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Cited by 20Occupational Health and PerformanceFire dynamics and safety researchFire effects on ecosystems

The DOI matches its Crossref record; 32 of the 34 references it cites were found in a registry or an index; 2 of the 25 sources its claims cite were checked for support.

Modeling Wildland Firefighter Travel Rates by Terrain Slope: Results from GPS-Tracking of Type 1 Crew Movement

Open access
Sullivan, Patrick R., Campbell, Michael J., Dennison, Philip E., Brewer, Simon C., Butler, Bret W.·2020·Fire
DOI 10.3390/fire3030052
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Abstract

Escape routes keep firefighters safe by providing efficient evacuation pathways from the fire line to safety zones. Effectively utilizing escape routes requires a precise understanding of how much time it will take firefighters to traverse them. To improve this understanding, we collected GPS-tracked travel rate data from US Interagency Hotshot “Type 1” Crews during training in 2019. Firefighters were tracked while hiking, carrying standard loads (e.g., packs, tools, etc.) along trails with a precisely-measured terrain slope derived from airborne lidar. 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 a −3° (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.

Overview

AI snapshot

Written from the paper’s full text.

TL;DR

This study used GPS tracking of US Interagency Hotshot Type 1 crews during 2019 training hikes to model wildland firefighter travel rates as a function of terrain slope. It produced low, moderate, and high travel-rate functions via non-linear quantile regression, with the moderate model performing best and generally predicting faster movement than prior pedestrian functions.

Key findings

  • The three Lorentz functions peaked at slightly downhill slopes: low at 0.974 m/s on −2.8°, moderate at 1.404 m/s on −2.9°, and high at 1.699 m/s on −2.6°.
  • The moderate travel-rate model performed best in 5-fold cross-validation: MAE = 0.081 m/s, R² = 0.86, bias = 0.002 m/s. The low model had MAE = 0.172 m/s, R² = 0.39, bias = 0.046 m/s; the high model had MAE = 0.152 m/s, R² = 0.57, bias = −0.047 m/s.
  • The moderate firefighter function mostly predicted faster travel than previous slope-dependent functions, while steepness had a smaller effect on firefighter travel rates than previously predicted.
  • Travel-time guidelines from the moderate function: about 12 min for 1 km, adding about 3 min for a downhill 15° slope and about 6 min for an uphill 15° slope; the low function predicted about 17 min for 1 km, adding about 5 min downhill and about 9 min uphill.

Methods

  • GPS units recorded at 1-s intervals for Type 1 Interagency Hotshot Crew firefighters during 2019 training hikes; 85 firefighters carried units, but the final dataset included 21 firefighters (1 female, 20 male) from 3 crews, 108,600 records, 44 hikes, 9 trails, and 209 km, with elevations from 263 to 2418 m.
  • GPS points were snapped to digitized trails, elevations were extracted from 25-cm lidar-derived digital terrain models, and slope, 3D distance, and instantaneous travel rate were calculated; extensive filtering removed points >10 m from trails, 0 m/s rates, >7 m/s rates, slopes beyond ±45°, stationary periods, short activities, and qualitatively atypical activities.
  • The Lorentz function was fit with non-linear quantile regression in R for the 16.7th, 50th, and 83.3rd percentiles, representing low, moderate, and high travel-rate tertiles; k-fold cross-validation with k-means clustering was used to avoid pseudo-replication, and MAE, R², and bias were averaged.

Limitations

  • Stated: load effects were not explicitly modeled, and the functions assume load carriage; if firefighters drop packs and run during emergency evacuation, the functions no longer apply, and if crews become separated, group-travel assumptions fail.
  • Stated: data were collected before fire season began, and future research should examine fatigue, number of days fighting fire, temperature, time of day, trail surface conditions, activity length, panic, and effort.
  • Evident: the final sample was small and narrow—21 firefighters from 3 Type 1 crews, with only one female—and lidar availability eliminated training areas used by 5 crews; qualitative filtering removed atypical activities, and the low travel-rate model had relatively poor explanatory power (R² = 0.39).

