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The solution to traffic jams is to have a dynamically calculated speed limit based on the density of the traffic flowing through it. A car going 60mph down the
by freework 13y ago
The solution to traffic jams is to have a dynamically calculated speed limit based on the density of the traffic flowing through it. A car going 60mph down the highway needs 50 feet in front and 50 feet in back between it and the other cars (for braking distance). When that same car is going 20 mph, you only need 10 feet in front and back. Therefore, to support more cars, speed needs to slow down. You could have a device that counts the amount of cars entering the highway, and then an algorithm could assign a speed limit for a section of the highway. In the middle of the nigh, theres no one else on the road, so the speed limit will be very high. During rush hour the speed limit could be as low as 15mph. This would make merging easier since you're going slower.
You wouldn't think that lowering speed limits would easy traffic congestion, but it would. Its a counter-intuitive, so it will never be implemented anywhere.
- pmenage 13y agoIt's already implemented on the M25, the orbital motorway around London. It gets used quite frequently to slow commuter traffic down from a limit of 70mph to as low as 40. There's a particular incentive there because being a loop a bad traffic jam could (theoretically - I'm not sure it's ever happened) stretch so far that its head and tail collide. Plus, of course, the fact that the M25 was demonically planned in the shape of the mystic sigil Odegra, from the alphabet of the Black Priesthood of Ancient Mu.
- lostlogin 13y agoIt's done in central Auckland too.
- ygra 13y agoMany German motorways use that system and have dynamic speed limits based on the current traffic situation. The downside is that most people think »Why the hell should I drive 100 now when I can still drive 120?«, so depending on the mindset of the drivers this may or may not work. I rarely see those speed limits followed or enforced.
- ronaldx 13y agoVariable speed limits are well implemented on UK motorways. One thing I find interesting is that, as a traveller, it's completely impossible to fathom what's going on. Because the signs are on in apparently free-flowing traffic, it's really not clear whether the signs are providing any use or are just still turned on from a earlier occasion.
- foresterh 13y agoThey put up dynamic (digital) speed limit signs in Seattle (where this article is based) in the last year or do, and I've been wondering how effective they are. After reading this article I feel like this is the reason. There is one speed limit over each lane when it's slower than the regular posted limit, which to me seems like if you see your lane slower than the one over from it, you'll merge, causing next lane to go slower. Reading the article, and the comment above,I can now see the purpose of the dynamic signs. But unless drivers adapt a mentality that's best for the traffic and not themselves, this doesn't seem like it would work.
- coryrc 13y agoI've yet to see someone follow them.
- codfrantic 13y agoThis Happens in the Netherlands too, we get cut down from 120/130 to 100, 80, 70 or even 50 kph.