Reputation system for cars and the selfish merge.

George Carlin once proposed a system where people would shoot suction cup darts at cars when they did something annoying, like cutting you off, and if you got too many darts the cops would pull you over. Another friend recently proposed a lot of interest in building some sort of reputation system for cars using computers.

Though Carlin's was a satire, it actually has merits that it would be hard to match in a computerized system. Sure, we could build a system where if somebody was rude on the road, you could snap a quick photo of their licence plate, or say it into a microphone or cell phone for insertion into a reputation database. But people could also just do this to annoy you. There's no efficient way to prove you actually were there for the rude event. The photos could do that but it's too much work to verify them. The darts actually do it, since you could not just stick them on my car when I'm stopped, or I would pull them off before driving.

One problem I want to solve with such a system is the selfish merge. We've all seen it -- lanes are merging, and the cooperating drivers try to merge early. Then the selfish drivers zoom ahead in the vanishing lane until they get to its end. And always, somebody lets them in. Selfishly zooming up does get you through the jam faster, but at the same time these late mergers are a major contributor to the very jam they are bypassing.

We'll never stop people from letting in the drivers, and indeed, from time to time innocent drivers get into the free lane because they are not clear on the situation or missed the merge.


I've wondered if one could create a special portable traffic light for these merges, which is green for the true lane, and much more rarely green for the vanishing lane, and have the lanes physically divided for a stretch before the light, and illegal to stop to let somebody in. I doubt people could learn that rule though, and of course we might just create the jam where the physical barrier (rubber poles) begins instead of where the lanes merge.

A working reputation system could have people tag the cars that do the zoom-by. This would be harder to fake as a typical zoom-by would get you a whole bunch of tags, all from distinct people if there were lots of people joining the system. It need not be a cell call -- any voice recorder could be dumped later to a PC or other location to enter the plates.

But then what do we do with the data? Public humiliation? Only if you can map plates to names. Possibly random police ticketing of repeat offenders for failure to merge? (ie. cops occasionally watch merges, or even direct traffic at them, and if they see a regular selfish merger who didn't merge in time, they get a very fat ticket and -- this is important -- are delayed for a long period.) The law would have to be written that in any lane merger, the last 500 yards of the vanishing lane may only be used if traffic is flowing freely in the continuing lane, or something similar.

But none of these solutions excite me, which is why I put a Solve This tag on this post.


I've also thought about the 'selfish merge' problem a lot. I think the solution is that instead of one lane vanishing and all cars moving into the other lane, both lanes should partially vanish, so you 'merge' into the middle of the two lanes.

I saw this in Brussels once and it really caught me out. I thought the other lane was vanishing so made no attempt to merge with the other traffic, but my lane was also vanishing. It means that drivers in both lanes must be considerate. If I'd expected this format it would have worked very smoothly.

I try to mimic this form of road design in my driving anyway, by intentionally driving halfway between the disappearing lane and the continuing one. I worry that I'm annoying other drivers too much though.

Your viewpoint that the selfish people are the ones 'zooming by in the closing lane' is skewed.
To put it bluntly there are two lanes, use them. The selfish people are the ones in the not closing lane pissed off about the people trying to merge.

Two lanes carry more traffic than 1, therefore traffic should use all the lanes avaiable for as long as possible.
The shorter a 1 lane road is the more traffic it can carry, thus making a 1 lane road longer by merging early make it flow slower.

If people would use both lanes two things would happen;
1. nobody would zoom by, since all the lans are full. ( wouldn't that be nice)
2. The traffic jam would be shorter, but wider.
3. Since no one is zooming by and cutting in disruptions to traffic flow will smoother.
4. Blood pressure will drop.
5. Overall time in traffic will be shorter since merging will happen in one place not randomaly along the length of the traffic jam.

The custom I remember from the State of New Jersey is that both lanes are used by drivers as far as possible, and then when merging is inevitable the lanes take turns, one by one. In Tennessee, there seems to be an opposite rule--everyone moves to the merged lane as early as possible, leaving the other lane empty. This works if only people with urgent business charge up the empty lane and merge in. Maybe that's the idea. But the New Jersey method is easier on the nerves.

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