 The deployment of new GPRS real-time traffic monitoring systems is set to provide traffic engineers with valuable information for planning and infrastructure design, as well as traffic signal and enforcement applications
Representing a stepping stone toward third-generation wireless communications, the deployment of GPRS provides the means to create new services where a fixed telephony network infrastructure is neither available nor otherwise viable.
The HI-TRAC traffic counting, classifying and weigh-in-motion systems from TDC utilise GPRS packet-based communications, allowing vehicle traffic data to be transmitted and received across a mobile telephone network and the internet. This new development fulfils the requirements of both traffic planning departments (for statistical historical traffic data) and also other needs for real-time traffic data, such as a UTMC compliant common database.
GPS communication
The HI-TRAC traffic counters are programmed with the static IP address of the GPRS communication server that is connected to the internet. Every five minutes (or more frequently if required) the counters open a GPRS communication channel – through the mobile telephone service provider and internet – to the server. A status data packet is transmitted, including information on traffic events as well as diagnostics, such as battery and inroad sensor status. The server then takes control of the connection and requests vehicle data. The communication software and firmware has been developed by TDC in partnership with Drakewell Computers, which has over 20 years’ experience developing traffic software solutions. This real-time vehicle-by-vehicle data is stored by the communication server in the C2 database in a secure environment with UPS and generator redundancy. Connected via a high-speed data line to the internet backbone, the C2 web server provides a fast connection to C2 web reports for web-based analysis reporting. The data can be hosted and fully maintained by Drakewell, or alternatively the communications server can be leased and the data can be hosted by the client. Customers can also have unlimited nodes, sites and users. Each user can beassigned to a group and each group can have its own access rights and available reports.
Pioneering and proven
“We were one of the first authorities to employ the HI-TRAC GPRS-enabled counter classifiers,” explains Neill Bennett, senior traffic data officer at Derbyshire County Council in the UK. “The real benefit lies in the GPRS download of data, which is far superior to GSM communications. Data is sent automatically to our data-processing host without the need to check or interact with it. Hence there are savings to be made in terms of time, which will enable officers to devote more time to the analysis of the data rather than to its collection. “With the appropriate database login, the location of the monitoring site and the corresponding data can be made available to any one of my colleagues within the authority, and can easily be viewed or printed in the form of summary reports based on volume, speed and classification. We are looking to add a number of new sites to the network soon and are looking forward to analyzing the long-term benefits.” TDC has recently received several major orders to upgrade existing HI-TRAC EMU (Event Monitoring Unit) traffic-counting sites for GPRS connection. Customers that invested in the EMU as a result of its scalability are now being further rewarded by making use of this new functionality.
The HI-TRAC EMU is a low-power traffic data-collection system that can be configured for a variety of applications. It can be used as a loop-volumetric counter, a loop-speed and -length classifier, or a loop-profiling classifier. It can also be used for AVC with a bicycle and motorcycle classifier, as well as for weigh-in-motion and event monitoring. The unit incorporates interfaces to both Piezoelectric sensors, inductive loop sensors and road-installed temperature probes. Additional transducers include a wet/dry indicator that can be used to provide valuable traffic incident information.
The EMU can be powered from either mains supply or solar panel and associated battery and charge regulator. Depending on site location, a single 10W panel mounted on the roadside cabinet roof is sufficient to power the EMU autonomously, even with real-time telemetry activated. GPRS-enabled traffic counters can provide valuable information for traffic planning and infrastructure design, as well as real-time applications such as traffic signal control and enforcement. An added bonus is cost savings in the form of reduced telemetry bills, and manpower savings resulting from removing the headache of data collection. |
