af Wåhlberg A.E. (1997): Time pressure, age and driving speed among bus drivers: A pilot study. Report to the National Board of Road Administration. Uppsala, Uppsala University, Department of Psychology: 11. Akay A.E., Erdas O., Sessions J. (2004): Determining productivity of mechanized harvesting machines. Journal of Applied Sciences, 100: 100–105.Belbo Helmer, Talbot Bruce (2014): Systems Analysis of Ten Supply Chains for Whole Tree Chips. Forests, 5, 2084-2105 https://doi.org/10.3390/f5092084 Berg S., Manner J. (2018): The influence of driving distance on the forwarders’ average speed in mid-Sweden. In: Proceedings of the NB-NORD workshop on Big data from forest machines: Ongoing and possible future R&D activities for forest operations. Ås, 19–20 June: 4–5.Cade Brian S., Noon Barry R. (2003): A gentle introduction to quantile regression for ecologists. Frontiers in Ecology and the Environment, 1, 412-420 https://doi.org/10.1890/1540-9295(2003)001[0412:AGITQR]2.0.CO;2 Carlsson D., Rönnqvist M., Westerlund A. (1998): Extraction of logs in forestry using operations research techniques. Linköping, Linköping University, Division of Optimization: 21. Core Team R. (2015): R: A language and environment for statistical computing. Vienna, Austria: the R Foundation for Statistical Computing.Flisberg Patrik, Forsberg Mattias, Rönnqvist Mikael (2007): Optimization based planning tools for routing of forwarders at harvest areas. Canadian Journal of Forest Research, 37, 2153-2163 https://doi.org/10.1139/X07-065 Ghaffarian M.R., Stampfer K., Sessions J. (2007): Optimum road spacing of forwarding operations: a case study in Southern Austria. In: Proceedings of Austro2007/FORMEC´07: Meeting the Needs of Tomorrows´ Forests – New Developments in Forest Engineering, Vienna, Heiligenkreuz, Oct 7–11, 2007: 1–11. Available at: https://www.formec.org/images/proceedings/2007/session_8_pdf/8_1_paper_ghaffarian_stampfer_sessions_austro_formec_2007.pdf Gullberg T. (1997): Tidsåtgångsmodell för skotning. [Time consumption model for off-road extraction of shortwood.] Uppsatser och Resultat nr 297. Uppsala, Swedish University of Agricultural Sciences, Department of Forest Technology: 29. (in Swedish) Klepac J., Rummer B. (2012): Off-road transport of pinyon/juniper. In: Proceedings of the 35th Council on Forest Engineering Annual Meeting, Engineering New Solutions for Energy Supply and Demand. New Bern, North Carolina, Sept 9–12, 2012: 1–11. Available at: https://www.srs.fs.usda.gov/pubs/ja/2012/ja_2012_klepac_001.pdfKoenker Roger (2004): Quantile regression for longitudinal data. Journal of Multivariate Analysis, 91, 74-89 https://doi.org/10.1016/j.jmva.2004.05.006 Koenker R.W., d’Orey V. (1987): Algorithm AS 229: Computing regression quantiles. Journal of the Royal Statistical Society: Series C (Applied Statistics), 36: 383–393. Koenker R.W., d’Orey V. (1994): Remark AS R92: A remark on Algorithm AS 229: Computing dual regression quantiles and regression rank scores. Journal of the Royal Statistical Society: Series C (Applied Statistics), 43: 410–414. Kuitto P.J., Keskinen S., Lindroos J., Oijala T., Rajamäki J., Räsänen T., Terävä, J. (1994): Puutavaran koneellinen hakkuu ja metsäkuljetus. [Mechanized cutting and forest haulage.] Tiedotus 410. Helsinki, Metsäteho: 64. (in Finnish) Kumazawa Y., Fujita M., Yamasaki A., Koyama K., Ichihara K., Oka M. (2011): Consideration about safety and efficient log