how can we reduce traffic jams on the roads

"Pressure system" ??? ROTFLMAO :-)

...Jim Thompson

Jim, Jim, you've obviously got *way* too much business. You need to get out more. Even in Phoenix there must be funnier things than that going on within a block or so. ;)

Cheers,

Phil Hobbs

Virtually EVERY traffic control here in Phoenix is via buried-loop sensors, but some new installations are using imaging/motion sensors.

I don't think I've ever seen "pressure" sensors used for traffic lights... at least not for around 40 years.

...Jim Thompson

Hello Jim,

He said "pressure system". Very common in southern Europe and other countries. Drivers in front are pressured into moving it by a concerto of horns, cussing and the occasional tap of bumpers. Can, on occasion, also be experienced in NY. On the Van Wyck Expressway, for example.

Regards, Joerg

ROTFLMAO! Do that around here and you will be shot at ;-)

...Jim Thompson

able

Don't laugh too hard, there are some still scattered around Houston. I don't know if any are still active, but the rubber covered sensors are still in place. Of course, you couldn't prove by me that any of the loop sensors work either. Houston has to be the worst city in the US for congestion caused by so-called "smart" traffic lights that seem to be completely brain-dead. Come to houston and stop at >90% of the lights that you encounter. It sucks big time.

Or, you can live in a city like Irvine, with very expensive 'smart' controllers on the traffic lights. They will optimize them for 'one direction' of travel, which basically means that the other direction WILL STOP AT EVERY POSSIBLE LIGHT!

Also, I have found out that they sometimes INTENTIONALLY schedule two lights to stop all the drivers. Seems, they didn't want it to be TOO convenient to zip through town. They wanted folks to go around if they weren't intent on shopping there...

Charlie

Or like Phoenix... turn off the left-turn-arrow functions during rush hour.

"Traffic engineer" is an oxymoron.

...Jim Thompson

That can be a valid traffic control solution, *if there's an alternative*. And that's the key. In Melbourne (Australia, not the cheap imitation in Florida) they re-hashed the intersection construction and the light sequences to make going around the CBD easier, and unclogged the city in the process. Years later it's all screwed again, but that's progress for ya!

Here in New Zealand we have dysfunctional traffic, an 'intelligent' light control system which doesn't work and no public transport to speak of. One argument I hear pretty often is that trains aren't required to be put in because no-one uses them here.

Cheers.

Ken

Three rights makes a left.

That's what the clown in traffic school kept harping about. I think he's just afraid to turn left ;-)

...Jim Thompson

How about using 'roundabouts' - think they are called 'circles' in the US. Seem pretty efficient in UK at keeping traffic flowing

- most places no power, no software, few failure modes ...

"neil" wrote in news:DVwEf.14087$ snipped-for-privacy@text.news.blueyonder.co.uk:

No power, no software, no one bothering to look before entering, starvation (ie if traffic from across the intersection is streaming through to the direction past you (270 degrees) you may not have a chance to go for a long time.)

Traffic problems are going to exist, no matter what you do. However, there's no reason that I should stop at all 9 traffic lights between the interstate and my destination at an off-peak time.

Puckdropper

Doesn't it mean that it takes three right-wingers to be equal to one left-winger? ;-P

Cheers! Rich

Ken Taylor wrote: ...

In fact, only one technique has ever solved traffic problems, or even made them manageable, for any length of time.

Of course, you have to have a reasonable mass transport system in place first. But nothing else has ever worked.

BTW, I'm not an adherent to city life -- I despise cities. The bigger they are, the worse I hate them. But they're a necessary evil, given our population levels.

John Perry

They already have 'smart' traffic lights with sensors, controllers, variable timing, etc. But it seems to me that the traffic engineers don't really have a good handle on how to coordinate signals over a large area.

Interesting observation: One of the worst stretches of road, in terms of signal coordination, that I travel on frequently enough to observe, is the one that runs right through the main Microsoft campuses. Perhaps they have developed systems that can propagate software bugs by mere proximity ;-). Some of the light changes are so poorly timed that pedestrians have to make a run for it. Its actually pretty funny to watch some of them trying to cross between the campuses, since many Microsofties (known for their diet of pizza and Jolt cola) don't move too fast.

Another interesting observation: One other signal timing 'disaster' is at an intersection leading into a small residential neighborhood just off a local freeway exchange. It seems that the traffic engineers have set the signal logic to give the neighborhood residents a green light without any delay when they approach the intersection. In fact, the intersection has been fitted with a second sensor loop about 100 yards back, so that an approaching vehicle from the side street doesn't even have to slow down to switch the signal. During rush hour this has the effect of backing traffic up on the freeway off ramp and onto the freeway. From time to time, the signal timing seems to get 'fixed' to improve the off ramp flow. But without fail, within a few weeks, the signal priority gets switched back to favor the side street. The moral of the story is that traffic flow is often more dependent on political favoritism or bribes than common sense.

Roundabouts rarely have that problem. Streaming straight across is never continuous and every time a vehicle turns right or left off the main stream it 'pauses' the roundabout, and allows you to jump into the gap.... jump being the usual operative word these days though.

The reality is roundabouts give more flow than triffid lights, much less driver delays, and share flow effectively between all entrances. This is why Britain, with one of the most cars per mile of road in the world, has converted extentsively to roundabouts.

NT

Not always. Sometimes one of the right turns isn't possible, or it will take you a lot of miles out of your way. Then you can add road construction, one way streets, and dead end roads.