Transcript Lecture 4 - Predictive Methods

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Topic 4 – Predictive Method
HSM Volume 2
CEE 763
CEE 763
Fall 2011
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HSM PREDICTIVE METHOD
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Estimate expected crash frequency
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Use SPF and CMF
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SPF for base conditions
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HSM includes SPF for three types of facilities
N predicted  N SPF ,x  ( CMF1x  CMF2 x  .....CMFyx )  C x
CEE 763
Fall 2011
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SPF for Urban/Suburban Arterial Intersections
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Intersection type: 3ST, 4ST, 3SG, 4SG
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SPF to forecast four types of collision:
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Multiple vehicle
Single vehicle
Vehicle-pedestrian
Vehicle-bicycle
Total expected crash will be the sum of all four
collision types
N predicted  N SPF ,x  ( CMF1x  CMF2 x  .....CMFyx )  C x
CEE 763
Fall 2011
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SPF for Multiple-vehicle Collision
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SPF form
Nmv  e
CEE 763
a b ln( AADTmaj )
 c* ln( AADTmin )
Fall 2011
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CEE 763
Fall 2011
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