Nicole

Check it out... 0:06

Barry Chan

I end up watching the whole 10 mins, didn't realize the roundabout is better than 4 way stop!
Oh the white 928?

Vilhuer

Its leftover from their 928 is more aerodynamic backwards experiment.

mickster

It doesn't matter what we use in the U.S., we still suck at following the rules.

Nice model!

brealytrent

+1
Yep, saw that episode. Won't spoil it for the rest of y'all.

Alan

My observations of american 4 way stops says they work much worse than was depicted - with pauses and frequent abuses causing extra delays. Meanwhile roundabouts do work more or less as depicted. I think the real difference is much larger than 20%. However roundabouts do take up more room for a similar # of lanes. However a single lane roundabout might be close to the efficiency of a dual lane 4 way stop (Since 4 way stops don't efficiently scale with lanes - far too many morons). Roundabouts actually scale reasonably with more lanes (for those who know how to use them).

If you spent any time in Europe - you wouln't have any doubt about the efficiency - its blindingly obvious that its much much better.

However American drivers don't adapt well to it. We have few in Arizona - some are placed in retail parking areas - there people routinely drive around them the wrong way (beacause its quicker that way.... !!WTF!!)...

Note that here they were looking at the max capacity efficiency - its also more efficient from a minimum time efficiency and fuel efficiency. If there is no traffic you don't have to stop at all. When you get good at roundabouts you look ahead and slow appropriately to time your entry so you can maintain the smoothest entry with the minimum of total slowdown (conservation of momentum). This is a smoother drive, quicker and the least energy wasted in braking and starting again from a stop.

Alan

WallyP

We have several local roundabouts (suburban area North of Atlanta, pretty heavy traffic everywhere. Generally work well on most applications - but there is a problem...

Visualize a crossroad intersection of a N-S road and an E-W road. At certain times of the day, commuter traffic is extremely heavy heading South on the N-S road, with moderate traffic on the E-W road.

Under these conditions, you will never get into the roundabout from the West. The constant stream of cars from the North will block entrance from the West continuously.

bronto

We have a bunch in Santa Barbara, and are getting more. Roundabouts have significantly reduced congestion at particular intersections, to the point where there just isn't any congestion anymore. There are positive side effects too. One intersection near my house used to be "homeless handout central", where they would stand at a stop sign in the median and ask for change. Guaranteed attention since every single car had to stop next to them. There hasn't been anyone there since the roundabout went live 2 years ago because there's never anyone stopped there.

The only downside is the many tourists who come through and have no idea how they work. "It's not a fricking stop sign! Go!!!".

Vilhuer

They could have made round about work even better if they had followed correct regulations. When exiting from roundabout driver must turn right side turn signal on when car has just passed previous exit. This lets others know car will turn off at next one and they can enter roundabout quicker. Its usually possible to see where car is going to exit based by its movement but adding turn indicator into mix makes it easier. This should get few extra cars through intersection over 15 minute test period. Replacing stop signs on normal intersection with traffic lights would make difference even bigger.

mickster

In theory.

Come to New York-to Jones Beach-where there are clear YIELD signs before entering the roundabout...I had a Ford Expedition SUV almost take out my Honda because he decided to enter, didn't stop and was going to continue around-even though I was in the outer lane (3 lane) with my right signal on. Right of way is not understood here.

Same thing out in the Hamptons. I've seen too many near misses.

eijun

Well once they get used to it then it is good but if it is just introduced then people hate it like a passion which requires at least a year for some people learn how to drive it. (it is not even in our DMV book either from the last time I looked in it)

In San Diego we use half roundabouts (just to make it wavy) to slow down traffic being Southern Cali people about 99% of them don't know how to drive around things

Personally I love them especially the half roundabouts being you can kinda have a little fun doing the wave (and yes I drive through it pretty fast)

17prospective buyer

I hate 4 way stops when you're following the rules, then some dumb broad waves keeps waving people through, if you're not confident and assertive driving, don't drive. Roundabouts are great if people know how to use them. Nothing worse than seeing people stop at empty roundabouts, it's a yield and merge you idiots. Conversely, yield doesn't mean "do what you want, every man for themself".

While we're talking about driving, i also hate people who charge up to red lights and get angry at people who save their brakes. Like, how about, hey it's red, you're going to have to stop anyways, so why not just take your foot off the gas pedal and also save some wear and tear on your vehicle, nope... not in Canada/USA. Idiots driving domestics seem to be the worst for this, especially moms in Grand Caravan's... worst offenders for driving the **** out of their vehicles. Hell, with a manual sometimes i see how long i can go without my brake lights coming on, drive it like a semi.

RKD in OKC

Actually had a policeman stop and asked if my brakes worked because I coasted to a stop light behind him and it turned green just as I pulled up.

OTR18WHEELER

I have two problems with this experiment!
1) round-a -bouts arent designed for big trucks
2) prius drivers are idiots

Ketchmi

We have a few round-a-bouts here in Utah and all they do is confuse the locals. You would be suprised just how many people actually go around one complete revolution before figuring out where they want to go.