4-way stops vs. roundabouts: which is more efficient? Mythbusters tests both (vid)

[euromodder]

Well, we do use over/underpasses here, when & where there's enough space available.
So they're not abundant, but we got some.

The Brits often use 2 bridges on Motorway entrance/exit complexes, with a big roundabout laid out over the Motorway.
That's also quite costly, but it has the added advantage of physically preventing people from going the wrong way on the motorway - whereas in Belgium the exit and entrance are often right next to each other, and relatively many people take the wrong one ...

[euromodder]

Originally Posted by MetroMPG

A funny thing: my brother is the municipal civil engineer where I live. He's the guy who decides on things like traffic lights vs. traffic circles. He hasn't put in one in 25 years.

Is that 1000 Islands in the St Lawrence ?
Not exactly your typical municipality

Part of the problem is we have an unusually high concentration of seniors who don't like/adapt well to change (my take, not his).

We have over 20% seniors.
They adapt better than some youngsters.

[cptsideways]

The latest annoyance in the UK is traffic lights on roundabouts, they are adding them everywhere! Whoever thought they are a good idea should be shot.

[redpoint5]

I just got back from a trip from Bend, Oregon, and they use roundabouts extensively. Since I don't often see roundabouts, it got me wondering how efficient they are. Good timing on posting this topic.

Under light traffic conditions, there is a good chance a vehicle won't even have to stop which will preserve the momentum. I wonder if that had anything to do with me getting the second best MPG to date; 35mpg in my 205hp TSX. Of course, the constant elevation gain and loss was the biggest contributor to this excellent tank.

[MetroMPG]

Originally Posted by redpoint5

Under light traffic conditions, there is a good chance a vehicle won't even have to stop which will preserve the momentum.

Under ideal conditions, you get to flick the car right & left (or left & right, depending on locale) and have a lot of fun, too!

---

Euromodder: yes, on the St. Lawrence River. Not too many boat traffic issues, except on sailboat racing nights.

[flying kurmaster]

I have lived in NZ now for16years and love roundabouts, not only are they efficient even in heavy traffic areas, once everyone knows how to use them but they also save on electricity and maintenance. I grew up in North America without them, other then a few silly ones they added to slow traffic in congested neighbourhoods( Vancouver West end)which were just plain silly. In the Ottawa valley I noticed that they are starting to install them and when they first did this a few years back I could not believe the complaining on the talk shows and the crazy way people thought they worked. The way they first used them was very inefficient, a bit like a four way stop but only different. However last summer, three years on, I noticed that people are getting the hang of them and they have become very efficient as they should be. I aslo noticed that they are starting to embrace them. As mentioned by someone, my elderly Mother avoids them if she can. The other thing that should be standardized is how everyone signals on entering and exiting, What makes sense to me is if your intention is to turn right you singnal right just before entering, left the same, if you intend on going straight through no signal that way everyone waiting to get in knows what is going on. If there are more then four exits or you are doing a u turn you just live your signal on in the direction you are going until just before your exit then signal your exit. that way the guy waiting at the next exit can go and not sit there guessing.

[redpoint5]

Originally Posted by MetroMPG

Under ideal conditions, you get to flick the car right & left (or left & right, depending on locale) and have a lot of fun, too!

This reminds me of the first time I encountered a roundabout when I was 17. It was late at night and I had a few friends in the car and decided to show off by going round and round as fast as the old Volvo would go. After about the 3rd go-round, I noticed a parked police car and an officer looking very intently at me. Rather than make him chase me down with the lights on, I just drove up next to him and rolled down my window to hear his lecture. "That reckless driving is a $$$ (I don't remember the amount) citation."

"Wow", I said. Then I drove off.

I might not speed round and round anymore, but it doesn't stop me from enjoying the flick right and left at speed

A typical Bend, Oregon roundabout


How Uhmericans do roundabouts

[eco_generator]

Originally Posted by darcane

I love roundabouts, and we are starting to see them show up in Washington. Near my old house, there was one traffic light that I had to wait at for about 20 minutes a day as rush hour traffic slowly filtered through it (1+ mile backup every day). Once it was replaced with a roundabout, there was NEVER any delay.

^ This ^

On my way to a job I had for a decade there was a light-signaled 6-way intersection. One leg out of 6 was coming from a large mall area 4 miles down the road. Constant turn-off-your-car-and-catch-a-quick-nap waits day and night (or accelerate to 70 to try and catch that infernal green light). Rush hour had mulit-light cycle backups on 4 legs. It was replaced with a relatively small round-a-bout and there is no back up with traffic... ever. The major leg from the mall area has 2 lanes entering the circle and everyone else has no problem getting in natural gaps or where those cars are coming off.

And the larger the circle... the more efficient the round-a-bout. The mythbusters circle was unrealistically small. No way you're getting a fire truck through that in real life, unless that center circle is just a rolled curb onto brick or more pavement. A larger circle can hold more cars and maintains higher speeds.

The ultimate round-a-bout is an interstate ring road around a major city. 50+ mph and no waiting.

[HAHA]

Be careful what you wish for...


Search for "magic roundabout" to study the concept...

[jeff88]

I think I may have heard of this one before. Is this the one that has round-abouts inside of round-abouts?

Duhmericans would be crashing every hour in that thing!