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BMW and Siemens Car2X System Transmits Data Between Traffic Lights and Vehicles to Optimize Stop-Start Function

During the AASHTO conference (American Association of State Highway and Transportation Officials) in Palm Desert, California last fall, BMW and Siemens presented a system that transmits data between traffic lights and the vehicle to optimize the automatic engine start-stop function and the recovery of braking energy when approaching a traffic light.

Current vehicles use sensors to constantly gather information about such things as speed, the environment, or the traffic ahead. Networking the cars makes it possible to warn the vehicles behind about icy roads, traffic jams, or similar situations. Intersections and multilane roads will become safer if the cars all keep an eye on one another. Energy efficiency also improves. Fuel consumption can be reduced even further if the automatic engine stop-start system from BMW EfficientDynamics knows the traffic signal cycles.

The function presently switches the engine off as soon as the car is stationary and the driver releases the clutch, with the engine restarting when the clutch is depressed. If there are only a few seconds between stopping and starting, however, it is more energy efficient to let the engine run.

At the same time, vehicles could send back information to the traffic light, e.g. position, direction and speed of the car, which can be used to optimize the traffic flow and to adapt the cycle time of the traffic light.

The improved networking of cars among themselves and with traffic lights or warning signs is expected to make road traffic more efficient. The exchange of data on traffic density, road conditions, or traffic signal cycle times enables traffic to flow more freely and also makes it safer.

This information is particularly important for optimal energy management in electric cars. With Car2X communication, vehicles communicate either with other vehicles (Car2Car) or with the traffic infrastructure (Car2Infrastructure).

Car2X communication also turns cars into mobile sensors for traffic management systems because they provide up-to-the-second data about the traffic situation.

Among the things under development by Siemens Corporate Technology (CT) are efficient communication protocols with which the data can be transmitted within just a few milliseconds to all partners in the surrounding area. The company is also working within the Car2Car Communication Consortium to develop standards that ensure that all makes of cars and the infrastructures can “talk” with one another without problems. Siemens is also developing prototypes of the communication units.

Siemens is currently the only company that can offer integrated solutions for both vehicles and traffic infrastructures.



I don't know. Something doesn't seem quite right about this. Too much loss of personal control on the individual's side. People are pretty stupid as it is, this just gives them an excuse to get stupider.
I understand the reasons behind the concept - "Make driving safer" - but it leaves open a lot of room for abuse. All this information would naturally flow through some kind of communications center. All you would then need is one guy who's pissed at the world and decides to run the wrong data back through the system and causes all traffic, everywhere, to stop. Or worse, keep going.
Just a thought...


Smarter intersections make sense if safeguards are in place. I think telling your PHEV/EV where you intend to go can help the computer plan the best charging strategy. If you are going less than 10 miles around town it is one mode, if you are commuting 40 miles each way, it is another.


Too much loss of control? When the car is shutting its own engine off, you're worried about it getting timing info from the traffic light?

Know what would really cause "loss of control", and improve matters immensely? Automated acceleration away from lights and control of traffic which can't make it so that it doesn't waste fuel coming up to speed. Too many drivers aren't competent to follow the car in front very closely. If everybody's radar cruise control could operate at a distance of feet and was set to accelerate just a bit slower than the car in front, many more vehicles could get through each green light without any greater use of fuel. Data from the traffic light could tell cars if they had time to get through the green or not, and braking could be automatic. The driver would only have to steer. Feedback could be through the accelerator pedal. The increase in traffic flow would slash congestion.

Abandoning a lot of personal control could wind up saving the personal automobile, but I suspect that some people would still resist it.


Just the wasted time, fuel and pollution created from poorly timed traffic lights calculated across the U.S. is immense. I would like to see GPS and mapping of routes so that we can make personal transportation more efficient and less frustrating.

If I can tell my car where I want to go and it can figure the best time and route to save me fuel and time I would love it. People in L.A. can spend an hour just getting down to the market and back a few miles away after work. Freeways are parking lots and when you get there, there is no place to park anyway.

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