Sitraffic: a key component of a traffic management control center

Developed not only to guide car drivers to unoccupied parking spaces in a city but also to be used as an integral part of a traffic management control center, the Sitraffic Guide dynamic parking guidance system from Siemens Mobility is unique in that it can be used to implement urban traffic strategies. Promoting better utilization of available parking spaces – thereby helping to reduce the traffic volume and environmental impact – Siemens believes this is what ultimately makes a city more attractive as well.

As much as 40% of inner-city traffic consists of vehicles looking for somewhere to park. During peak periods, this increases substantially and leads to the congestion of city streets. However, if information on free parking spaces is made available at strategic points in the city, the number of vehicles searching for a place to park drops sharply. Dynamic message signs set up in the driver’s general field of vision provide information on the current occupancy levels of individual parking areas and guiding him along the shortest route to his final parking destination.

Sitraffic Guide provides the user with several different control algorithms for the focused control of traffic looking for available parking spaces. This control can be based on the current occupancy data of all parking facilities. The parking guidance signs display the number of spaces currently remaining in each multi-storey parking lot. But guidance can also make use of predictive calculations, in which case parking guidance signs show the foreseeable occupancy level based on the travel time between the parking sign and the assigned multi-storey parking lot, as well as on the historical occupancy curve depending on the time of day.

Another possible strategy is to combine different areas to form one parking zone. In order to display the occupancy data for these parking areas together, special parking guidance signs are placed at strategically favorable points within the confines of the city. The parking guidance signs indicate the current number of remaining parking spaces in several multi-storey parking lots belonging to a single logically integral parking zone. As an emergency strategy, control can also be based on substitute data. The parking guidance signs then show the occupancy level on the basis of historical values that depend on the time of day and adjust themselves automatically. This form of control comes into effect if communication with one or several multi-storey parking lots is interrupted, for example.

Previously, parking guidance systems were mostly operated as isolated, standalone systems. However, communities are now requiring that such systems be deployed as part of an overall traffic management system. Sitraffic Guide is an easy-to-integrate component of the Sitraffic family of systems from Siemens Mobility and can be expanded step by step to create a comprehensive traffic management system. For example, communities can supplement the system with additional modules such as a traffic computer center, a freeway management system, automatic traffic incident detection or video monitoring in order to implement diverse harmonized strategies. Parking guidance therefore becomes part of a holistic traffic-optimization process.

Sitraffic Guide has a graphic user-interface, meaning that the operator can view the entire occupancy and utilization situation in a clear and easily comprehensible form and – if desired – can also intervene manually from a central location. A certain number of parking spaces can therefore be reserved, or control of the signs can be adapted to parking lot opening times. On top of all this, there are tools for statistical evaluations and the generation of system reports. For link-up to external systems, Sitraffic Guide supports the standardized OCPI (Open Content Provider Interface) system interface. This makes it possible to transfer car park occupancy data to a web server or import occupancy data from external multi-storey parking lot systems.

The parking guidance system also allows the incorporation of parking guidance signs. In addition to a numerical display, text-based or graphic-based displays can be integrated. Due to the modular design of its system architecture, Sitraffic Guide can be aligned to specific customer requirements. With the parking guidance system from Siemens Mobility, communities can start with a small to medium-sized parking scenario and then expand to create a large and even cross-regional parking guidance apparatus.
 

17 June 2009