BlueFax portable and real-time systems are being used to collect data to drive real-time travel time information to support a wide range of traffic and planning-oriented studies in the US, Canada, Europe, Australia, and elsewhere. BluFax equipment provides cost-effective, accurate travel time data on freeways, as well as arterial roadways. Data collected by BluFAX sensors to support real-time monitoring can be reprocessed to support studies and analysis needs.
The most extensive, long-term deployment of BluFax began in 2008 to validate GPS-based vehicle probe data procured by the I-95 Corridor Coalition from the Inrix Corporation in connection with its six-state Vehicle Probe Project. In all cases, the equipment performed flawlessly and provided reliable travel time measures. As part of this effort, twenty portable units continue to be relocated to different sites as the data validation proceeds. For this project, Bluetooth data represent "ground truth" because of the accuracy of data and large sample sizes. Floating car data, historically used as ground truth was cost prohibitive for ongoing validation testing. The BluFax data provides a baseline for validating GPS data acquired from Inrix, which in turn determines contract payment. Information on the I-95 Corridor Coalition Vehicle Probe Project: http://www.i95coalition.org/vehicle-probe.html
Evaluation of Signal Timing Changes
BluFax was used to assess the impact of signal retiming along arterial routes. BluFax makes it cost-effective to collect travel time data for several days to a week, 24/7 for prior to implementing changes, and for a similar period following changes. Data from BluFAX units were processed analyzed using BluSTATS. Once matched pairs for segments were processed, .csv output from BluSTATS was used to generate the frequency of delays (in seconds) encountered by vehicles before and after signal timing changes were implemented.
July 4, 2009 Washington DC
On July 4, 2009, BluFax was used to track vehicle and pedestrian traffic flows during 4th of July Independence Day special events along the 7th Street corridor. The density of traffic leaving the Mall made use of floating car studies impractical.
The data showed the influx of pedestrians before the beginning of the Independence Day celebrations, and the flood of pedestrians and vehicles at the conclusion. Travel time plots for segments close to the National Capital Mall (south end of the study area) show clear differentiations in travel times for pedestrians and vehicles. Tools included in BluSTATS allow specific traffic streams to be filtered (omitted) from travel time calculations.
Interchange studies. Intersection and interchange studies represent the simplest type of origin-destination study. As few as for sensors can be placed to obtain turning movement proportions for all twelve unique movements.
Freeway Corridor Origin-Destination Studies. BluSTATs provides the tools needed to support detailed analysis for each exit area, as well as generation of trip-tables for large study areas. As part of the analysis, users can also generate link travel time statistics, which provides added value for model validation.
Freeway-Arterial Corridor Studies. BluSTATs software supports development of trip tables, travel time matrices, and travel-time statistics for alternate routes that are tailored to the analysis requirements of each study.
High-density urban environments. Traffax transportation experts have worked with customers to collect and process high-quality data in the most challenging environments. Bluetooth antennas and BluFAX sensor operating parameters can be configured by users to optimize data collection in locations where intersections are closely spaced, congested conditions are common, and slow moving traffic streams include vehicles, pedestrians, bicycles, and transit lanes. BluSTATs Analysis Software allows users to specify processing parameters and filters, to focus on the traffic streams of interest, and the transparency during the analysis process needed to identify and address specifial processing requirements.