Roundabouts

[Jon P. Inghram]

I'd love to know if the people who do the research that shows that roundabouts improve traffic flow (and therefor convince mindless city planners to use them) ever bothered to simulate real life where 99% of drivers have less of an understanding about how to negotiate a roundabound than your average diatom? It seems like many people just sit at an entrance to the roundabout and wait until there's nobody in the entire circle before pulling out. And then invariably they stop in the circle to let someone else in! And turn signals? HAHAHA!

[cjolley]

Ha.
When I lived in Germany in the late 60's this was an interesting question.
The Germans did the correct thing and gave the traffic in the circle the right of way.
Most other countries followed Frances (insane) lead and gave it to the traffic entering the circle

How it's handled now I don't know.
We have one traffic circle in OKC and it is done the right way.
I havent noticed any problems there, but it is not a high traffic area.
In the US it would be important for the right of way to be VERY clearly marked.

[Jon P. Inghram]

The two I know of in Wichita have yield signs on the entrances, not that many people understand such strange foreign words. I do like the roundabouts on the rare occasions that people use them properly or when there's no traffic at all.

[ZokesPro]

They installed two of them around my area and they cause more problems than they solve. People here get scared and stop until there's no traffic at all, Sheesh!

And to make things worse the city won an award cause of those stupid roundabouts. (in french they are called "carrefour giratoire" which sounds ridiculous)

[Tjalfe]

I don't recall them ever being mentioned in drivers ed here.. i.e. nobody here knows the proper usage of them. Maybe the government should put an add on tv telling peple how they work.

[JTD]

We have them in Denmark and we learn how to navigate them when we take driving lessons.
This includes the fact that traffic in the roundabout has right of way and proper use of turn signals (both when entering and exiting the roundabout).

[Mikko]

In the town I live, we have SEVEN roundabouts in an area of just 4-6 square kilometers! And this is very small town, only ~15000 people living in very large area. The town center itself is only about two square kilometers.

But I really like these roundabouts. IMO, it makes the traffic more safe. There are some negative aspects, though. When the car is exiting the roundabout and it stops immediately after the exit (because of pedestrian crossing the road), it usually means that all cars in the roundabout at that moment must also stop. And then there are these tourists, who have never driven in the roundabout before...

[Dr Mordrid]

Most Michigan cities avoid them and are laid out on a grid. Detroit has one full one, Grand Circle, and a larger half-circle, Grand Circus Park, both along Woodward Ave. ~ 1/2 km apart downtown, but they have traffic lights;

Google map

[gt40]

We've just had a few put in near us, and suprisingly they did have radio adds explaining how to use them,
but the idiots have made them tooooooo small - there's just not enough room for larger vehicles to negotiate around. (like public transport for example)

[cjolley]

...
but the idiots have made them tooooooo small...

The one here has too small a radius too.
I think that confuses some people because there is soo little distance between connecting streets. Ours is three through streets, which makes for six intersections crammed right up next to each other.

[Technoid]

A year or so ago a goverment grant for roundabouts vere granted, the morons in charge of roads in my city whent batshit crazy and built 5 of them in the city, the grant only covered them in places that were accident prone, none of the places passed muster, gues who got shafted on the bill?
To get from the city to the freway you have to pass 5 roundabouts on a stretch of less than one kilometer

--------------------------------------------
In Sweden those that are in the roundabout has right of way and signals must be used if not crossing straight over (ie entering from north and continuing north after the roundabout).

[Umfriend]

In the Netherlands we do it the only way it should be done. As traffic coming form the right have right of way, a roundabout without signs would have the traffic coming onto the roundabout have right of way. Therefore, all our roundabouts have signs giving the cars on the roundabout right of way.

Roundabouts are bad when the volume going in and out from all sides is badly spread.

@cjolley: it os hte exact same in in France AFAIK.

@Tech: I assume you had 5 crossings with trafficlights before that?

[Dr Mordrid]

In the Netherlands we do it the only way it should be done.

In Michigan this the case for all unmarked or 4-way stop intersections. Broken/power outage traffic lights get treated as a 4-way stop.

[Paddy]

Crazy foreigners!

We have essentially three types of roundabouts.

The mini-roundabout is essentially a traffic calming measure as you can't drive straight over them (although some people still do). The larger roundabouts come in two flavours those with lane markings and those without. Those without lane markings are straightforward. You give way to your right. That way any traffic on the roundabout has right of way. You simply indicate to announce when you are turning off. Those with lane markings tend to cause more confusion and are reserved for higher volumes of traffic. They tend to spiral outwards so that all traffic gradually migrates from the centre to the exit roads. I've seen many an accident where people ignore the lane markings and drive in concentric circles cutting up people on their right.

Simple.

[VJ]

In the Netherlands we do it the only way it should be done. As traffic coming form the right have right of way, a roundabout without signs would have the traffic coming onto the roundabout have right of way. Therefore, all our roundabouts have signs giving the cars on the roundabout right of way.

More or less the same here...
A roundabout implies that traffic on it has right of way (it used to be different!), so there are no signs needed.
There was some commotion with bicycle lanes. Currently, when they are part of the roundabout, cyclists have right of way over any traffic (this can kill the throughtput of a roundabout entirely!). When the bicycle lane is parallel to it, they do not.

I do hate roundabouts with multiple lanes. Traffic on the inner lane has no preference whatsoever (they must change lanes before leaving the roundabout, and thus let traffic on the outer lane go first!). This gives rise to a number of difficult situations.

But there still are moron drivers that either don't use their turn signal when wanting to leave the roundabout, so one isn't like to move in front of them (they appear to be staying on it). Or then the other moron drivers that keep their right turn indicator on the whole time, as if they are leaving the roundabout. One thinks he/she is leaving, accellerates to join the roundabout, and then needs to step on the brakes.


Jörg