US push to mandate V2V radios -- is it a good choice?
Submitted by brad on Mon, 2014-02-17 10:06It was revealed earlier this month that NHTSA wishes to mandate vehicle to vehicle radios in all cars. I have written extensively on the issues around this and regular readers will know I am a skeptic of this plan. This is not to say that I don't think that V2V would not be useful for robocars and regular cars. Rather, I believe that its benefits are marginal when it comes to the real problems, and for the amount of money that must be spent, there are better ways to spend it. In addition, I think that similar technology can and will evolve organically, without a government mandate, or with a very minimal one. Indeed, I think that technology produced without a mandate or pre-set standards will actually be superior, cheaper and be deployed far more quickly than the proposed approach.
The new radio protocol, known as DSRC, is a point-to-point wifi style radio protocol for cars and roadside equipment. There are many applications. Some are "V2V" which means cars report what they are doing to other cars. This includes reporting one's position tracklog and speed, as well as events like hitting the brakes or flashing a turn signal. Cars can use this to track where other cars are, and warn of potential collisions, even with cars you can't see directly. Infrastructure can use it to measure traffic.
The second class of applications are "V2I" which means a car talks to the road. This can be used to know traffic light states and timings, get warnings of construction zones and hazards, implement tolling and congestion charging, and measure traffic.
This will be accomplished by installing a V2V module in every new car which includes the radio, a connection to car information and GPS data. This needs to be tamper-proof, sealed equipment and must have digital certificates to prove to other cars it is authentic and generated only by authorized equipment.
Robocars will of course use it. Any extra data is good, and the cost of integrating this into a robocar is comparatively small. The questions revolve around its use in ordinary cars. Robocars, however, can never rely on it. They must be be fully safe enough based on just their sensors, since you can't expect every car, child or deer to have a transponder, ever.
One issue of concern is the timeline for this technology, which will look something like this:
- If they're lucky, NHTSA will get this mandate in 2015, and stop the FCC from reclaiming the currently allocated spectrum.
- Car designers will start designing the tech into new models, however they will not ship until the 2019 or 2020 model years.
- By 2022, the 2015 designed technology will be seriously obsolete, and new standards will be written, which will ship in 2027.
- New cars will come equipped with the technology. About 12 million new cars are sold per year.
- By 2030, about half of all cars have the technology, and so it works in 25% of accidents. 3/4 of those will have the obsolete 2015 technology or need a field-upgrade. The rest will have soon to be obsolete 2022 technology. Most cars also have forward collision warning by this point, so V2V is only providing extra information in a tiny fraction of the 25% of accidents.
- By 2040 almost all cars have the technology, though most will have older versions. Still, 5-10% of cars do not have the technology unless a mandate demands retrofit. Some cars have the equipment but it is broken.
Because of the quadratic network effect, in 2030 when half of cars have the technology, only 25% of car interactions will be make use of it, since both cars must have it. (The number is, to be fair, somewhat higher as new cars drive more than old cars.)