STANDARDIZED NAMES AND DEFINITIONS FOR DRIVING PERFORMANCE MEASURES A thesis submitted by Mark R. Savino In partial fulfillment of the requirements for the degree of Master of Science In Human Factors Engineering TUFTS UNIVERSITY May 2009 Adviser: Dr. Paul A. Green Abstract Historically, driving performance measures have been undefined or vaguely defined, and if defined, inconsistently used. Consequently, driving studies are difficult to compare and challenging to replicate, undermining the professional credibility of researchers and the field of automotive human factors. This study developed names and definitions for 12 common lateral and longitudinal driving performance measures relating to: driving within and between lanes (lane departure, lane change, lateral lane position); steering wheel reversal; headway and gap (distance gap, time gap, distance headway, time headway); pedals (accelerator release time, accelerator to brake transition time, brake reaction time); and time to collision) Human factors and lexicographical criteria were developed for defining driving performance operational definitions. Based on the criteria and literature, standard measure names and definitions were developed. It is intended that human factors engineers and researchers will use these definitions for research and design, consequently providing a more consistent and comparable evaluation processes. ii Acknowledgements I would like to thank my advisers Paul Green, Dan McGehee, and Anil Saigal for their advice and expertise. I thank the Society of Automotive Engineers for their enthusiasm and patience and the staff of UMTRI Human Factors Department, especially Jim Sayer, for providing me with the resources necessary to complete this work. The incredible practical and emotional support provided by Tina Sayer and Emily Nodine was invaluable. Finally, I want to thank my parents for being my cheerleaders, and for helping me to think positively, even when work seemed overwhelming. iii Table of Contents Preface .......................................................................................................1 Definitions for Terms Used in This Work ....................................................1 Notes ..........................................................................................................3 Introduction .................................................................................................4 Procedure ...................................................................................................7 1. Identify key human factors literature to review and establish a systematic investigation process ........................................................8 2. Select most commonly cited and used driving performance measurement terms and definitions .................................................. 10 3. Determine collection and cataloguing techniques; collect driving performance measurement terms and definitions ............................. 11 4. Determine analysis techniques; analyze driving performance measurement terms and definitions .................................................. 13 Lexicographical criteria. .....................................................................14 Other notes related to data analysis. ................................................. 22 5. Propose standardized driving performance measurement terms and definitions ..................................................................................23 Results .....................................................................................................24 Lane Departure .....................................................................................24 Background. ......................................................................................24 Which names have been used? ........................................................ 26 How should lane departure be defined? ............................................ 29 Lane Change ........................................................................................33 Background. ......................................................................................33 Which names have been used? ........................................................ 34 How should lane change be defined? ............................................... 34 Time-to-line crossing (TLC) ...................................................................36 Background. ......................................................................................36 Which names have been used? ........................................................ 36 How should time-to-line crossing be defined? ................................... 37 Lateral Lane Position ............................................................................38 Background. ......................................................................................38 Which names have been used? ........................................................ 38 How should lateral lane position be defined? .................................... 39 Steering Wheel Reversal ......................................................................42 Background. ......................................................................................42 Which names have been used? ........................................................ 43 How should steering wheel reversal be defined? .............................. 44 Headway/Gap .......................................................................................47 Background. ......................................................................................47 Which names have been used? ........................................................ 49 How should headway/gap be defined? .............................................. 50 Accelerator Release Time .....................................................................53 Background. ......................................................................................53 iv Which names have been used? ........................................................ 54 How should accelerator release time be defined? ............................. 55 Accelerator to Brake Transition Time .................................................... 56 Background. ......................................................................................56 Which names have been used? ........................................................ 56 How should accelerator to brake transition time be defined? ............ 57 Brake Reaction Time ............................................................................58 Background. ......................................................................................58 Which names have been used? ........................................................ 58 How should brake reaction time be defined? ..................................... 59 Time to Collision (TTC) ......................................................................... 61 Background. ......................................................................................61 Which names have been used? ........................................................ 61 How should time to collision be defined? .......................................... 62 Discussion ................................................................................................64 Measure names ....................................................................................65 Measure definitions ...............................................................................66 Definition classification ......................................................................66 Lane departure. ................................................................................. 67 Lane departure definition 1 (crash potential). .................................... 67 Lane departure definition 2 (ease of measurement). ......................... 68 Lane change. .....................................................................................70 Lateral lane position definition 1a and b (ease of measurement). ..... 70 Lateral lane position definition 2 (alternate). ...................................... 71 Time-to-line crossing. ........................................................................71 Steering wheel reversal. ....................................................................74 Distance gap. ....................................................................................74 Distance headway. ............................................................................74 Time gap. ..........................................................................................75 Time headway. ..................................................................................75 Accelerator pedal release reaction time. ........................................... 76 Accelerator pedal to brake pedal transition time ................................ 76 Brake reaction time. ..........................................................................76 Time to collision. ................................................................................77 References ...............................................................................................80 Appendix A – Lane departure definitions ................................................ 102 Appendix B – Lane Change ....................................................................107 Appendix C – Time-to-line crossing .......................................................