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.3390/fire3030052

Cites

32 of 32 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Verification

Claims the paper makes

2 of 25 cited sources checked · 2 supported · 0 flagged

  • Interpretationreasoning

    Type 1 firefighters may hike faster on average than the general population and military cadets.

    “Since the moderate function predicts travel rates greater than recent pedestrian models from Campbell et al. [29] and Irmischer and Clarke [35], Type 1 firefighters may hike faster on average than the general population and military cadets.”
    Quote in the paperNot a substantial claim1 of 2 sources checked
    • cites [29] Campbell, 2019, Using crowdsourced fitness tracker data to model the relationship between slope and travel rates, Appl. Geogr. source
    • cites [35] Irmischer, 2018, Measuring and modeling the speed of human navigation, Cartogr. Geogr. Inf. Sci. source
  • Findingnone given

    All travel rate functions predict a decrease in travel rate as slope increases.

    “All travel rate functions predict a decrease in travel rate as slope increases.”
    Quote in the paperSubstantial claim
  • Findingown data

    This study modeled the effect of slope on travel rate while Type 1 firefighters hiked carrying a load.

    “This study modeled the effect of a slope on the travel rate while Type 1 firefighters hiked carrying a load.”
    Quote in the paperSubstantial claim
  • Findingown data

    All models were significantly different from the null hypothesis of a no slope-travel rate relationship.

    “Likelihood ratio tests were performed on each model and we found that all models were significantly different from the null hypothesis of a no slope-travel rate relationship.”
    Quote in the paperSubstantial claim
  • Findingcitation

    For flatter slopes, the Butler et al. recommendation is in closer agreement with the moderate travel rate function.

    “For flatter slopes, the Butler et al. [21] recommendation is in closer agreement with the moderate travel rate function.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [21] Butler, B.W., Cohen, J.D., Putnam, T., Bartlette, R.A., and Bradshaw, L.S. (2000, January 10–12). A method for evaluating the effectiveness of firefighter escape routes. Proceedings of the 4th International Wildland Fire Safety Summit, Edmonton, AB, Canada.

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim. 30
  • It may state two separate claims as one. 30

  • Probably not a substantial claim. It may be too vague to check against evidence. It may state two separate claims as one.

    Premisecitation

    Improving our understanding of how firefighters traverse various landscapes is essential for the assessment of relative egress capacity, estimation of medical evacuation time, mapping of least-cost escape routes, and knowledge of when to trigger an evacuation.

    “Improving our understanding of how firefighters traverse various landscapes is essential for the assessment of relative egress capacity [24], estimation of medical evacuation time [44], mapping of least-cost escape routes [34], and knowledge of when to trigger an evacuation [26].”
    Quote in the paperNot a substantial claim1 of 3 sources checked
    • cites [24] Campbell, M.J., Page, W.G., Dennison, P.E., and Butler, B.W. (2019). Escape Route Index: A Spatially-Explicit Measure of Wildland Firefighter Egress Capacity. Fire, 2. source
    • cites [44] Calkin, 2011, A real-time risk assessment tool supporting wildland fire decisionmaking, J. For. source

      Checked before — its earlier verdict is held back until a new check runs.

    • cites [34] Campbell, 2017, A LiDAR-based analysis of the effects of slope, vegetation density, and ground surface roughness on travel rates for wildland firefighter escape route mapping, Int. J. Wildland Fire source

  • It may state two separate claims as one.

    Findingown data

    Existing functions predict travel rates mostly higher than those predicted by the low firefighter travel rate function, but below those predicted by the moderate firefighter travel rate function.

    “A comparison reveals that these functions predict travel rates mostly higher than those predicted by the low firefighter travel rate function, but below those predicted by the moderate firefighter travel rate function (Figure 5).”
    Quote in the paperNot a substantial claim

  • It may state two separate claims as one.

    Findingown data

    On average, firefighters hike faster and more consistently across varying slopes than previous functions derived from a more general, non-firefighter population predicted.

    “These models show that, on average, firefighters hike faster and more consistently across varying slopes than previous functions derived from a more general, non-firefighter population, predicted.”
    Quote in the paperSubstantial claim

  • It may state two separate claims as one.

    Findingnone given

    Tobler's hiking function predicts much faster travel rates on low slopes and at its peak comes close to the high firefighter travel rate function.

