I'm in the Detroit area for the annual TRB/AUVSI Automated Vehicle Symposium, which starts tomorrow. Today, those in Ann Arbor attended the opening of the new test track at the University of Michigan. Instead, I was at a small event with a lot of good folks in downtown Detroit, sponsored by SAFE which is looking to wean the USA off oil.

Much was discussed, but a particularly interesting idea was just how close we are getting to something I had put further in the future -- robocars that are cheaper than ordinary cars.

Most public discussion of robocars has depicted them as costing much more than regular cars. That's because the cars built to date have been standard cars modified by placing expensive computers and sensors on them. Many cars use the $75,000 Velodyne Lidar and the similarly priced Applanix IMU/GPS, and most forecasts and polls have imagined the first self-driving cars as essentially a Mercedes with $10,000 added to the price tag to make it self driving. After all, that's how things like Adaptive Cruise Control and the like are sold.

Google is showing us an interesting vision with their 3rd generation buggy-style car. That car has no steering wheel, brakes or gas pedal, and it is electric and small. It's a car aimed at "Mobility on Demand."

When people have asked me "how much extra will these cars cost," my usual answer has been that while the cars might cost more, they will be available for use by the mile, where they can cost less per mile than owning a car does today -- ie. that overall it will be cheaper. That's in part because of the savings from sharing, and having vehicles go more miles in their lifetime. More miles in the life of a car at the same cost means a lower cost per mile, even if the car costs a little more.

The sensors cost money, but that cost is already in serious decline. We're just a few years away from $250 Lidars and even cheaper radar. Cameras are already cheap, and there are super cheap IMUs and GPSs already getting near the quality we need. Computers of course get cheaper every year.

This means we are not too far when the cost of the sensors is less than the money saved by what you take out of the car. After all, having a steering wheel, gas and brakes costs money. Side mirrors cost money (ever had to replace them?) That fancy dashboard with all its displays and controls costs a lot of money, but almost everything it does in a robocar can be done by your tablet.

That said, you need a few extra things in your robocar. You need two steering motors and two braking systems. You need some more short range sensors and a cell phone radio. But there's even more you can save, especially with time.

Because mobility on demand means you can make cars that are never used for anything but short urban trips (the majority of trips, as it turns out) you can save a lot more money on those cars. These cars need not be large or fast. They don't need acceleration. They won't ever go on the highway so they don't need to be safe at 60mph. Electric drive, as we discussed earlier, is great for these cars, and electric cars have far fewer parts than gasoline ones. Today, their batteries are too expensive, but everything else in the car is cheaper, so if you solve the battery cost using the methods I outlined Saturday we're saving serious money. And small one or two person cars are inherently cheaper to boot.

Of course, you need to make highway cars, and long-range 4WD SUVs to take people skiing. But these only need be a fraction of the cars, and people who use a mix of cars will see a big saving.

For a long time, we've talked about some day also removing many of the expensive safety systems from cars. When the roads become filled with robocars, you can start talking about having so few accidents you don't need all the safety systems, or the 1/3 of vehicle weight that is attributable to passive safety. That day is still far away, though cars like the Edison2 Very-Light-Car have done amazing things even while meeting today's crash tests. Companies like Zoox and other startups have pushed visions of completely redesigned cars, some of them at lower cost for a while. But this seems like it might become true sooner rather than later.

Evacuation in a hurricane

One participant asked how, if we only had 1/9th as many cars (as some people forecast, I suspect it's closer to 1/4) we would evacuate sections of Florida or similar places when a hurricane is coming. I think the answer is a very positive one -- simply enforce car pooling / ride sharing in the evacuation. While there is not a lot I think policymakers should do at this time, some simple mandates could help a lot in this arena. While people would not be able to haul as much personal property, it is very likely there would be more than enough seats available in robocars to evacuate a large population quickly if you fill all the seats in cars going out. Further, those cars can go back in to get more people if need be.

Filling those seats would actually get everybody out faster, because there would be far less traffic congestion and the roads would carry far more people per hour. In fact, that's such a good idea it could even be implemented today. When there's an evacuation, require all to use an app to register when they are almost ready to leave. If you have spare seats, you could not leave (within reason) until you picked up neighbours and filled the seats. With super-carpooling, everybody would get out very fast on much less congested roads. Those crossing the checkpoint on the way out with empty seats would be photographed and ticketed unless the app allowed them to leave like that, or the app records that it tried to reach the server and failed, or other mitigating circumstances. (This is all hours before the storm, of course, before there is panic, when people will do whatever they can.) Some storms might be so bad the cars are at risk. In that case, if the road capacity is enough, people could move out all the cars too, to protect them. But in most cases, it's the people that are the priority.

More tomorrow as the conference gets underway.