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Travel Time. Travel time estimated from initial speed TT error: TT est_av & TT i_tr. Error between TT tr_i and TT sms. TT tr_i – TT sms = TT tr_i – TT est_i + TT est_i – TT sms Error owing to the Error du to the average: - PowerPoint PPT Presentation
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Travel Time
Travel time estimated from initial speed TT error: TTest_av & TTi_tr
1 2 10 20 30 60 180 300 9000
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|SMS Ttest - TTtr_i||TMS TTest - TTtr_i||TTest_i - TTtr_i|
Agg. length (sec)
TT e
rror
(sec
)
1 2 10 20 30 60 180 300 9000
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|TTi_tr - TTsms|
300ft500ft1500ftPolynomial (1500ft)
Aggregation Width
TT e
rr
1 2 10 20 30 60 180 300 9000
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10
15
20
25
|TTi_tr - TTsms|
300ft500ftPolynomial (500ft)1500ft
Aggregation Width
TT e
rr
1 2 10 20 30 60 180 300 9000
5
10
15
20
25
|TTi_tr - TTsms|
300ftPolynomial (300ft)500ft1500ft
Aggregation Width
TT e
rr
Error between TTtr_i and TTsms
TTtr_i – TTsms = TTtr_i – TTest_i + TTest_i – TTsms
Error owing to the Error du to the average: assumption of a =time aggregation
constant speed between 2 loop detectors
Prevalence of the errors?
300ft 500ft 1500ft0
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|TTi_tr - TTi_e||TTi_e - TTsms|
Aggregation Width
MA
E (s
ec)
Error between TTtr_i and TTsms
• Variability over distance can prevail upon variability over distance
Error between TTtr_i and TTsms
Error & traffic conditions
1 2 10 20 30 60 180 300 9000
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Spacing: 300ft
transitioncongestion
Aggregation Width (sec)
MAP
E
1 2 10 20 30 60 180 300 9000
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60
Spacing: 1500ft
transitioncongestion
Aggregation Width (sec)
MAP
E
Fundamental diagram