    “An exception is Tobler's hiking function, which predicts much faster travel rates on low slopes and at its peak comes close to the high firefighter travel rate function.”
    Quote in the paperNot a substantial claim

  • It may state two separate claims as one.

    Findingown data

    The high travel rate model fell in between the others in terms of explanatory power and predictive error, with MAE = 0.152 m/s and R 2 = 0.57.

    “The high travel rate model fell in between the others in terms of explanatory power and predictive error (MAE = 0.152 m/s; R 2 = 0.57).”
    Quote in the paperNot a substantial claim

  • It may state two separate claims as one.

    Findingown data

    Among the three models, the moderate travel rate model performed the best, with a relatively low MAE (0.081 m/s) and relatively high R 2 (0.86).

    “Among the three models, the moderate travel rate model performed the best, with a relatively low MAE (0.081 m/s) and relatively high R 2 (0.86).”
    • Also stated in: § 4. Discussion · plain
      “Out of the three models produced by this study, the moderate travel rate model performed the best with an R 2 value of 0.86 and a MAE of 0.08 m/s.”
    Quote in the paperSubstantial claim

  • It may state two separate claims as one.

    Findingown data

    The width parameter b decreased from the low to the high tertile, indicating a stronger slope effect as the travel rate increased.

    “The width parameter, b, decreased from the low to the high tertile, indicating a stronger slope effect as the travel rate increased.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Firefighters did not record any sprints during data collection.
    • The authors state this as an assumption: Atypical slope-travel rate records were the result of unique training practices that do not represent normal hiking conditions or mixing running and hiking within the same activity.

  • It may state two separate claims as one.

    Findingown data

    The models peak at about a -3° (downhill) slope, similar to previous slope-dependent travel rate functions.

    “The models peak at about a -3 • (downhill) slope, similar to previous slope-dependent travel rate functions.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Firefighters did not record any sprints during data collection.
    • The authors state this as an assumption: Atypical slope-travel rate records were the result of unique training practices that do not represent normal hiking conditions or mixing running and hiking within the same activity.

  • It may state two separate claims as one.

    Findingown data

    The low travel rate function would predict 17 min for a one kilometer hike, adding approximately five minutes for a downhill 15° slope and approximately nine minutes for an uphill 15° slope.

    “The more conservative low travel rate function would predict 17 min for a one kilometer hike, adding approximately five minutes for a downhill 15° slope and approximately nine minutes for an uphill 15° slope.”
    Quote in the paperSubstantial claim

  • It may state two separate claims as one.

    Findingreasoning

    The low travel rate model featured the lowest performance of the three, with MAE = 0.172 m/s and R 2 = 0.39.

    “The low travel rate model featured the lowest performance of the three (MAE = 0.172 m/s; R 2 = 0.39), likely attributable to the abundance of near-zero travel rates across the entire range of slopes in the lower tertile.”
    Quote in the paperNot a substantial claim

  • It may state two separate claims as one.

    Findingown data

    The coefficient e was close to zero but positive for the low travel rate function and negative for the moderate and high travel rate functions.

    “Values of e, the coefficient that accounts for anisotropy in hiking rates on either side of the peak, were close to zero but positive for the low travel rate function and negative for other two functions (Table 2).”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Firefighters did not record any sprints during data collection.
    • The authors state this as an assumption: Atypical slope-travel rate records were the result of unique training practices that do not represent normal hiking conditions or mixing running and hiking within the same activity.

  • Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

    Findingown data

    The shortest recorded hike was 0.3 km, the longest hike was 12.7 km, and the average hike was 4.8 km.

    “The shortest recorded hike was 0.3 km, the longest hike was 12.7 km, and the average hike was 4.8 km.”
    Quote in the paperNot a substantial claim

  • It may state two separate claims as one.

    Findingown data

    Based on the moderate travel rate function, a firefighting crew could expect to travel one kilometer in approximately 12 min, adding approximately three minutes for a downhill 15° slope and adding approximately six minutes for an uphill 15° slope.

