Researchers determine escape route travel times for firefighters

Granite Mountain Hotshots hike to the fire, June 30, 2013
Granite Mountain Hotshots hike to the Yarnell Hill Fire, the morning of June 30, 2013. Photo by Joy Collura.

When crews of wildland firefighters in a remote area have to quickly move to a safer location due to an approaching flaming front, they hike on what they call an escape route to get to a safety zone where they can be out of danger without having to deploy their fire shelters. An average of 11 firefighters die each year while fighting fire. Of these deaths, about 44 percent are caused by entrapment or burnover events.

A key to moving to a safety zone is the travel time. Underestimating the required time can be fatal, in the worst of circumstances. That may or may not have been one of the many factors involved in the deaths of 19 firefighters on the 2013 Yarnell Hill Fire in Arizona.

Firefighters know how long it takes them to hike the three miles within less than 45 minutes while carrying 45 pounds as required by the Pack Test, or Work Capacity Test. From that it’s pretty easy to calculate their miles per hour. But that is on flat ground, a situation that is not always the case when escaping from a wildfire. Throw in steep uphill or downhill slopes, and the times will increase.

Previous research on the subject includes:

A new study uses a different database for the speed at which fire crews can hike. It is titled, “Modeling Wildland Firefighter Travel Rates by Terrain Slope: Results from GPS-Tracking of Type 1 Crew Movement.” (download, 2.3 Mb)

As the name implies, instead of using public crowd-sourced hiking speed data, the researchers issued GPS units to nine Type 1 Interagency Hotshot Crews in the Spring of 2019. Nine of the 11 participating IHCs received seven GPS units each, and the other two received 20 GPS units each. In addition to the GPS units, crews were provided with data collection sheets and armbands to carry the GPS units.

Using data collected by firefighters — a uniquely physically fit population that usually carries heavy loads while moving —  provides a set of robust, adjustable travel rate models built from instantaneous travel rate data that can be applied in a variety of contexts.

The data was collected while on training hikes. Rather than rely on GPS for elevation, which is not always accurate, only locations having the more accurate lidar data were used.

The tables below are from the research paper.

Results -- travel times by slope

 

Demographics of the Type 1 crews.
Demographics of the Type 1 crews.

Here is an excerpt from the paper:

“The effects of the slope on the instantaneous travel rate were assessed by three models generated using non-linear quantile regression, representing low (bottom third), moderate (middle third), and high (upper third) rates of travel, which were validated using k-fold cross-validation. The models peak at about -3o (downhill) slope, similar to previous slope-dependent travel rate functions. The moderate firefighter travel rate model mostly predicts faster movement than previous slope-dependent travel rate functions, suggesting that firefighters generally move faster than non-firefighting personnel while hiking. Steepness was also found to have a smaller effect on firefighter travel rates than previously predicted. The travel rate functions produced by this study provide guidelines for firefighter escape route travel rates and allow for more accurate and flexible wildland firefighting safety planning.”


The authors of the paper are, Patrick R. Sullivan, Michael J. Campbell, Philip E. Dennison, Simon C. Brewer, and Bret W. Butler.

Typos, let us know HERE, and specify which article. Please keep in mind our commenting ground rules before you post a comment.

Author: Bill Gabbert

After working full time in wildland fire for 33 years, he continues to learn, and strives to be a Student of Fire.

16 thoughts on “Researchers determine escape route travel times for firefighters”

  1. Great read. The one thing that sticks out to me tho is those tables are great for hotshots. The slowest times are still likely faster than the non hotshot folks who often make up a majority of personnel on a larger incident so the that should be considered…. Men and ladies of the Jumpbros community can take exception to this

    1. I agree 100 % – i hate ‘empirical formulas’ we teach it and then it becomes this
      ‘Standard’ which in almost every case in wildland environments it really is the exception rather than the rule …. yet its not taught that way!
      I still instruct with the intent of driving these kinds of answers back down to the squad boss and up thru Div Sup training to reenforce – have sound SA and KNOW your crews abilities and exhaustion rate – guidelines are nice – but pragmatic head on a swivel and good fireline awareness is where i wish all to really be at ! Always good to have new data sets – lets just not make wildland firefighting about cook book applications- many a ole wise FF is that way by being always on their game!
      J

  2. A lot of variables, some considered, some not thought of, perhaps, and perhaps others left out?

    Being on a hike instead of running for your life may lack a certain amount of relevance to the real world.

    Strategies that place people in marginal situations may be worth further consideration.

  3. Coming from a type 1 crew, the majority of our escape routes aren’t more than 30 min away…Every now and then they are.

    We keep close tabs on the performance of the crew members on the day to day and try our best to time it off the slowest person and then double that time to add in a buffer.

    I think having your escape route cut off is one of the larger issues and knowing where to go if that happens is critical…I would wager that that happens more often than we might think or know.

    We won’t always have one foot in the black and if we’re burning, what we lit might not be suitable even after cooling off a bit – think snags…ya you use and we have but it sure as hell isnt my go to.

    BTW – if a dozer pushes out what the heqb determines as a suitable safety zone for ‘x’ amount of people – don’t park in it!

