Development activities for the City of York (UTMC 29D initiative)
The City of York Traffic Congestion Management System Project was launched in 2001, as part of the DfT's UTMC initiative demonstrator projects Peek were selected as the UTC technology supplier Other partners on the project included Tenet (common database), IDT (cap parking outstations) and ACIS (RTPI).
Since the initial project launch, the core project team and the various technology providers, have worked together closely to enable the project aims to be developed and enhanced These developments have resulted in the delivery of a system, which enables the public to make better-informed choices on travel modes and routes as well as delivering real improvements to air quality.
By participating in an open and inclusive forum, Peek has been able to provide significant input into the initial system architecture and communications strategy for the UTC system. Continued involvement and close working with all the stakeholders, in the spirit of shared technical input, by all parties involved, has helped ensure that the initial aims and future ambitions of the City Council are met.
System activities to date
As part of the project design and development, Peek has incorporated dial-up adaptive UTC using SCOOT in conjunction with their IP addressable outstation, the I-OUT This has enabled a move away from second-by-second communications with no requirement for reliance on leased lines. The outstation, allows the City Council to choose between a range of available communications to select the option which delivers the operational requirements whilst offering the best value in terms of operating costs.
The outstation can be configured to run proprietary protocols for Keyline 3 circuits or IP based communications methods. As an IP enabled device, the outstation provides the maximum degree of flexibility and future proofing and will also take advantage of other wireless based communications while working along side the traditional OTU network.
As part of the connectivity from SCOOT to the I-OUT, a number of bearer media were planned to enhance system flexibility such as direct CAT-5 link and DSL. GPRS has been on trial for over a year and work is currently underway to implement GPRS between the SCOOT system and l-OUTs using GPRS. These alternate communications media are expected to deliver revenue savings over fixed line pstn and will allow remote monitoring and control at traffic signal locations where the installation of the fixed link is not viable.
Various types of industry standard communications technology have been trialled:
- All outstation equipment is controlled using SNMP; this allows any form of IP capable media to be used GPRS is now being widely used to reduce line installation and lease costs.
- DSL have been deployed and worked very reliably for a number of applications providing a very cost effective solution.
- 802.11 b/g wireless LAN has proved to be a robust and reliable means to connect equipment to remote communication hubs.
Communication standards that have been trialled and deployed to-date include:
- ISDN Peek provided ISDN communications to 3 controllers, which form part of the UTMC infrastructure on an ongoing basis.
- DSL and Wi-Fi One controller has been implemented at the Rulecliff bar car park, incorporating both DSL and Wi-Fi, which has been running on an ongoing basis for 3 5 years.
- GPRS Survey results for the 3 controllers using GPRS communications (ongoing for over a year) show that the communications using SNMP are acceptably low in bandwidth, making this a viable medium especially for part-time control during periods of communications congestion.
- Cat-5 One controller which is situated within 500 meters of the in-station has been directly connected using Cat-5. This has formed a successful part of the network for over a year.
Initial communications trial
As part of each trial the analysis of the captured data highlighted properties common to each OTU as follows (An SNMP message was generated when one of the following bits changed, rather than every second):
- Force bits
- Demand bits
- Green confirm bits
- Detector reply bits
Communications between the in-station and I-OUT are demand dependent and approximately 30% of messages are initiated by the In-station which mainly consist of Force/Demand bits. The remainder of the messages sent is initiated by the I-OUT and are Green confirm and Detector reply bits. The bandwidth requirements are fairly low with each message using approximately 180 bytes (including acknowledgement) and messages are sent approximately every 8 seconds. The study was unable to highlight the timeliness of delivery of messages, other than it was observed that messages were responded to within the same second.
The conclusion of each of these trials has indicated that the I-OUT has consistently given prompt delivery of messages throughout the trial on an ongoing basis. The SCOOT detection bits were confirmed as having an additional 180 bytes of data transferred per second and no missed packets or packets which arrived out of sequence were recorded during the initial trials.
Wireless communication between the controller outstation and VMS signs has been successfully demonstrated in the recent York UTMC29 project. This project has clearly shown the benefits of using digital devices to share communication capacity and thereby reduce the overall communication costs.
The I-OUT (intelligent Outstation), digital outstation is centred on a powerful single board PC, with a modem or network adapter fitted as applicable. The unit is compatible with standard detectors, logic modules and lamp monitoring units, all of which may be fitted into its standard 3U 19" sub-rack.
Today, Peek continue to work closely with the core project team to ensure that the system continues to take advantage of technology advancements and continues to deliver real improvements to the residents and visitors to the City of York.
The next generation of digital outstation device is now being developed on the strength of lessons learnt in to UTMC 29 York demonstrator project. This will become Peek's standard UTMC outstation device, and will be marketed as the Chameleon. Field trials are currently ongoing, and the product is expected to be fully launched in March 2006.