nectar 2013

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Weather Lars Böcker Sofia Thorsson & Cycling

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Page 1: Nectar 2013

Weather  

Lars  Böcker  Sofia  Thorsson  

&  Cycling  

Page 2: Nectar 2013

•  Exis;ng  studies  lack  a>en;on  for  dura;ons  •  Exis;ng  studies  have  meteorological  shortcomings:  

–  Assumed  linear  rela;onships  

–  Thermal  condi;ons  are  only  analysed  by  air  temperatures  

– Weather  parameters  are  oFen  singled  out  

–  Need  for  analysing  the  integrated  effects  of  weather  

 

 

 

Background  

Page 3: Nectar 2013

Methods  

N   A$ri'on  

Wave  1:  Summer   950  

Wave  2:  Autumn   826   -­‐13,1%  

Wave  3:  Winter   718   -­‐13,0%  

Page 4: Nectar 2013

0

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25

-10

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Prec

ipita

tion

in m

m /

win

d sp

eed

in m

/s

Max

imum

air

tem

pera

ture

in ˚C

Wind speed (m/s)

Precipitation

Ta_max (observed)

Ta_max (1980-2010)

August September October November December January February

Wind Speed

Precipitation

Ta(max), observed

Ta(max), 1980-2010

Snow Cover

Methods  

Page 5: Nectar 2013

0

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25

-10

0

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20

30

40

Prec

ipita

tion

in m

m /

win

d sp

eed

in m

/s

Max

imum

air

tem

pera

ture

in ˚C

Wind speed (m/s)

Precipitation

Ta_max (observed)

Ta_max (1980-2010)

August September October November December January February

Wind Speed

Precipitation

Ta(max), observed

Ta(max), 1980-2010

Snow Cover

Methods  

Page 6: Nectar 2013

Descrip;ves:  modal  split  

0%

20%

40%

60%

80%

100%

Ta (max)

Bicycle Walking Public transport Car

20-­‐25˚C  100

0

%

Page 7: Nectar 2013

Descrip;ves:  modal  split  

0%

20%

40%

60%

80%

100%

Ta (max)

0%

20%

40%

60%

80%

100%

Precipitation (sum)

0%

20%

40%

60%

80%

100%

Ws (avg.)

Bicycle Walking Public transport Car

100

0

% 20-­‐25˚C  

Page 8: Nectar 2013

Descrip;ves:  cycling  frequencies  

0,0

0,2

0,4

0,6

0,8

1,0

1,2

1,4 Ta (max)

20-­‐25˚C  

Bicycle as main mode

Bicycle as access/egress to public transport

Page 9: Nectar 2013

Descrip;ves:  cycling  frequencies  

0,0

0,2

0,4

0,6

0,8

1,0

1,2

1,4 Ta (max)

0,0

0,2

0,4

0,6

0,8

1,0

1,2

1,4

Precipitation (sum)

0,0

0,2

0,4

0,6

0,8

1,0

1,2

1,4

Ws (avg.)

20-­‐25˚C  

Bicycle as main mode

Bicycle as access/egress to public transport

Page 10: Nectar 2013

Descrip;ves:  cycling  dura;ons  

0

5

10

15

20

25 Ta (max)

Bicycle as main mode

20-­‐25˚C  

25

0

5

10

15

20

min.

Page 11: Nectar 2013

Descrip;ves:  cycling  dura;ons  

0

5

10

15

20

25 Ta (max)

0

5

10

15

20

25

Precipitation (sum)

0

5

10

15

20

25

Ws (avg.)

Bicycle as main mode

25

0

5

10

15

20

min.

20-­‐25˚C  

Page 12: Nectar 2013

Mul;variate  analysis  

Meteorological  a$ributes  (Daily  level)  -­‐Maximum  Ta  -­‐Maximum  Tmrt  -­‐Maximum  PET  -­‐Precipita;on  sum  (between  6  and  12  a.m.)  -­‐Wind  speed    (between  6  and  12  a.m.)    

Cycling  behaviour  -­‐Mode  choice    -­‐Cycling  frequencies    (per  person  per  day)  -­‐Cycling  dura;on    (total  per  person  per  day)  

Page 13: Nectar 2013

Mul;variate  analysis  Spa'otemporal  a$ributes  -­‐Residen;al  environment  -­‐Weekday/weekend  -­‐Morning  peak/  evening  peak/off-­‐peak  day;me/offpeak  nigh`me  -­‐Daylight/darkness  

Personal  a$ributes  -­‐Age,  gender  -­‐Ethnicity  -­‐BMI  -­‐Educa;on  -­‐Weekly  work  dura;on  -­‐Working  hour  flexibility  -­‐Bicycle  ownership  -­‐Public  transport  card    Household  a$ributes  -­‐Household  type  -­‐Car  ownership  -­‐Household  income  -­‐Garden/balcony  size  -­‐House  air-­‐condi;oning    AAtudes/habits  -­‐Urban/countryside  person  -­‐Environmental  concern  -­‐A`tude  towards  seasons                

Meteorological  a$ributes  (Daily  level)  -­‐Maximum  Ta  -­‐Maximum  Tmrt  -­‐Maximum  PET  -­‐Precipita;on  sum  (between  6  and  12  a.m.)  -­‐Wind  speed    (between  6  and  12  a.m.)    

