“The Half Dome Cables Study” Part 4

Half  Dome – Yosemite Musing
     Today I’ll wrap up the study of the Half Dome cables report. By the way, you can read all 102 pages by clicking <HERE>. As we plow deeper into the report, the study showed that mean ascent times are relatively constant around 24 to 30 minutes, across the hours of the day. They found 20 minutes was the mean for descending the cables.  This was a real surprise. When they are empty I can get up in 10 minutes – my personal record is 7 ½, so 24 -30 minutes is nothing to crow about.  The next morsel I found is that nearly all visitors who participated in the Half Dome Trail hiking route survey reported they did not have to wait in a line at the base of the cables. Of those visitors who did report waiting in queue, most (98%) reported having to wait 15 minutes or less. Hmmmm, what about those crowds we know about? 15 minutes…gee, I wait longer getting my pizza at Curry!  Here’s a photo I took at 1pm on June 23, 2007.  Yikes. 

Start of cables is about 1/4 from bottom of photo.

When I got down I asked the people just getting on the cables how long they had been waiting – 45 minutes just to get to the head of the line.  There appears to be a bit of discrepancy between the study and what most of us experience. 20-149
    The next topic was an analysis of people who go up/down outside the cables. I’m curious why this was done, as it’s not one of the stated objectives. In a sample of 543, 16 admitted to such. Why? They responded that they went outside: 1) to avoid being delayed by crowds; 2) they thought it would be safer; 3) they thought it would be more fun. Before I wrote my current book I asked the Wilderness Rangers their opinion of going outside. The reply was that the granite is actually better outside since it didn’t have 90 years of wear on it. They had no problem. I do not recommend that people go outside and the park does not “recommend” it either. But it is not prohibited. The only published rule (until the permit process) was that you could not camp on the top. That ended in 1992 due primarily to “human impact.” (Poo)  It took me about 8 trips to get the courage to go outside. I found that using one cable in a rappelling manner was a way better use of my stronger muscles. I can go at my pace and I personally feel very secure with good boots and rubberized gloves.
     In the same survey just 5% of respondents reported that they perceived crowding and the number of people on the cables to be a safety issue that needs to be addressed.  The survey also presented many “improvement scenarios” that the respondent could express an opinion. Increased signage received the greatest level of support from visitors. 57% of respondents reported that they support increasing the amount of signage concerning hazards of the Half Dome hike and 59% support increasing the amount of signage concerning mileage. No other management actions were supported by a majority of visitors, and only a few received support from 25% or more respondents they were:1) providing rangers to enforce Leave No Trace principles (42% support and 29% oppose); 2) implementing a visitor education program concerning the Half Dome hike (35% support and 36% oppose); and 3) implementing a permit system to limit use of the Half Dome Trail and cables route (27% support and 46% oppose). Management actions that received the least support from respondents included: 1) requiring visitors to start their hike to Half Dome before 7:00 AM (23% support and 53% oppose); 2) requiring visitors to undergo an orientation emphasizing safety considerations associated with the Half Dome hike (21% support and 55% oppose); 3) limiting the extent to which the NPS promotes the Half Dome hike (18% support and 49% oppose); 4) requiring visitors to use safety equipment on the Half Dome hike (15% support and 64% oppose); and 5) charging a fee.
     Lastly, here’s some data just for giggles. 37% of the hikers interviewed had a masters degrees,   58% were under 34 years old, 70% were from California and of the foreign visitors contacted, 26% were from the UK, 18% were Dutch and 15% were German. OK, so that’s my analysis. I will leave the interpretation of the study and the resultant permit plan up to you. 
Unrelated thought worth quoting: “The gross heathenism of civilization has generally destroyed nature, and poetry, and all that is spiritual. “ – John Muir
*Mr. Half Dome – Rick Deutsch – www.HikeHalfDome.com


4 Responses to ““The Half Dome Cables Study” Part 4”

  1. Dave Messina Says:

    Has anyone thought of a SIMPLE solution, by adding one more cable line. That way there will be one side for ascending and one side descending.

  2. Larry Says:

    Hey Rick – thanks as always for your great work on this site.
    On wait-time means or medians: the law of averages makes something between 20 and 30 minutes credible, even if some waits on busy perfect-weather days edge towards an hour. Quibble with how meaningful the posited point of central tendency is relative to the actual underlying distribution. The Central Limit Theorem is pretty robust; it clings to the statistical cables pretty securely even when you throw one or two outliers at it. What you pose with your countervailing evidence is, really, the need to identify the prevalence of glut-queue conditions each season. The study does help us see the underlying distribution a bit, and we probably could get our hands on the raw data. “There appears to be a bit of discrepancy between the study and what most of us experience” implies your sample size is unbiased and as large as theirs … not likely. Takeaway: if the distribution of wait-times is flat enough, a mean of, say, just 15 minutes may still leave a substantial probability that folks will wait 45 minutes or more. The techniques used in such travel-time studies have been around for a very long time, and are continually vetted for rigor and precision; anecdotal gripes about accuracy probably should be set aside.

    • mrhalfdome Says:


      Valid perspective. You sound like you know your “stat.”

      The verbal comments recorded (a very small sample) was that they did not have to wait at all. For a team to be at the cables for a month and have such a tiny sample size seemed odd to me. The 15 minute mean time means that half of the “waiters” had to wait more than 15 minutes and half had to wait less. 98% reported not having to wait more than 15 minutes. My universe of samples is just the few times a summer I go up the cables. I consistently see a line forming a bit after 11. But then, I didn’t do the NPS study. I admit I am a giant skeptic when it comes to surveys and polls – judge the last presidential election. According to the “New Eatery” Theorum of 1955, if a restaurant is crowded and you really want to eat there – next time arrive earlier. I hope you join in the NEPA (National Environmental Policy Act ) process the park will be starting “this spring”. An environmental assessment will be key to the long-term cables solution. We need all the good heads on this one.

  3. Sandra Says:

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    i will visit this web more often and read about your post,
    i like ur topic specially about
    “The Half Dome Cables Study” Part 4


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