Brad Ideas

Robocars & More

I've written a few times about the "Selfish Merge" problem. Recently, reading the new book Traffic: Why We Drive the Way We Do by Tom Vanderbilt, I came upon some new research that has changed and refined my thinking.

The selfish merge problem occurs when two lanes reduce to one. Typically, most people try to be "good" and merge early, and that leaves the right lane, which is ending, mostly vacant. So some people zoom ahead of everybody in the right lane, and then merge at the very end. This is selfish in the sense that butting into any line is selfish. Even if overall traffic flow is not reduced (and even if it is increased) the person butting in moves everybody back one slot so they can get ahead by many slots. This angers people and generates more counter-productive behaviour, including road rage, and attempts to straddle the lanes so that the selfish mergers can't move up to the merge point.

In Traffic, Vanderbilt writes of surprising research that changed his mind, which showed that, in simulations, some merging forms provided up to 15% more traffic throughput than proper attempts at a zipper merge. In particular, a non-selfish merge fully using the vanishing lane worked better than the typical butt-in situation described at the top.

In this merge, which I'll call the "slow and fair merge," drivers are told to use both lanes up to the merge-point, and then to fairly "take their turn" at the merge point entering the continuing lane. Nobody is selfish here, in that nobody butts ahead of anybody else, but both lanes are fully utilized up to the merge point.

This problem is complex, I believe, because there is a switch-over point, which I call the "collapse" point. This is the point at which the merge flow becomes high enough that traffic collapses to "stop and go" mode, before and at the merge-point. Before that point, in lighter traffic, there is little doubt (for reasons you will see below) that the "cooperating fast zipper" merge results in the best traffic flow. In particular, there are traffic volumes where you could either have cooperating zipper or "slow and fair" but cooperating zipper would do a fair bit better. There are also traffic volumes where cooperating zipper just isn't possible any more, and we will either have "slow and fair" (which has the best volume) or "selfish merge" which has a worse volume.

Real world experiments show different results from the theoretical. In particular, many drivers, used to the anarchic selfish-merge approach, don't understand fair and slow, even when signs are explicit about it, and so they resist using both lanes and try to merge early. They also try to straddle, devolving to selfish merge. An experiment with digital signs which changed from advising drivers to zipper-merge in light traffic to advising "use both lanes" and "merge here, take your turn" in heavier traffic was disobeyed in fair and slow mode by too many drivers. The experiment ended before people could learn the system.

This week, as part of a 3-part series on the future of driving, ARS Technica has written a feature article derived from, and covering my series on Robocars. While it covers less than I do here, it does present it from a different perspective that you may find of interest.

I have tripods with both 3 segments and 4 segments. A 4-segment tripod has 3 clamps per leg, which means 9 of them to open and close in extending and collapsing the tripod. That's a pain. Enough of one that you sometimes find yourself asking whether a shot is worth setting up the tripod. But even 3 segment tripods are only a bit better.

Some upcoming events I will be involved in:

Burning Man Decompression, Sunday Oct 12

As I have for the past several years, I will show off my newest giant photographs of Burning Man at the "decompression" party, which takes place from noon to midnight on Sunday, Oct 12 (this coming Sunday) on Indiana St. south of Mariposa in San Francisco.

Ford is making a new car-limiting system called MyKey standard in future models. This allows the car owner to enable various limits and permissions on the keys they give to their teen-agers. Limits included in the current system include an 80 mph speed limit, a 40% volume limit on the stereo, never-ending seatbelt reminders, earlier low-fuel warnings, audio speed alerts and inability to disable various safety systems.

The worst thing about political debates occurs when the candidates break into their canned speeches, often repeating ones they had done before, and often when they have very little to do with the question that was asked. This happens because the candidates' teams, in negotiating debate rules, want it to happen. They want a boring debate, because they know that while it's hard (but not impossible) to win an election with a great debate performance, it is certainly easy to lose one with a bad one. So they avoid risks.

