Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6936879 | Transportation Research Part C: Emerging Technologies | 2014 | 14 Pages |
Abstract
The work compared reported speeds from INRIX against the concurrent loop detector data, as detailed herein. Three issues became apparent: First, the reported INRIX speeds tend to lag the loop detector measurements by almost 6Â min. This latency appears to be within INRIX specifications, but from an operational standpoint it is important that time sensitive applications account for it, e.g., traffic responsive ramp metering. Second, although INRIX reports speed every minute, most of the time the reported speed is identical to the previous sample, suggesting that INRIX is effectively calculating the speeds over a longer period than it uses to report the speeds. This work observed an effective average sampling period of 3-5Â min, with many periods of repeated reported speed lasting in excess of 10Â min. Third, although INRIX reports two measures of confidence, these confidence measures do not appear to reflect the latency or the occurrence of repeated INRIX reported speeds.
Related Topics
Physical Sciences and Engineering
Computer Science
Computer Science Applications
Authors
Seoungbum Kim, Benjamin Coifman,