1. t TNO Human Factors Driving behaviour effects of the Chauffeur Assistant Jeroen Hogema

2. t 16 December 20032 Overview Background Method TNO driving simulator Simulating the CA Experimental design Results Conclusions consequences for traffic simulation model

3. t 16 December 20033 Dutch Evaluation of the Chauffeur Assistant (DECA) Chauffeur Assistant Adaptive Cruise Control Lane Keeping System Follow-up of Lane Departure Warning Assistant FOT Transport Research Centre (TRC) Ministry of Transport, Public Works, and Water Management

4. t 16 December 20034 Chauffeur Assistant: Questions Individual driver level driving behaviour workload acceptance traffic flow level traffic performance safety indicators

5. t 16 December 20035 DECA DRIVING SIMULATO R behaviour TNO MIXIC interpretation report MIXIC simulations TR C workload acceptance driver CA

6. t 16 December 20036 Method – Driving simulator visual audio steering force motion

7. t 16 December 20037 Method – Driving simulator DAF 95XF lorry Mass 20500 kg (fully loaded) Maximum engine power: 350 kW Parameter set from DAF trucks

8. t 16 December 20038 Method – Simulating the CA Adaptive Cruise Control DC specifications Distance law for car-following Dref = 6.0 + 1.3 * v Dref = ACC's intended following distance (m) v=current speed (m/s) Braking: max. -3 m/s 2

9. t 16 December 20039 Method – Simulating the CA ACC controller structure from earlier work parameters from recent ACC work by TNO Automotive

10. t 16 December 200310 Method – Simulating the CA ACC reference scenarios approaching braking lead car accelerating lead car cut-in Dynamic behaviour of reference model driving simulator CA MIXIC CA

11. t 16 December 200311 Method – Simulating the CA LKS noise added to obtain realistic servo performance SDLP about 10 cm

12. t 16 December 200312 Method - Experimental design (1) with vs without CA traffic volume low (3400/u) high (6000/u) 3-lane motorway, 3.5 m wide lanes ACC headway D ref = 6.0 + t k * v t k = 1.0 – 1.3 – 1.6 s 1 preferred setting selected by each driver prior to experiment

13. t 16 December 200313 Method - Experimental design (2) Scenarios car-following (overtaking possible) braking lead car 3 m/s 2 4 m/s 2 Subjects 18, professional truck drivers at least 5 years 'groot rijbewijs' age between 25-55 paid for their participation

14. t 16 December 200314 Human Machine Interface driver turns CA turns on/off switches brake pedal driver sets ACC speed buzzer at maximum braking display ACC set speed on speedometer symbol: headway control or speed control

15. t 16 December 200315 Results – preferred CA time headway 1.0 s 1 x 1.3 s 8 x 1.6 s 9 x Total18 x

16. t 16 December 200316 Results – SD lateral position effect of CA

17. t 16 December 200317 Results – Time to Line Crossing effect of CA

18. t 16 December 200318 Results – close following effect of CA

19. t 16 December 200319 Results – lane change frequency effect of CA on edge of marginal significance [p<.11]

20. t 16 December 200320 Braking lead car: lane change response lane change reaction of subject Fewer lane changes with CA

21. t 16 December 200321 Braking lead car: braking response braking reaction of subject lower deceleration levels with CA

22. t 16 December 200322 Results – mental effort Rating Scale of Mental Effort effect of CA

23. t 16 December 200323 Acceptance (1) MeanStd.Dev. useful-useless 1.20.7 pleasant-unpleasant 1.30.9 good-bad 1.10.8 nice-annoying 0.91.1 effective-superfluous 1.10.9 likeable-irritating 1.30.7 assisting-worthless 1.40.8 desirable-undesirable 1.20.9 raising alertness-sleep inducing -0.21.1 -2..2 scales:

24. t 16 December 200324 Acceptance (2) Underlying variables USEFULNESS: + 0.93 SATISFACTION: + 1.10

25. t 16 December 200325 Summary of results (1) With Chauffeur Assistant… reduced SD of lateral position higher Time to Line Crossings less short time headways reduced Mental Effort (fewer changes with CA?)

26. t 16 December 200326 Summary of results (2) Acceptance: positive except “sleep-inducing” Lane changes fewer changes with CA? Braking lead car fewer lane changes with CA less critical behaviour with CA (maximum deceleration, minimum TTC) No effects on: mean, s.d. speed lane use (% right lane) mean lateral position mean time headway

27. t 16 December 200327 Chauffeur Assistant in MIXIC drivervehicle CA

28. t 16 December 200328 Chauffeur Assistant in MIXIC DRIVER VEHICLE CA car following free driving lane change model LATERAL LONGITUDINAL settings transitions CA

29. t 16 December 200329 MIXIC driver model Driver – CA CA settings CA reference speed = driver’s intended speed CA reference headway: 50% 1.3 s; 50% 1.6 s CA off when: CA is braking hard AND driver would brake harder starting lane-change manoeuvre CA on when: “possible”

30. t 16 December 200330 MIXIC driver model Lane change behaviour small effects nature of effects unknown tactical level: avoid getting 'stuck' in car-following in a 'slow' lane driver-state related: reduced alertness, complacency, less 'active' driving => no changes in lane change model

31. t 16 December 200331 Conclusions Behaviour Workload effects in line with ACC or LKS research Acceptance } Chauffeur Assistant – ACC + LKS: contribution of ACC and LKS unknown Minor modifications to MIXIC->driver->ACC model