    “Based on the moderate travel rate function, a firefighting crew could expect to travel one kilometer in approximately 12 min, adding approximately three minutes for a downhill 15° slope and adding approximately six minutes for an uphill 15° slope.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Findingown data

    The average positional drift from the actual trail was 1.5 m.

    “The average positional drift from the actual trail was 1.5 m.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Interpretationreasoning

    The positive value of e for the low travel rate function may be due to poorer fit of the model and sparser data on the steepest slopes.

    “The positive value of e for the low travel rate function may be due to poorer fit of the model and sparser data on the steepest slopes.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Firefighters did not record any sprints during data collection.
    • The authors state this as an assumption: Atypical slope-travel rate records were the result of unique training practices that do not represent normal hiking conditions or mixing running and hiking within the same activity.

  • Probably not a substantial claim. It may be too vague to check against evidence. The paper’s conclusions may not depend on it.

    Premisecitation

    The designation of both escape routes and safety zones should also take into account hazards such as the potential for falling snags, a significant cause of firefighter fatality.

    “The designation of both escape routes and safety zones should also take into account hazards such as the potential for falling snags, a significant cause of firefighter fatality [45].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [45] Dunn, 2019, Spatial and temporal assessment of responder exposure to snag hazards in post-fire environments, For. Ecol. Manag. source

  • Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

    Study design and conductown data

    Lidar availability eliminated training areas used by 5 crews, and filtering further reduced the data such that 21 firefighters from three crews contributed data to the final dataset, which consisted of 108,600 records.

    “Lidar availability eliminated training areas used by 5 crews, and filtering further reduced the data such that 21 firefighters, one female and 20 males (Table 1), from three crews contributed data to the final dataset, which consisted of 108,600 records.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim.

    Study design and conductown data

    The models were validated using k-fold cross-validation.

    “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.”
    • Also stated in: § 2.3. Analysis · plain
      “k-fold cross-validation was utilized to assess the predictive accuracy of each model.”
    Quote in the paperSubstantial claim

  • It may state two separate claims as one.

    Interpretationreasoning

    The more models added, the more inflated the accuracy measures become, as the variance within each quantile shrinks.

    “Additionally, the more models added, the more inflated the accuracy measures become, as the variance within each quantile shrinks.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim. It may be too vague to check against evidence. The paper’s conclusions may not depend on it.

    Interpretationnone given

    These new functions can be applied in a variety of contexts, including GIS-based least-cost path modeling for escape route planning based on existing terrain conditions.

    “These new functions can be applied in a variety of contexts, including GIS-based least-cost path modeling for escape route planning based on existing terrain conditions.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim.

    Study design and conductnone given

    5-fold cross-validation was run on each model to measure the predictive accuracy of the models.

    “5-fold cross-validation was run on each model to measure the predictive accuracy of the models (Table 3, Figure 4).”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim. It may be too vague to check against evidence. The paper’s conclusions may not depend on it. It may state two separate claims as one.

    Premisecitation

    Escape routes are of little use unless they direct fire crews towards suitable safety zones, which can be geospatially identified and evaluated.

    “However, escape routes are of little use unless they direct fire crews towards suitable safety zones, which can be geospatially identified and evaluated [27,28].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [27] Campbell, 2017, Safe separation distance score: A new metric for evaluating wildland firefighter safety zones using lidar, Int. J. Geogr. Inf. Sci. source
    • cites [28] Dennison, 2014, Identification of firefighter safety zones using lidar, Environ. Model. Softw. source

  • Probably not a substantial claim. It may state two separate claims as one.

    Interpretationreasoning

    If an orderly escape breaks down and crew members get separated, group travel can no longer be assumed and the functions may have a reduced value.

    “Additionally, if an orderly escape breaks down and crew members get separated, group travel can no longer be assumed and the functions may have a reduced value.”
    Quote in the paperSubstantial claim

  • It may state two separate claims as one.

    Interpretationreasoning

    When these models are used to predict travel times, the error may not be substantial over short distances but would amplify as distances increase.

    “When these models are used to predict travel times, the error may not be substantial over short distances but would amplify as distances increase.”
    Quote in the paperNot a substantial claim

  • It may state two separate claims as one.

