Study Details
Study Title: An Analysis of the Safety Effectiveness of Pavement Marking Retroreflectivity
Authors: Smadi et al.
Publication Date:JAN, 2008
Abstract: It has been shown in previous research that greater longitudinal pavement marking retroreflectivity levels increase drivers' visibility and detection distance. However, increased visibility may also cause drivers to feel too comfortable during nighttime conditions and drivers may then pay less attention and/or operate at unsafe speeds. Before-and-after studies have been conducted on pavement marking improvements such as repainting stripes or changing to a more durable marking material. Studies have also used models to estimate the retroreflectivity based on date of installation and vehicle exposure, or assumed a linear reduction in retroreflectivity over time. Only two studies have related field-measured pavement marking retroreflectivity to safety performance (crash data). The study analyzed the relationship between three years of pavement marking retroreflectivity data collected by the Iowa DOT on all state primary roads and corresponding crash and traffic data. The study developed a spatial-temporal database using measured retroreflectivity data to account for the deterioration of pavement markings over time along with a statewide crash database to attempt to quantify a relationship between crashes and the quality (measured by retroreflectivity) of pavement marking. Three different sets of data were analyzed: the complete database, two-lane roads, and records with retroreflectivity values less than or equal to 200 mcd/m2/lx only. The distributions and models of the entire database and the two-lane records did not show that poor pavement marking retroreflectivity correlated to a higher crash probability. However, when looking solely at records with retroreflectivity values of 200 or less, a statistically significant, albeit weak relationship was determined.
Study Citation: Smadi, O., R.R. Souleyrette, D.J. Ormand, and N. Hawkins (2008). An Analysis of the Safety Effectiveness of Pavement Marking Retroreflectivity. 87th Annual Meeting of the Transportation Research Board, Paper No. 08-2471, TRB 2008 Annual Meeting CD-ROM.
CMFs Associated With This Study
Category: Delineation
Countermeasure: Increase pavement marking retroreflectivity
| CMF | CRF(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
|---|---|---|---|---|---|---|
 | |  | Cross median,Fixed object,Frontal and opposing direction sideswipe,Head on,Nighttime,Run off road,Sideswipe,Single vehicle | All | Not Specified | Rural |
| |  | Cross median,Fixed object,Frontal and opposing direction sideswipe,Head on,Nighttime,Run off road,Sideswipe,Single vehicle | All | Not Specified | Rural |
| | | Cross median,Fixed object,Frontal and opposing direction sideswipe,Head on,Nighttime,Run off road,Sideswipe,Single vehicle | All | Not Specified | Rural |
