1. Dutch driving behavior analyses | Norbert Ligterink

2. Update
Analysis according to RDE (description in 2nd package + explanation HS)
Filtering, Trip composition, Sample size
Results Dutch trips
Rural + motorway: results do not contradict Commission proposal (based on analysis HS of WLTP-database)
Urban: higher v*apos-[95] – approx. 20 m2/s3 (intersection 19 m2/s3, compared to approx. 10 m2/s3 in Commission proposal)
Under discussion: Dutch approach (chase car) appropriate for Urban driving? (v*apos-[95] dominated by aggressive driver?; no trips in range 5 – 10 m2/s3?)
more or less fixed vehicle followed (single lane traffic)
limited time free-flow
Professional driver behaviour: no impact on results
2 | Dutch driving behavior
25 September 2015

3. using distance-average velocity
90 and above
60-90
0-60
3 | Dutch driving behavior
25 September 2015

4. Trip lengths trips designed for equal shares urban/rural/Mway
“natural trip”:
urban start  rural  motorway  rural  urban stop
combining two trips
for a minute trips
4 | Dutch driving behavior
25 September 2015

5. Hanning filter (N=3, SPSS)
raw acceleration:
ai+1/2 = (vi+1-vi)/3.6
Hanning filter (smoothing, as in SPSS, combined with Heinz definition of acceleration):
vi = 0.25*vi *vi *vi-1
ai = (vi+1-vi-1)/(2*3.6) = (0.125*vi *vi *vi *vi-2)/3.6
centrepoint definition from Heinz: additional smoothing
5 | Dutch driving behavior
25 September 2015

6. Driver experience urban driving:
more or less fixed vehicle followed (single lane traffic)
limited time free-flow (no car in front) (automatic gear AUDI)
rural and motorway driving:
following cars for at least 2-3 kilometres (limited vehicle variation)
large variation in driving styles observed
a number of times “let cars go” because of speed limit violations
6 | Dutch driving behavior
25 September 2015

7. Effect of minimal sample size affecting mainly rural data on this data
7 | Dutch driving behavior
25 September 2015

8. effect of the velocity definition
8 | Dutch driving behavior
25 September 2015

9. Effect of filtering/smoothing
9 | Dutch driving behavior
25 September 2015

10. Effect of the 90-minute trip length (two-trip combinations)
10 | Dutch driving behavior
25 September 2015

11. The percentiles of valid trips discarding 5% of the trips as driving boundary
11 | Dutch driving behavior
25 September 2015

12. Thank you for your attention