Heterogeneous Treatment Effects of Speed Cameras on Road Safety
This paper aims to analyze the heterogeneous treatment effects of fixed speed cameras and evaluate the criteria of camera sites selection. The authors employ a nonparametric method to estimate how treatment effects continuously change against propensity scores. They first estimate individual treatment effect for each treated site using propensity score matching. Then treatment effects are estimated as a function of propensity scores using local polynomial regression. The results show that the effects of speed cameras are not uniform across the treated sites and are dependent of sites characteristics, measured by propensity scores. The authors further evaluate the criteria for selecting camera sites in the UK by comparing the effects on treated sites meeting and not meeting the criteria. The results show that camera sites which meet the criteria perform better in reducing casualties, implying the site selection criteria are rational.
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Supplemental Notes:
- This paper was sponsored by TRB committee ANB40 Traffic Law Enforcement.
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Corporate Authors:
500 Fifth Street, NW
Washington, DC United States 20001 -
Authors:
- Li, Haojie
- Graham, Daniel J
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Conference:
- Transportation Research Board 94th Annual Meeting
- Location: Washington DC, United States
- Date: 2015-1-11 to 2015-1-15
- Date: 2015
Language
- English
Media Info
- Media Type: Digital/other
- Features: Figures; References; Tables;
- Pagination: 19p
- Monograph Title: TRB 94th Annual Meeting Compendium of Papers
Subject/Index Terms
- TRT Terms: Cameras; Crash injuries; Intersections; Mathematical methods; Speed
- Geographic Terms: United Kingdom
- Subject Areas: Highways; Operations and Traffic Management; Safety and Human Factors; I85: Safety Devices used in Transport Infrastructure;
Filing Info
- Accession Number: 01550171
- Record Type: Publication
- Report/Paper Numbers: 15-2052
- Files: TRIS, TRB, ATRI
- Created Date: Jan 16 2015 8:29AM