Expressways

The core of this urban highway solution consists of the Siemens SITAFFIC CONDUCT+ international highway control center – which integrates different urban highway subsystems, also exchanging relevant traffic and environment data with other urban management systems.

The subsystem applications range from classic traffic management on main routes – with traffic regulation and information transfer – to traffic control at interchanges, up to ramp metering. In addition, numerous external systems such as tunnels, video surveillance, emergency call systems, toll systems, and travel weather information systems can be integrated step by step into the urban highway system. Depending on market requirements, urban highway subsystems can be used individually or in various combinations.

SITRAFFIC CONDUCT+ is the further development of our proven control center on a new platform. It ensures safe, effective, and uninterrupted operation in both long-distance and urban highway networks.The CONDUCT+ control center receives all information on network utilization and the condition of all operating facilities. Sensors deliver data on traffic and ambient conditions – the control center applies defined strategies and rules to determine the appropriate measures to harmonize traffic.

The system is highly standardized and based on proven client/server technology. It uses Microsoft Windows or Linux operating systems, and is expandable at any time and in any direction. This means that it maintains its value over a long period of time – and that expensive overdimensioned systems are no longer necessary. The center grows with its functions, module by module, and is simply expanded when a new tech-nical system is added – such as access control or shoulder release for traffic. SITRAFFIC CONDUCT+ has a second server that keeps running in "hot standby" mode. If the active server is experiencing problems, operations are switched to the other server automatically, for maximum availability.

Sensors measure factors that provide information
about current conditions – including brightness,
traffic volume, and weather conditions. This data
is vital for automatic traffic management.

Siemens sensors provide current, precise data on the
following factors:

• Visibility
  The visibility sensor identifies low visibility conditions caused by fog or snow, and transmits the visibility data to the higher control center.
• Environment Sensors
  Data such as air temperature, wind direction, and wind speed – as well as type and intensity of precipitation, road surface temperature, residual salt content, etc. – are documented by a weather and environmental-data station.
• Brightness Sensors
  Brightness sensors are used to adjust the lighting level of the variable message signs. The very high light intensity of the VMS ensures good daytime visibility even when the sun is low. At night, the VWS are dimmed so that motorists are not impeded by glare and the symbols are not too bright.
• Loop Detectors
  Loop detectors provide all necessary statistical data. The loop detectors classify the vehicles into classes (up to 8+1). All loops are doubled so that they can determine not only the number and type of vehicles, but also their speed and direction.
• Above Ground Detectors (AGD)
  AGDs can be installed instead of loop detectors to provide the same types of data. Due to recent developments, AGDs are almost as accurate as loop detectors, but are considerably faster to install.

Actuators react to changes in conditions and
adapt to new situations by informing motorists
of the current conditions – either automatically
or manually. This, in turn, facilitates safe and
smooth traffic flows.

The comprehensive Siemens portfolio includes
the following actuators:

• Variable Message Signs, Speed Limit Signs
  Variable message and speed limit signs (VMS and SLS) use LEDs to display text information or traffic symbols. The LED elements are monitored by their control unit to prevent disrupted, illegible, or contradictory displays. An optional hardware lockout can also be installed.
• Lane Control Signs (LCS)
  Lane Control Signs use LEDs to display lane signals with arrows. The display elements are monitored to prevent unsafe signaling states. An optional hardware lockout can also be installed.
• Lane Lights
  LED lane lights are set into the roadway surface, and can be used either for dynamic lane assignment or static shoulder marking.

Depending on market requirements, urban highway subsystems can be used individually or in various combinations. Optional components for automatic monitoring of traffic flows can boost through-travel capacity, improving safety and reducing pollution.

The following components can be added:

• Main Lane Control System
  Automatic monitoring of the traffic flow, with the ability to react in dangerous situations by applying speed limits or closing a lane.
• Network Influencing
  Recommendations for alternative routes can be made in order to decrease travel time and increase capacity throughout the highway network.
• Alternative Route System
  Automatic monitoring of traffic flows on the normal route and the alternative route compares their traffic volumes and makes route recommendations on displays.
• Traffic Information System
  Balancing of traffic volumes on alternative highway routes by informing motorists of the traffic situation and alternative routes.
• Ramp Control System
  Automatic control of traffic flow on entry ramps by reducing the number of vehicles in the main lane.
• Shoulder Lane Control System
  Increasing the flow of traffic by allowing use of the shoulder lane, to minimize the risk of congestion and increase safety during periods of high traffic density.
• Traffic Data Acquisition System
  Capture, analysis, and monitoring of traffic data, situations, and events for controlling the flow of traffic (manually or automatically), with subsequent archiving in the CONDUCT+ highway central control system).

The SST4 roadside controller family is based on the existing TLS 2002, and comes pre-equipped to meet the requirements of the German Highway Research Institute (BASt). The future-proof PC104 standard, numerous communication interfaces, and the easy-to-maintain design are furnished as standard equipment. The SST4 offers plenty of room for expansion for elements such as GPRS, Ethernet, up to 20 loop detectors, FSK modem, and USV.

The SST4-XS is the "light" version – perfect for simpler applications such as a data collection tool, Inselbus communication computer, speed warning system, input/output concentrator, and more.

By using different installation frames with selected components, it is easy to create project-specific solutions tailored to the needs of the individual client – whether this involves the installation of the components into existing cabinets or into WMS (Variable Message Sign) housings, receded detector stations with solar power, or license-free radio connection.

With the ComBox from Siemens TS, the customer gets an "Inselbus Communication Computer" compliant with TLS specifications (German Highway Research Institute – BASt), offering a broad range of practical applications.

The ComBox has good computing performance and can manage up to 13 TLS inselbuses. It communicates with the subcenter by TLS or TLS over IP. It can be in contact with a large number of external systems in various ways (such as by radio or serially), and can provide compressed user data to various subcenters.

Thanks to many software tools used in conjunction with other Siemens checkpoint components, the ComBox is extremely service-friendly.