Examining the effect of daylight on road accidents and investigating a state space time series approach to modelling zero inflated count data
Examining the effect of daylight on road accidents and investigating a state space time series approach to modelling zero inflated count data
In this thesis two aspects of the modelling of road accident count data are investigated in detail. Under the first investigation the effect of daylight on road accidents is considered. Here, daylight is established as a significant cause of car occupant causalities in both Scotland and Southwest England using linear and log-linear regression models. It is also shown that there is a noticeable difference in the level of daylight during morning rush hour in December and January between Scotland and Southwest England due to the difference in latitude between two regions. Ad hoc methodology is then introduced to investigate the possibility that the difference in the level of daylight during morning rush hour will result in a significant difference in the numbers of car occupant causalities between the two regions during December and January.
The second investigation considers the use of a conditional Bernoulli truncated Poisson state space time series model for modelling zero inflated count data. Although it is technically complex, its appeal is likely to be broader than the daylight investigation as the methods presented here offer useful insight into the modelling of any zero inflated time series count data. The conditional Bernoulli truncated Poisson model has been used before to model zero inflated data, but it has not been used on time series data and has not been put into state space form. Difficult issues are raised by applying the conditional model to time series data and various methods are introduced and compared to overcome these problems.
University of Southampton
Dartnall, James Edward
66e07f69-c5a9-478f-b021-1c1b8b9c08d4
2007
Dartnall, James Edward
66e07f69-c5a9-478f-b021-1c1b8b9c08d4
Dartnall, James Edward
(2007)
Examining the effect of daylight on road accidents and investigating a state space time series approach to modelling zero inflated count data.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
In this thesis two aspects of the modelling of road accident count data are investigated in detail. Under the first investigation the effect of daylight on road accidents is considered. Here, daylight is established as a significant cause of car occupant causalities in both Scotland and Southwest England using linear and log-linear regression models. It is also shown that there is a noticeable difference in the level of daylight during morning rush hour in December and January between Scotland and Southwest England due to the difference in latitude between two regions. Ad hoc methodology is then introduced to investigate the possibility that the difference in the level of daylight during morning rush hour will result in a significant difference in the numbers of car occupant causalities between the two regions during December and January.
The second investigation considers the use of a conditional Bernoulli truncated Poisson state space time series model for modelling zero inflated count data. Although it is technically complex, its appeal is likely to be broader than the daylight investigation as the methods presented here offer useful insight into the modelling of any zero inflated time series count data. The conditional Bernoulli truncated Poisson model has been used before to model zero inflated data, but it has not been used on time series data and has not been put into state space form. Difficult issues are raised by applying the conditional model to time series data and various methods are introduced and compared to overcome these problems.
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Published date: 2007
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Local EPrints ID: 466108
URI: http://eprints.soton.ac.uk/id/eprint/466108
PURE UUID: 029821f1-8037-43ed-9356-ab1b40c7ab1b
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Date deposited: 05 Jul 2022 04:22
Last modified: 16 Mar 2024 20:31
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Author:
James Edward Dartnall
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