title: A speed limit compliance model for dynamic speed display sign.
abstract: BACKGROUND
  Violating speed limits is a major cause of motor vehicle crashes. Various techniques have been adopted to ensure that posted speed limits are obeyed by drivers. This study investigates the effect of dynamic speed display signs (DSDSs) on drivers' compliance with posted speed limit.
  
  
  METHODS
  An extensive speed data collection upstream of, adjacent to, and downstream of DSDS locations on multiple road classes with different speed limits (25, 35, and 45 mph) was performed short-term and long-term after DSDS installation. Conventional statistical analysis, regression models, and a Bayesian network were developed to assess the DSDS's effectiveness.
  General compliance with speed limit (upstream of the DSDS location), time of day, day of week, duration of DSDS operation, and distance from the DSDS location were significantly correlated with speed limit compliance adjacent to the DSDS. While compliance with the speed limit due to the DSDS increased by 5%, speed reduction occurred in 40% of the cases.
  
  
  CONCLUSIONS
  Since drivers were likely to increase their speed after passing the DSDS, it should be installed on critical points supplemented with enforcement.
authors.affiliation: Department of Transportation and Urban Infrastructure Studies, Morgan State University, 1700 E. Cold Spring Lane, Baltimore, MD 21251, USA. Electronic address: anam.ardeshiri@morgan.edu.
authors.forename: Anam
authors.initials: A
authors.lastname: Ardeshiri
authors.affiliation: Department of Transportation and Urban Infrastructure Studies, Morgan State University, 1700 E. Cold Spring Lane, Baltimore, MD 21251, USA. Electronic address: mansoureh.jeihani@morgan.edu.
authors.forename: Mansoureh
authors.initials: M
authors.lastname: Jeihani
mesh_terms: D001334:Automobile Driving / Q000706:statistics & numerical data*; D001499:Bayes Theorem; D003625:Data Collection / Q000379:methods; D006801:Humans; D008962:Models, Theoretical
keywords: Bayesian network; DSDS; Speed compliance; Speed limit