Coming up in a couple of weeks I will be speaking as a special guest at Alternative Party, a digital culture conference in Helsinki, Finland. I'll be doing my main talk on October 25th plus an extra session on either the 24th or 26th depending on schedules.

After that I will head to do some touristing in Stockholm for a few days, then for my first trip to Russia to visit St. Petersburg on the 31st.

Have some recommendations in Stockholm or St. Petersburg area? Let me know. My hosts will take care of me in Finland.

I've added a new Robocars article, this time expanding on ideas about how parking works in the world of robocars. The main conclusion is that parking ceases to be an issue, even in fairly parking sparse cities, because robocars can do so many things to increase, and balance capaacity.

Most of us have had to stand in a long will-call line to pick up tickets. We probably even paid a ticket "service fee" for the privilege. Some places are helping by having online printable tickets with a bar code. However, that requires that they have networked bar code readers at the gate which can detect things like duplicate bar codes, and people seem to rather have giant lines and many staff rather than get such machines.

Can we do it better?

Readers of this blog will know I used to talk a bit about Personal Rapid Transit (PRT) but have switched to a belief that it is now likely that robocars might fulfill the PRT vision before actual PRT can. To understand that, it is necessary to explore just why PRT has never really come about, in spite of being promoted, and possible for almost 40 years.

A friend (Larry P.) suggested that the time was here for serious (ie. DSLR) cameras to undertake a design revolution. The old SLR design, with a mirror that flips up and must sit between the last lens element and the sensor, creates a lot of problems in designing the lens and camera systems. Yes, being able to view directly through the lens with your eye is a very useful thing. But at what cost?

As a Canadian, and one of libertarian bent, I hope I have a better perspective on the two parties in the USA. What I see does not bode well for the Democrats. I think they understand the Republican side poorly, worse than the Republicans understand them. And, over the last two elections, they have shown little willingness to learn about it.

The law is full of defaults, as it is supposed to be. Some are in statutes, some are the result of many years of history of common law. They define the duties that people have in many ordinary transactions.

In my previous post, I noted that I had not done many night panoramas of Burning Man. I thought I should outline just why they are such a challenge.

Back from Burning Man and still dusty, here are five large panoramas to give you a sense of it.

It's amazing how much preparation is required for Burning Man. Or at least if you are crazy like me and plan to spend 11 days there, have 4 art projects, manage a new camp and still survive.

NBC has had just a touch of coverage of Michael Phelps and his 8 gold medals, which in breaking Mark Spitz's 7 from 1972 has him declared the greatest Olympic athlete, or even athlete of all time. And there's no doubt he's one of the greatest swimmers of all time and this is an incredible accomplishment. Couch potato that I am, I can hardly criticise him.

Photographers constantly debate about jpeg. Should they shoot in RAW or JPEG, for example. RAW preserves everything, but is much harder and bulkier to work with, so you will see serious pro photographers, who you think would always vote for the "never throw away" logic of RAW, tell you they work mostly in JPEG. I'm one of them. I use raw only for shots with high dynamic range, like night photography, and often shoot RAW+JPEG to work with the JPEGs and pull the RAWs if you need it.

Ok, this is something I have to believe somebody else has thought of, but I haven't seen it, so I thought I would ask readers if they have, and if not, to put it forward.

Everybody has a socket wrench set. The wrench heads tend to come with a square hole in the top, typically 1/2" or 3/8" square, into which the square drive from the ratchet inserts. There are sometimes spring-locks to keep it in place.

I've just returned from Denver and the World Science Fiction Convention (worldcon) where I spoke on issues such as privacy, DRM and creating new intelligent beings. However, I also attended a session on "hard" science fiction, and have some thoughts to relate from it.

Defining the sub-genres of SF, or any form of literature, is a constant topic for debate. No matter where you draw the lines, authors will work to bend them as well. Many people just give up and say "Science Fiction is what I point at when I say Science Fiction."