    Study design and conductown data

    Although ground surface condition was not explicitly measured, the travel rate data were gathered from firefighters traversing a variety of gravel and dirt roads and trails.

    “Although ground surface condition was not explicitly measured, the travel rate data gleaned from this study were gathered from firefighters traversing a variety of gravel and dirt roads and trails.”
    Quote in the paperSubstantial claim

  • It may state two separate claims as one.

    Premisecitation

    Ruby et al. [22] and Alexander et al. [23] found load to have a negative effect on travel rates; however, neither produced predictive models.

    “Both studies found load to have a negative effect on travel rates; however, neither produced predictive models.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [22] Ruby, 2003, Wildland firefighter load carriage: Effects on transit time and physiological responses during simulated escape to safety zone, Int. J. Wildland Fire source
    • cites [23] Alexander, M.E., Baxter, G.J., and Dakin, G.R. (2005, January 26–28). Travel rates of Alberta wildland firefighters using escape routes. Proceedings of the Eighth International Wildland Fire Safety Summit, Missoula, MT, USA.

  • It may state two separate claims as one.

    Interpretationown data

    The moderate model's superior performance makes sense because points tend to be normally distributed by slope, with the highest density of points occurring around the 50th percentile.

    “This makes sense given that points tend to be normally distributed by the slope, with the highest density of point occurring around the 50th percentile (Figure 3).”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Premisecitation

    Campbell et al. [29] found that the Lorentz function form was best at estimating slope-travel rate relationships across a wide range of percentiles.

    “They found that the Lorentz function form was best at estimating slope-travel rate relationships across a wide range of percentiles:”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [29] Campbell, 2019, Using crowdsourced fitness tracker data to model the relationship between slope and travel rates, Appl. Geogr. source

  • Probably not a substantial claim.

    Interpretationown data

    With these newly developed models, wildland firefighter personnel do not need to rely on intuition or over-generalized travel rate models to accurately predict how long it would take a group of firefighters to travel along an escape route to safety.

    “Although effects such as fatigue, panic, and trail quality were not included in the study, with these newly developed models, wildland firefighter personnel do not need to rely on intuition or over-generalized travel rate models to accurately predict how long it would take a group of firefighters to travel along an escape route to safety.”
    Quote in the paperSubstantial claim

  • It may state two separate claims as one.

    Study design and conductreasoning

    Although this study modeled travel rates while participants carried heavy loads, the load effects were not explicitly modeled.

    “Although this study modeled travel rates while participants carried heavy loads, the load effects were not explicitly modeled.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim.

    Premisereasoning

    Quantile regression was chosen because of its ability to build a flexible model, accounting for the natural variability in human travel rates.

    “Quantile regression was chosen because of its ability to build a flexible model, accounting for the natural variability in human travel rates.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim.

    Interpretationreasoning

    Firefighters could have less of a performance decrease on steeper slopes than the general public due to both the physical fitness of firefighters and their training.

    “Firefighters could have less of a performance decrease on steeper slopes than the general public due to both the physical fitness of firefighters and their training.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The average person does not regularly hike long distances or travel on steep surfaces.
    • Rests on an assumption: Firefighters are in peak physical shape and train to travel through steep terrain regularly.

  • Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

    Premisecitation

    Irmischer and Clarke's function is based on the movement of military cadets, who may possess similar travel rate characteristics to the firefighting population.

    “Irmischer and Clarke [35]'s function is based on the movement of military cadets, who may possess similar travel rate characteristics to the firefighting population.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [35] Irmischer, 2018, Measuring and modeling the speed of human navigation, Cartogr. Geogr. Inf. Sci. source

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Premisecitation

    Campbell et al.'s slope-travel rate function was used as the basis of predicting egress in the Escape Route Index.

    “Campbell et al. [29]'s slope-travel rate function was used as the basis of predicting egress in the Escape Route Index [24].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [29] Campbell, 2019, Using crowdsourced fitness tracker data to model the relationship between slope and travel rates, Appl. Geogr. source
    • cites [24] Campbell, M.J., Page, W.G., Dennison, P.E., and Butler, B.W. (2019). Escape Route Index: A Spatially-Explicit Measure of Wildland Firefighter Egress Capacity. Fire, 2. source

      Checked before — its earlier verdict is held back until a new check runs.

