Road transportation

Siemens is at work shaping the next generation of mobility – from the electric trolley bus to sensor-controlled parking management systems. 

1881: The "Elektromote"

In 1882, Werner von Siemens presented the world's first bus that ran from a power line suspended overhead – an invention that he had been working on for decades.


The vehicle, dubbed the "Elektromote," was supplied with electricity from an overhead wire, or “catenary.” A small, eight-wheeled "contact car" traveled along this double-pole cable, and served as a current pickup. Two copper cables connected the contact car to the vehicle, powering the two three-horsepower motors.


These gave the Elektromote an average speed of 12 kilometers per hour, at an operating voltage of about 550 volts DC. Although the trolley bus was more economical than rail vehicles, test runs were soon discontinued – mainly because the streets were simply too bad for it to run without constant disruptions.


Around 1900, engineer Max Schiemann went back to the idea, in collaboration with Siemens & Halske. Since the 1920s, trolleys running from an overhead catenary have become an important electric mode of transportation.

1924: Traffic light at Potsdamer Platz, Berlin

The first traffic signal system, running with gas light, was set up in London back in 1868. But it exploded shortly afterwards, killing a policeman. Not until 1914 was a traffic light installed once again, this time in the USA and using electric light. Siemens finally inaugurated Germany's first automated traffic control, at Potsdamer Platz in Berlin, in 1924. The signal lamps, aligned beside each other on a tower, were red, yellow and green.


The introduction of the light-emitting diode (LED) in the 1990s launched a new era in traffic light technology. LED signals need significantly less energy than conventional incandescent bulbs. And because LEDs have significantly longer service lives, they reduce operating and maintenance costs by eliminating the need for regular lamp replacements. Another advantage: modern LED optics offer maximum visibility in any weather, at any time of day or night.

1996: The diesel catalytic converter

Siemens joined together with car maker Uni Cardan in 1986 to found a joint venture named Emitec, intended to concentrate on building catalytic converters. The venture was a success. The Emitec heated metal catalytic converter, developed in 1992, reduced pollutant emissions effectively, even during the cold-start phase.


In 1996, Siemens introduced a special catalytic converter for diesel engines that reduced the polluting nitrogen oxide content of exhaust gases by as much as 95 percent. Siemens' SINOx exhaust-gas management system optimized exhaust gas treatment for diesel truck engines. Among its features, the catalyst module reduced nitrogen oxide emissions by about 70 percent and soot by up to 50 percent, so that diesel trucks could comply with even the most rigorous NOx emission requirements.


In 2001, Siemens researchers combined a plasma process with a catalytic converter to finally provide a solution for diesel passenger car engines, meeting even more stringent exhaust standards.

2000: World record piezoelectric diesel injector

In 1989, in response to the fast-growing role of electronics in cars, Siemens established a separate business unit for automotive technology. Besides individual components like air bags, ABS systems and navigation systems, the unit also made complete engine management systems. In 1992 it also began developing high-pressure diesel injection systems.


A key component of this "common rail" technology was the piezohydraulic injection valve, introduced in 2000. It had a switching time of 0.1 millisecond, a world record. The ability to measure out fuel very precisely brought a significant improvement in direct injection.


The "piezo" drive for injectors was five times faster than the conventional electromagnetic design. It generated enough lift and force to operate a valve, yet could also work at engine heats up to 150ºC, could be controlled at the voltages supplied by the on-board power network, and had the service life and reliability that were essential for passenger-car use.

2006: The Ruhrpilot intelligent traffic management system

In the Ruhr, Germany's largest megalopolis, some 1.1 million people commuted between cities by car every morning. Another five million drove in from the environs and the trend was rising. To control the region's heavy traffic, the Ruhrpilot traffic management system, developed by Siemens and several other partners, was introduced in 2006.


The Ruhrpilot continuously gathered electronic data about the traffic situation on freeways, highways and main town arteries. There were also another 200 measurement points in cities like Bochum, Dortmund, Essen and Gelsenkirchen. The traffic situation was then analyzed and the data were networked with data from other carriers like the railroad, local public transportation in eleven cities and four counties and 13 transportation companies. The result was up-to-date traffic information and projections for the whole urban region.


Travelers could pick the best route and get to their destinations faster. The system reduced accidents and traffic jams, avoided unnecessary energy consumption and cut CO2 emissions up to 20 percent.

2013: The world's biggest truck

The world's biggest truck in 2013 ran on electricity. Four Siemens electric engines, each at 1,200 kilowatts (around 1,800 horsepower), got the more than 800-metric-ton giant running. The first BelAZ 75710 was used at a mine in the Kuznetsk Basin of Siberia.


The truck was over 20 meters long, nearly 10 meters wide, and eight meters high. It weighed 360 metric tons empty, and could carry around 450 metric tons of cargo – about the same as a fully loaded Airbus A380.


The truck had a reliable, powerful all-wheel drive, with four electric engines. Electricity came from two generators, each driven by a 16-cylinder, 1,700-kilowatt diesel motor. The truck could carry a quarter more than the previous world's biggest dump truck, significantly reducing the cost per metric ton of the material carried. Empty, the truck had a maximum speed of 64 kilometers per hour. 

2015: Parking by radar in Berlin

In Berlin in 2015, Siemens launched a one-of-a-kind pilot project to simplify the search for parking. For testing and demonstration purposes, the company installed radar sensors on street lights that transmitted information about whether parking spaces were full or empty. The sensor network could scan within a radius of up to 30 meters around the street light – roughly the area of five to eight parking spaces. Drivers could then get information about available spaces even before they started their trip.

The city's traffic information center could use the information for its own services, or forward it to app operators and others via a data interface. So drivers could find out about available parking any time, via smartphone, GPS system or parking signage.

And the biggest attraction was that the software had an intelligent learning capability. The system could learn typical occupancy patterns from data provided by parking space sensors. So it could predict when and where the best chances for an open space might be. If no spaces were available locally, the system could suggest options for switching to public transportation in real time.