1s but he swore to never try the same in a Convair 340 or 440, its roll rate is too slow.
In this acceptable range of stability and control sensitivity, if an airplane is not very stable but has sensitive controls, a pilot might say it’s a “touchy” or “squirrelly” airplane.
Legend has it that one of the early pilots to fly the Pitts Special was a bit shook up after landing by the airplane’s power and handling, telling Curtis Pitts “that’s one squirrelly airplane you built!” To which Curtis Pitts famously responded “I’ve never known a squirrelly airplane but I’ve met a lot of squirrelly pilots!”
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I drove the road from Cusco to Quillabamba for the first time last week, Quillabamba is the closest town to Cusco on the edge of the jungle, it’s nice to take the kids there for a swim in the pool. The road to Quillabamba is the same road tourists take to go to “Machu Picchu by car” as you see advertised everywhere in Cusco, I believe it’s less expensive than taking the train. The road goes via Ollantaytambo up near Nevado Veronica at an elevation of just over 4,300 meters (about 14,000 feet) and then back down to 1,100 meters (about 3,500 feet) by the time you reach Santa Maria. From Santa Maria you can continue on to Quillabamba or take the detour to Santa Teresa, then via the Hydro-Electrica to Machu Picchu.
Locals say it’s a dangerous road. If you want my advice, take the train to Machu Picchu. I’ve never met a dangerous road but I’ve sure met a lot of dangerous drivers, and the road to Quillabamba is very unforgiving of dangerous drivers.
Life in Peru 
I didn’t think the road to Quillabamba was all that bad, of course we did not run across any dangerous drivers either. We visited last month and while there did find a dangerous trail, I actually fell about 2 stories while hiking to some waterfalls, and separated my collarbone from the shoulder. We have never driven to Santa Teresa, but from what we have heard from some of the guests that have done the road route, it is the section between Santa Maria and Santa Teresa that is the worst, single lane for most of it and windy, not to mention it is mostly dirt and subject to washouts or slides during the rainy season.
Have you made the drive to the Lares hot springs yet? Beautiful drive and a more difficult road.
Ouch, I hate to hear you got hurt.
We drove to Quillabamba during the “winter vacation” so I suppose the road was busier than usual, all the Cusquenians escaping the city to some warmer weather for the winter break. I haven’t been to Lares yet, I thought I heard that road is paved now? When did you guys last go to Lares? We just have a smaller car so I try not to go off-roading too much!
Yes I could see how increased traffic could make it a bit worse.
Aside from a few short sections, mainly close to Calca and just before the hot springs, the road is paved all the way. If you guys decide to make a trip some weekend let me know, if we are not busy maybe we could all go together, we love it there and the drive is amazing. We have been a dozen times with the most recent trip being about 2 weeks ago. We generally like to make it an overnight trip as there are rooms right there at the hot springs and it is more relaxing to spend the night.
I survived the road to Qillabamba with my husband and children in the summer of 2003. I’d had some trepidation about driving through the mountains in a third world country, but our innkeepers assured me the road was paved and smooth and very safe. We left Ollantaytambo in late afternoon. The road was mostly dirt then, and while spectacular with immediate, drop-dead views, very poorly maintained, no shoulders. By the first miles, which gain elevation quickly, I could tell this was going to be a treacherous trip — in the dark. At the top of the first high pass it was snowing, and the dirt road slippery. That there is a tiny, candle-lit, dirt floor chapel there, for pit stops to pray for a safe journey over the Andes, only added to my building fear. Lucio, our guide and driver was a wonderful Peruvian guy, but macho and aggressive to my American sensibilities, who had to pass any vehicle that was in front of us on the road, even if the road was crap, the sides looked unstable above the thousands of feet of drop off, even if there was a hairpin curve coming up, and a tour bus might be barreling along coming from the other direction. The busses, and trucks carrying produce and supplies and workers all seemed to be going way too fast for the conditions; I had to keep reminding myself I was an ill-traveled, unadventurous American accustomed to the safest roads in the world. The road kept climbing and curving this way and that with hair-raising views down the increasing, thousand foot drops. On the way east, you are driving on the inside land, but we were often on the outside (wrong) lane when our driver felt compelled to pass or avoid the frequent large potholes and rocks in the road. Then you are looking out the van window directly down many thousands of feet. Long sightlines are few, and it gets narrow, too, with waterfalls and washouts at each ravine crossing. Crosses mark the places where unlucky souls have gone over the edge. It’s the first and only time I truly feared for my family’s life. I was in tears and paralyzed with fright until it felt like we were finally heading down the other side. I asked my husband to ask Lucio to slow down, but it didn’t make much difference. The latter hours of the descending journey through the jungle seemed endless in the pitch dark, but I could feel my terror loosen its grip. At times you could see we were passing high above a large brown river shining in the moonlight. Once in a while we passed through a tiny settlement with a few lights and people wanting to sell us fruit. Two or three times we inched by trucks that had broken down and were waiting for someone to stop. The driver would just be sitting helplessly by the side of the narrow road with a small fire going. (When had our van last been maintained or inspected?) For a long time it seemed possible we were just lost. Lucio would say we’d be in Quillabamba in “30 minutes” and then an hour later we were still bouncing through the darkness with no distant lights of a town or city in sight. This sequence happened about three times during the next couple of hours. Twice my husband asked Lucio if he knew where he was going. Finally we arrived in Quillabamba, too late for the festival we’d come to see, and the plan was to make the return trip by the same route the next day.