  • Probably not a substantial claim.

    Interpretationreasoning

    Increasing the number of models would come at the cost of greater difficulty in choosing the best model to apply to a given situation.

    “However, the increased number of models would come at the cost of a greater difficulty in choosing the best model to apply to a given situation.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim. It may be too vague to check against evidence. The paper may give no reason why it holds.

    Premisenone given

    To effectively utilize escape routes, the rate at which firefighters can travel across a given route must first be understood.

    “To effectively utilize escape routes, the rate at which firefighters can travel across a given route must first be understood.”
    Quote in the paperNot a substantial claim

  • It may state two separate claims as one.

    Premisecitation

    Previous pedestrian travel rate functions were not derived from data specific to firefighters and assume no load carriage.

    “These functions were not derived from data specific to firefighters, and assume no load carriage.”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [29] Campbell, 2019, Using crowdsourced fitness tracker data to model the relationship between slope and travel rates, Appl. Geogr. source
    • cites [30] Naismith, 1892, Snowcraft in Scotland, Scott. Mt. Club J.

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [31] Tobler, W. (1993). Three Presentations on Geographical Analysis and Modeling.

  • Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds. It may state two separate claims as one.

    Interpretationnone given

    Past models may be better at predicting aggregated travel rates for an activity with breaks, but not as good at predicting instantaneous travel rates.

    “Past models may be better at predicting aggregated travel rates for an activity with breaks, but not as good at predicting instantaneous travel rates.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim. It may state two separate claims as one.

    Interpretationreasoning

    In an emergency situation where firefighters drop their packs and run to evacuate, these functions no longer apply and travel rates would be expected to increase.

    “In an emergency situation, where firefighters drop their packs and run to evacuate, these functions no longer apply and travel rates would be expected to increase.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: Travel rate predictions made from the functions presented in this study assume load carriage.

  • Probably not a substantial claim. It may state two separate claims as one.

    Premisecitation

    Better travel rate functions over complex terrain and integration of this information into a safety zone assessment have been identified as wildland firefighter safety research needs.

    “Better travel rate functions over complex terrain and integration of this information into a safety zone assessment have been identified as wildland firefighter safety research needs [14].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [14] Page, 2019, A review of US wildland firefighter entrapments: Trends, important environmental factors and research needs, Int. J. Wildland Fire source

      Checked before — its earlier verdict is held back until a new check runs.

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Study design and conductown data

    Out of 11 IHCs that agreed to collect data, 85 firefighters carried GPS units.

    “Out of the 11 IHCs that agreed to collect data, 85 firefighters carried GPS units.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Premisecitation

    Tobler's hiking function has been applied in a variety of contexts for predicting slope-controlled travel rates, including wildland firefighter safety.

    “Tobler's hiking function [31] has been applied in a variety of contexts for predicting slope-controlled travel rates, including wildland firefighter safety [26].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [31] Tobler, W. (1993). Three Presentations on Geographical Analysis and Modeling.
    • cites [26] Fryer, 2013, Wildland firefighter entrapment avoidance: Modelling evacuation triggers, Int. J. Wildland Fire source

  • Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

    Study design and conductown data

    In total, 732 h of data were collected at elevations ranging from 263 to 2418 m above sea level.

    “In total, 732 h, or almost 31 days, worth of data were collected at elevations ranging from 263 to 2418 m above sea level.”
    Quote in the paperNot a substantial claim

  • It may state two separate claims as one.

    Interpretationown data

    The models are unbiased and are not prone to consistent overestimation or underestimation of travel rates.

    “All three models had bias values close to 0 m/s, indicating the models are unbiased, and are not prone to consistent overestimation or underestimation of travel rates.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

    Study design and conductown data

    These firefighters collected data for 44 hikes over 9 different trails, totaling 209 km.

    “These firefighters collected data for 44 hikes over 9 different trails, totaling 209 km.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim. The paper may give no reason why it holds.

    Interpretationnone given

    The travel rate of the group is dependent on the slowest member of the group, regardless of the load they bear.

