Overview
Poznan - the capital and largest city of the Poznan province, lies on the Warta River in west-central Poland with around 700 thousand inhabitants. The city is a major cultural, industrial, commercial and literary centre. Industries including metallurgical works, chemical and furniture factories, textile mills, and food-processing plants.
The city is located at the intersection of the busy highways between Berlin - Warsaw and Gdansk - Wroclaw which run through the heart of the city leading to particularly high levels of traffic in general and heavy goods vehicles in particular.
As in many larger cities in Central Europe, traffic in Poznan has been growing rapidly since the move to a market economy. Current infrastructure, both road networks and traffic control elements were designed for a different level of traffic flows. In the face of low investment funds available to build a necessary ring-road, the power to regulate traffic and optimise flow is essential to prevent chronic congestion and pollution problems in the centre of the city. The CITYMAN Poznan project arose against this background. With the aim to help solve this problem, a consortium including a leading Dutch supplier and the Polish consultancy firm PolTraffic in 1996 applied for and gained 1 million EUR of support for a traffic management project from the Dutch Government through the international EUREKA programme.
Within the project, the consortium defined and developed a signal controller upgrade plan for a pilot area of Poznan including the main arterial road. This included the development of a generic (single board computer) black box device, which locks on to and takes over the control function of the existing controller, enabling traffic responsive control, central control and network optimisation. A high level library of control functions was also adapted to local conditions and regulations, thus enabling the fast creation of easily adaptable controller software with advanced dynamic functionality.
3 main installations were tested and implemented in a pilot setting. Preliminary measurements showed a 30% increase in capacity of the artery.
The result of the project was the fulfilling of the stated objectives, satisfaction on all sides and commercial continuation of the project, Poznan has ordered over 40 more black boxes. The project is a good example of public-private co-operation, where challenges were met through a combination of professionally and commercially motivated commitment.
The research and development aims of the project were defined thus:
- Upgrade and integrate the installed base of "legacy" intersection controllers (for a section of the City). The aim was to change existing controllers from rigid non-traffic responsive into traffic responsive controllers with a capability to become integrated into a traffic management and control network.
- Adapt a generic control programme, which is universally applicable in order to avoid dedicated development for each specific intersection.
- Introduce a central management system on the basis of the proven Nederland Haarlem CityMan concept.
- Introduce alternative detection methods (such as camera based) where it proved expensive or ineffective to install classical loop hole detection.
- Achieve optimisation both at a central network and a local intersection level (2 tier optimisation).
The pilot project was implemented for the upgrade of 10 existing controllers and 5 new controllers were applied on one of the main arteries of Poznan. The above targets were met and the project is moving forward on a commercial basis. The city has ordered over 40 controllers to be upgraded and the fruitful relationship between the Dutch supplier, PolTraffic and the City of Poznan continued to grow healthily.
Technical profile of project
Three main installations were tested and implemented in a pilot setting:
- 10 Polish legacy controllers were upgraded into intelligent traffic responsive and network integrated controllers and 3 new traffic responsive controllers were installed on the main Remonta artery road;
- At the Most Teatralny intersection, a new traffic responsive controller with complex tram priority system;
- A new traffic responsive controller using Autoscope video detection for the Roando Kaponiera intersection.
The following research and development tasks were accomplished :
1. Upgrading and integrating the installed base of "legacy" intersection controllers
This upgrade was made by creating a generic black box single-board computer for each legacy controller, which took over the traffic control function while leaving intact the original shell (although allowing for other inputs such as video detector data). Ensuring a reliable communication between the black box and the legacy controller was crucial to the success of this upgrade. It was achieved by :
- creating a generic "master" protocol in the black box which should be able to communicate in principle with any type of legacy controller.
- persuading the manufacturer of the legacy controller to develop a "slave" protocol adaptation of his controller conforming to the "master" protocol specification and therefore connecting his device with the black box.
2. Adaption of a generic control system which is universally applicable
This involved the application and adaptation of a library of high level generic routines, which are used to "build" controller software for the black box device. The library has over 150 functions and enables very fast construction and adaptation of advanced controller logic. The routines were adapted here for Polish peculiarities such as special tram signals and PT priority and static right turn gree
Funding
Results
All parties concerened in the project are satisfied with the results of the project and all technical objectives have been met. The proof of the success, given the objectives of the EUREKA programme in promoting industrial R&D co-operation which leads to commercial follow-ups, lies in the response of the city, which has ordered a further 43 black box devices to be integrated into the central control system.
Preliminary measurements show a 30% increase in capacity on the main artery of Poznan. It is not clear what the impact of optimisation of this main artery had on the capacity of conflicting flows.
Barriers and Conflicts
The main technical obstacles were met in adapting state of the art technology to existing hardware and local conditions. Traffic conditions and traffic in Poland differ widely from the conditions generally met in countries of the EU. The biggest challenge was to build a truly open system, which could in principal communicate with any existing controllers in the country. The team, however, succeeded in overcoming the majority of challenges that they met.
The biggest implementation problems were met with the Autoscope video detection system. Although the system proved to be a reliable and acceptable substitute for buried loop detectors in dry testing, when installed in situ in June 1998 it was prevented from working reliably by the movement of the poles to which the cameras were attached (the poles support the overhead power supply for trams). Video detectors are extremely sensitive to movement and changes of lighting etc. and therefore special and delicate system tuning are often necessary. The supplier of the video detection technology is working on the problem.
Transferability
The project was practically all about transferring state of the art signal control technology at minimum cost into an environment with basic but not complete detection and control infrastructure. The products were made generic and therefore transferable in the first instance to the rest of Poznan, in the second instance to the rest of Poland and then to other cities anywhere of similar scale and with similar needs.
The project shows quite clearly that transferability is a big issue from both a technical and financial viewpoint. Without the development of a black box device, it is unlikely that Poznan could have made such quick progress in upgrading to a traffic responsive, centrally connected