Road Weather Management Program
photos of lightning, trucks plowing snow, an empty road before a storm, and an evacuation
Office of Operations 21st century operations using 21st century technologies

Best Practices for Road Weather Management Version 2.0


A Correlation Technique for Estimating Traffic Speed from Cameras


This paper presents a new algorithm to estimate Speed from roadside cameras in uncongested traffic, congested traffic, favorable weather conditions, and adverse weather conditions. Individual vehicle lanes are identified and horizontal vehicle features are emphasized using a gradient operator. The features are projected into a one-dimensional subspace and transformed into a linear coordinate system using a simple camera model. A correlation technique is used to summarize the movement of features through a group of images and estimate mean speed for each lane of vehicles.


82nd Transportation Research Board (TRB) Annual Meeting, University of Washington. For an electronic copy of this resource, please direct your request to

Date: 2003


Schoepflin, Dailey


Closed Circuit Television (CCTV)

PDF files can be viewed with the Acrobat® Reader®.

Office of Operations