    “While group size may vary, the travel rate of the group is dependent on the slowest member of the group, regardless of the load they bear.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim. The paper’s conclusions may not depend on it.

    Interpretationnone given

    The models produced could be applied to personnel with similar experience and fitness levels such as search and rescue teams, park rangers, or even experienced hikers and backpackers.

    “While the primary focus of this study was to model travel rates for Type 1 firefighters, the models produced could be applied to personnel with similar experience and fitness levels such as search and rescue teams, park rangers, or even experienced hikers and backpackers.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim.

    Study design and conductnone given

    Fire season had not yet begun for the crews collecting data.

    “However, fire season had not yet begun for the crews collecting data.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim. It may be too vague to check against evidence.

    Interpretationreasoning

    The results of this study can be used by firefighters to choose a high, moderate, or low travel rate model to predict travel times depending on the situation at hand.

    “The results of this study can be used by firefighters to choose a high, moderate, or low travel rate model to predict travel times depending on the situation at hand.”
    Quote in the paperNot a substantial claim
49 of 49

  • The paper relies on this without support.

    Firefighters did not record any sprints during data collection.

    “Since firefighters did not record any sprints, we decided to filter out all speeds over 7 m/s, or approximately 15.7 mph, to get rid of these erroneous points, as this threshold represents the limits of reasonable pedestrian movement.”

  • The authors state this as an assumption.

    Atypical slope-travel rate records were the result of unique training practices that do not represent normal hiking conditions or mixing running and hiking within the same activity.

    “Those that did not (e.g., variable movement on flatter and steeper slopes) were assumed to be the result of some combination of unique training practices that do not represent normal hiking conditions or mixing running and hiking within the same activity.”

  • The paper relies on this without support.

    Firefighters are likely to be carrying loads exceeding 15 kg (33 lbs).

    “Firefighters are likely to be carrying loads exceeding 15 kg (33 lbs), and studies have found that carrying a load has a significant effect on travel rate [22,23,36,37].”

  • The paper relies on this without support.

    Firefighters' fitness and experience traversing diverse terrain are likely greater than nonfirefighters.

    “Previous pedestrian travel rate models also fail to capture the unique physical characteristics of firefighters, whose fitness and experience traversing diverse terrain are likely greater than nonfirefighters.”

  • The paper relies on this without support.

    Comparably little effort has been directed at quantitative definitions of attributes that define effective escape routes.

    “While fire behavior has been extensively researched and modeled e.g.[16][17][18], comparably little effort has been directed at quantitative definitions of attributes that define effective escape routes.”

  • The paper relies on this without support.

    The average person does not regularly hike long distances or travel on steep surfaces.

    “The average person does not regularly hike long distances or travel on steep surfaces.”

  • The paper relies on this without support.

    Firefighters are in peak physical shape and train to travel through steep terrain regularly.

    “In contrast, firefighters are in peak physical shape and train to travel through steep terrain regularly.”

  • The authors state this as an assumption.

    Travel rate predictions made from the functions presented in this study assume load carriage.

    “However, it should be noted that travel rate predictions made from the functions presented in this study assume load carriage.”

  • The paper relies on this without support.

    Firefighters in training are expected to be in the same physical condition they will maintain throughout the fire season.

    “Firefighters in training are expected to be in the same physical condition they will maintain throughout the fire season.”

  • The authors state this as an assumption.

    The data collected throughout the study are similar to how crews travel during the fire season and are representative of real firefighting situations.

    “Consequently, the data collected throughout the study are assumed to be similar to how crews travel during the fire season and are representative of real firefighting situations.”
10 of 10

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Existing travel rate functions fail to sufficiently account for the vast diversity of landscape conditions that impede foot travel.

    “Although a number of existing travel rate functions exist, they fail to sufficiently account for the vast diversity of landscape conditions that impede foot travel3–11.”

    From A singular, broadly-applicable model for estimating on- and off-path walking travel rates using airborne lidar data (2024) · cites this paper as [8]

    The Introduction says existing pedestrian travel-rate functions focus particularly on slope and that better functions for complex terrain are needed. It identifies specific shortcomings for firefighters—load carriage, physical characteristics, and emergency movement—but does not establish the broader claim that existing functions fail to account for the vast diversity of landscape conditions that impede foot travel. (LLM, conf=0.82)

    Experimental — accuracy not yet measured

  • The function form of Eq. (1) is a suitable basis for modeling travel rates.