transportation by forwarders. Journal of the Japan Forest Engineering Society, 26: 181–186. Lindroos O., Wästerlund I. (2013): Utvärdering av skotning med påhängsvagn. [Evaluation of forwarding with a trailer.] Umeå, Swedish University of Agricultural Sciences: 48. (in Swedish) Lu K., Bi H., Watt D., Strandgard M., Li W. (2017): Reconstructing the size of individual trees using log data from cut-to-length harvesters in Pinus radiata plantations: a case study in NSW, Australia. Journal of Forestry Research, 29: 13–33.Manner Jussi, Nordfjell Tomas, Lindroos Ola (2013): Effects of the number of assortments and log concentration on time consumption for forwarding. Silva Fennica, 47, - https://doi.org/10.14214/sf.1030Manner Jussi, Palmroth Lauri, Nordfjell Tomas, Lindroos Ola (2016): Load level forwarding work element analysis based on automatic follow-up data. Silva Fennica, 50, - https://doi.org/10.14214/sf.1546Matthews Gerald, Dorn Lisa, Hoyes Thomas W., Davies D. Roy, Glendon A. Ian, Taylor Ray G. (2016): Driver Stress and Performance on a Driving Simulator. Human Factors: The Journal of the Human Factors and Ergonomics Society, 40, 136-149 https://doi.org/10.1518/001872098779480569Nurminen Tuomo, Korpunen Heikki, Uusitalo Jori (2006): Time consumption analysis of the mechanized cut-to-length harvesting system. Silva Fennica, 40, - https://doi.org/10.14214/sf.346 Ranta T. (2002): Logging residues from regeneration fellings for biofuel production – a GIS-based availability and cost supply analysis. [Ph.D. Thesis] Lappeenranta, Lappeenranta University of Technology: 180. (in Finnish) R Studio Team (2015): RStudio: Integrated Development for R. Boston, RStudio. Available at: http://www.rstudio.com/.Snowdon P. (1991): A ratio estimator for bias correction in logarithmic regressions. Canadian Journal of Forest Research, 21, 720-724 https://doi.org/10.1139/x91-101Stradling S. G. (2007): Car driver speed choice in Scotland. Ergonomics, 50, 1196-1208 https://doi.org/10.1080/00140130701318681Martin Strandgard, Rick Mitchell, Mauricio Acuna (2017): Time consumption and productivity of a forwarder operating on a slope in a cut-to-length harvest system in a Pinus radiata D. Don pine plantation. Journal of Forest Science, 63, 324-330 https://doi.org/10.17221/10/2017-JFS Sundberg U., Silversides C.R. (1988): Operational Efficiency in Forestry. Dordrecht, Kluwer Academic Publishers: 221 Tufts R.A. (1997): Productivity and cost of the Ponsse 15-series, cut-to-length harvesting system in southern pine plantations. Forest Products Journal, 47: 39–46. Väkevä J., Kariniemi S., Lindroos J., Poikela A., Rajamäki J. Uusi-Pantti K. (2001): Puutavaran metsäkuljetuksen ajanmenekki. [Forwarding time consumption.] Metsätehon raportti 123. Helsinki, Metsäteho: 44. (in Finnish) Väätäinen K., Ikonen T., Ala-Ilomäki J., Sirén M., Lamminen S. Asikainen A. (2012): Kuljettajaa opastavat älykkäät järjestelmät ja niiden käyttö koneellisessa puunkorjuussa. [Intelligent operator tutoring systems for wood harvesting.] Working Papers of the Finnish Forest Research Institute. Vantaa, Metla: 40. (in Finnish) Ylimäki R., Väätäinen K., Lamminen S., Sirén M., Ala-Ilomäki J., Ovaskainen H., Asikainen A. (2012): Kuljettajaa opastavien järjestelmien tarve ja hyötypotentiaali koneellisessa puunkorjuussa. [Decision support systems in logging.] Working Papers of the Finnish Forest Research Institute. Vantaa, Metla: 70. (in Finnish)