  4. It needs to be rocket science if common sense isn’t working. Hand-built lines may work in big-tree forests, but not in brush. Putting crews, especially not-so-well-trained crews, even on the flanks of a big fire, much less the front, is best avoided.

  5. All this talk about “hiking away from danger” and nothing about picking an experienced fire fighter for lookout duties and having the LO move to alternate location if he/she feels threatened. NEVER pick someone for this responsibility who is not experienced in fire behavior.
    This is paramount to keeping crews as safe as possible while on the line; along with good coms.

  6. A quote from Paul Gleason, “realize the importance of being a student of fire.” If you have never heard of Mr. Gleason I would encourage you to look him up on the internet. The wildfire lessons learned center has a publication called “Two More Chains” that put together a great article about what it means to be a student of fire. Cheers

  7. “The worst kinda ignerance ain’t so much not knowin’ as ’tis knowin’ so much that ain’t so.” –paraphrased from Josh Billings

    The higher one gets on the pile of CERTAINTY, the more likely one’s screw-ups are to get bigger and bigger. Fire is one of those highly complex phenomena that defies AUTHORITY. One always runs that risk when assuming authority. The distinction between being a STUDENT of fire and an AUTHORITY on it is CRUCIAL.

  8. Well put Wayne…
    Fire is a fluid working environment that demands one to continually re-examine your assumptions and expectations.
    The amount of time it takes to get to safety is only 1/2 of the equation..it’s pulling the trigger to get on the go that can either bite you or help you.
    Although not a ground based scenario…I found waiting too long to wind down aviation operations can put your folks(in this case flight crews) in harms way as well..
    And no more so than right in Bills back yard….where hazardous weather in all quadrants can build faster than you would expect…and your safety zone is terra firma 30 minutes out…or even further

    1. Even though I’m just a SEL pilot (now clipped and have to sell my STOL aircraft, a Just Highlander and a Zenith CH750), I can understand how true that might be. In CAVU, I’ve been hit with 1500fpm red and green air in the northern Sierra, CAT in the Owens Valley, and damned near went down in the Coldwater River.

      On the Sloat fire (ca 1960?) a TBM had the smoke shift on him and went in before he could get out. There’s a lot to juggle regardless of the type of ops, and once the fire gets (or has the potential to get) big enough to overwhelm suppression force capabilities, I would resist the peer (and overhead) pressure to put crews into remote locations to build lines. Let it burn to a better defensive position and spend the resources killing spot and structure fires. Maybe we need a hornet’s nest of grossly overpowered smaller tankers as highly maneuverable strong-airframe aerobatic-class mini-tankers that have enough power to climb in red air, with and without the load. There should be no shame in dumping the load early and getting THOT.

      Crew fatigue is an oft-forgotten factor, and cojones do not boost stamina, only bragging rights and hangar-flying (yet both valuable learning exercises). But above all, the fact that not being influenced by “reality-show” demands, TV News, or other political pressure is pressure in itself–a trap in which it is damned easy to be snared in. THAT’S the kind of BOLDNESS we need. I’ve seen fire bosses actually foaming at the mouth in anticipation of hitting a big fire who would/might be firebugs. And if you get demoted or fired, get a lawyer and “screw your courage to the sticking-place, and you’ll not fail.” “It’s a chancey job, and a little lonely.”

  9. Thanks for posting on this important, often overlooked, issue.

    Escape Routes are the paths WFs/ FFs take from unsafe present locations to safer ones; it is the most elusive safety prong due to its ever-changing status. A recent WF study found key portions of entrapment potential lies in human factors, prior WF entrapment investigations have similar reviews and proposals, weak entrapment investigation process and reporting systems, and a likely sizable under-reporting of entrapments (Jolly, M., Butler, B., Page, W., Freeborn, P.: (2019) An Assessment of Research Needs Related to Wildland Firefighter Safety. JFSP #18-S-011).

    The GMHS skillfully pursued a true Escape Route to get to a Safety Zone, then perverted that term, left their viable S/Z, and fatally hiked downhill in chimneys /chutes of unburned chaparral. Why?

    However, for whatever reason, the GMHS, on the TAC channel, they then perverted that prong of LCES once they abandoned their Safety Zone and traveled down their “predetermined route” and upon being burned over, that their “escape route has been cut off …”

  10. I don’t see the path the Foreman determined the GMHS would take, as an “escape” path. For those of us who have been there (in that kind of situation), we never go down a draw into unburned brush. Their escape route was back up the ridge and into the burned over area. Their alternative course to get to the “ranch property” was a ridge to the north and the long way around to the ranch.

  11. Ted, I couldn’t agree more with your comment regarding lookouts…it’s a serious duty and not one to be given to someone inexperienced or to someone not feeling well….if you’re sick stay at the rigs. The lookout MUST have their own escape route and safety zone..you cannot always rely on being picked up in a UTV by a fellow crewmember..or Sup of another crew.
    Calculating the rate of spread for a fire is a critical skill that all lookouts must know – too often inexperienced lookouts are not setting appropriate triggers while taking into account the rate of spread…this is a massive mistake.
    Thanks for this discussion.

Leave a Reply

Your email address will not be published. Required fields are marked *