    “Based on our previous work5,8,39 and preliminary testing, we identified the function form of Eq. (1) as a suitable basis for modeling.”

    From A singular, broadly-applicable model for estimating on- and off-path walking travel rates using airborne lidar data (2024) · cites this paper as [8]

  • Slope had the highest variable importance, and the partial dependence pattern between slope and travel rates in this dataset closely resembles the asymmetrical Lorentz functions used to predict travel rate in previous studies.

    “Slope had the highest variable importance and based on partial dependence the pattern between slope and travel rates in this dataset closely resembles the asymmetrical Lorentz functions used to predict travel rate in previous studies (Campbell et al., 2022;Sullivan et al. 2020) (Figure 8A).”

    From Machine learning estimation of off-trail pedestrian travel rates using LiDAR-derived slope, vegetation, and surface roughness (2026) · cites this paper as Sullivan et al. 2020

Citations

Cites

Flagged first, then by citations

2 of the 34 references couldn’t be matched to a known paper.

Research works printed but not linked: 7

  1. Pyne, S.J., Andrews, P.L., and Laven, R.D. (1996). Introduction to Wildland Fire, John Wiley and Sons, Inc.
  2. Gleason, 2004, LCES—A key to safety in the wildland fire environment, Fire Manag. Today, 52, 70
  3. Alexander, 2004, Forecasting wildland fire behavior: Aids, guides, and knowledge-based protocols, Fire Manag. Today, 64, 21
  4. Putnam, 1995, Analysis of escape efforts and personal protective equipment on the South Canyon Fire, SAFE J., 26, 34
  5. Beighley, 1995, Beyond the safety zone: Creating a margin of safety, Fire Manag. Notes, 55, 21
  6. Butler, B.W., Cohen, J.D., Putnam, T., Bartlette, R.A., and Bradshaw, L.S. (2000, January 10–12). A method for evaluating the effectiveness of firefighter escape routes. Proceedings of the 4th International Wildland Fire Safety Summit, Edmonton, AB, Canada.
  7. Naismith, 1892, Snowcraft in Scotland, Scott. Mt. Club J., 2, 157

Cited by

Sorted by citations

Related

Metadata

Authors
Sullivan, P. R., Campbell, M. J., Dennison, P. E., Brewer, S. C., & Butler, B. W.
Affiliations
  • Department of Geography, University of Utah, Salt Lake City, UT 84112, USA
  • Rocky Mountain Research Station, USDA Forest Service, Missoula, MT 59808, USA
ORCID
Venue
Fire
Publisher
MDPI AG
Published
2020-09-15
Volume
3
Issue
3
Pages
52
ISSN
2571-6255 (ISSN-L)
DOI
10.3390/fire3030052
OpenAlex
W3084596704
Cited by
20
References
34
Citations by year
2026: 4 · 2025: 4 · 2024: 7 · 2023: 2 · 2022: 3
FWCI
0.91
Type
journal article
Language
en
Open access
Licence
Locations
  • Fire (publishedVersion, cc-by)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
Funders
  • USDA Forest Service National Fire Plan (18JV11221637153)
  • National Wildfire Coordinating Group (19JV11221637142)
Topics
  • Health Sciences › Medicine › Public Health, Environmental and Occupational Health › Occupational Health and Performance
  • Physical Sciences › Engineering › Safety, Risk, Reliability and Quality › Fire dynamics and safety research
  • Physical Sciences › Environmental Science › Global and Planetary Change › Fire effects on ecosystems
Keywords
terrain slope, evacuation routes, GPS tracking, hiking, quantile regression, firefighter safety, airborne laser scanning

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

A language model drew the claims from the paper on 2026-11-09, under version 3 of the claim definition (model deepseek-v4.1-flash, prompt extract-v3).

A second model labelled each claim on 2026-11-09 (model jev-1.13-20260917, definition revision gold-guideline-v0.2).

Cited sources are checked with a language model’s help (gpt-6-sol).

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

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