Cycling  behaviour  -­‐Mode  choice    -­‐Cycling  frequencies    (per  person  per  day)  -­‐Cycling  dura;on    (total  per  person  per  day)  

Trip  a$ributes  -­‐Trip  purpose  (work/study,  errands,  social  visit,  leisure)  -­‐Type  of  trip  (rou;ne,  planned,  impulsive  

Page 14: Nectar 2013

Three  thermal  parameters  

Air  temperature  (Ta)  

Page 15: Nectar 2013

Air  temperature  (Ta)   Mean  Radiant    Temperature  (Tmrt)  

Three  thermal  parameters  

Page 16: Nectar 2013

Air  temperature  (Ta)   Mean  Radiant    Temperature  (Tmrt)  

Physiological  Equivalent    Temperature  (PET)    à  Air  temperature    à  Radiant  heat  load    à  Wind  speed    à  Humidity  

Three  thermal  parameters  

Page 17: Nectar 2013

14 August 2012 - semi-cloudy day no precipitation, mean wind speed 1.3 m/s (1.1m)

0

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70

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Hour

Tem

pera

ture

C

Ta Tmrt PET

Ta  

Tmrt  

PET  

Three  thermal  parameters  

Weather  change:  from  clear  and  calm  to  cloudy  and  windy  

Page 18: Nectar 2013

Results:  mode  choice  Ta  model   Cycling  v  car   Walking  v  car   Publ.  transp.  v  car  

Ta  bell-­‐shaped  24˚C   +  Wind  speed   -­‐  Precipita;on  sum   -­‐  -­‐  

Tmrt  model   Cycling  v  car   Walking  v  car   Publ.  transp.  v  car  

Tmrt  bell-­‐shaped  52˚C   ++   -­‐  Wind  speed   -­‐  Precipita;on  sum   -­‐  -­‐  

PET  model   Cycling  v  car   Walking  v  car   Publ.  transp.  v  car  

PET  bell-­‐shaped  30˚C   +++  Precipita;on  sum   -­‐  -­‐  -­‐  

Mul'nomial  LOGIT  model  (clustered  S.E.)  

Wald  Chi2  =  3176    

Wald  Chi2  =  3242    

Wald  Chi2  =  3173    

Page 19: Nectar 2013

Results:  cycling  frequencies  

Tmrt  Model   #  Cycling  trips  /  person  /  day  

Tmrt  bell-­‐shaped  52˚C   +++  Wind  speed  

Precipita;on  sum   -­‐  -­‐  -­‐  

PET  (model)   #  Cycling  trips  /  person  /  day  

PET  bell-­‐shaped  33˚C   +++  Precipita;on  sum   -­‐  -­‐  -­‐  

Nega've  Binomial  model  (clustered  S.E.)  

Ta  Model   #  Cycling  trips  /  person  /  day  

Ta  bell-­‐shaped  24˚C   +++  Wind  speed  

Precipita;on  sum   -­‐  -­‐  

Wald  Chi2  =  407    

Wald  Chi2  =  428  

Wald  Chi2  =  415  

Page 20: Nectar 2013

Results:  cycling  dura;ons  Ta  (model)   Cycling  hours  /  person  /  day  

Ta  bell-­‐shaped  24˚C   +++  Ws   -­‐  -­‐  -­‐  Precip.   -­‐  -­‐  

Tmrt  Model   Cycling  hours  /  person  /  day  

Tmrt  bell-­‐shaped  52˚C   +++  Ws   -­‐  Precip.   -­‐  -­‐  -­‐  

PET  (model)   Cycling  hours  /  person  /  day  

PET  bell-­‐shaped  31˚C   +++  Precip.   -­‐  -­‐  -­‐  

TOBIT  model  (clustered  S.E.)  

Wald  Chi2  =  235    

Wald  Chi2  =  244    

Wald  Chi2  =  240    

Page 21: Nectar 2013

Summary  •  Thermal  condi;ons  have  non-­‐linear  bell  shaped  effects  on  cycling  

•  The  PET  and  Tmrt  models  perform  be>er  than  the  Ta  models  

•  Precipita;on  and  wind  have  nega;ve  linear  effects  on  cycling  •  Exchange  mostly  between  cycling  and  the  car,  less  for  other  modes  

•  Effects  on  dura'ons  are  stronger  than  on  frequencies  •  Effects  are  stronger  for  leisure  trips  than  for  u;litarian  trips    

 

 

 

Page 22: Nectar 2013

Conclusion  •  Cycling  is  most  sensi;ve  to  weather  

•  Complexity  weather  and  mobility  

•  Non  linear  rela;onships,  op;mums  and  thresholds  

•  Combining  parameters  (Tmrt  or  PET)  be>er  than  singling  out  (Ta)  

•  Nevertheless  Ta  is  s;ll  very  useful:  –  widely  available    –  easily  interpretable  –  compa;ble  to  weather  forecasts  and  climate  change    

 

 

Page 23: Nectar 2013

Thank  you!  Böcker  &  Thorsson  (2013)  Integrated  weather  effects  on  cycling  shares,  frequencies  and  dura;ons  in  Ro>erdam,  the  Netherlands  

 

Exis;ng  knowledge  on  weather  and  transport  mode  choices:    

Böcker,  Dijst  &  Prillwitz  (2013)  “Impact  of  weather  on  travel  behaviour  in  perspec;ve:    a  literature  review”,  Transport  Reviews  

               [email protected]  

 

                           Funded  by: