Let's Play Date, Marry, Kill...with Roundabouts.
What are your thoughts as Indiana starts adopting these modern traffic control measures (Europe has been doing them since...forever)?
Most people I talk to either love or hate these intersections. For some reason, I can't find people who are indifferent to them very often.
According to the Carmel's city webpage: "Carmel is internationally known for its roundabout network. Since the late 1990’s Carmel has been building and replacing signalized intersections with roundabouts. Carmel now has more than 150 roundabouts, more than any other city in the United States."
"The number of injury accidents in Carmel have reduced by about 80 percent and the number of accidents overall by about 40 percent."
https://www.carmel.in.gov/government/departments-services/engineering/roundabouts#:~:text=Carmel%20is%20internationally%20known%20for,city%20in%20the%20United%20States.
General PROs / CONs
- Up to a 90 percent reduction in fatalities
- 76 percent reduction in injury crashes
- 30-40 percent reduction in pedestrian crashes
- Reduces the severity of crashes
- Keeps pedestrians safer
- Roundabouts reduce the number of potential accident points within an intersection, 75 percent fewer conflict points than four-way intersections
- No signal equipment to install and repair, savings estimated at an average of $5,000 per year in electricity and maintenance costs
- Service life of a roundabout is 25 years (vs. the 10-year service life of signal equipment)
- Reduces pollution and fuel use
- 30-50 percent increase in traffic capacity, improves traffic flow for intersections that handle a high number of left turns, reduces need for turn lanes
- While roundabouts can handle moderate to heavy traffic volumes more efficiently than traditional intersections, they may experience congestion and delays during periods of extremely high traffic volumes or if not designed properly for the anticipated traffic flow
- Pedestrians and cyclists may face challenges navigating roundabouts, particularly multi-lane roundabouts with higher traffic volumes. Proper design considerations, such as providing safe crossing points, adequate sight lines, and dedicated pedestrian/cyclist facilities, are crucial to ensure their safety.
- Drivers unfamiliar with roundabouts may initially experience confusion or hesitation when navigating them, potentially leading to increased risks or delays until they become accustomed to the traffic patterns.
- Roundabouts generally require a larger footprint and more land area
https://www.in.gov/indot/traffic-engineering/roundabouts/#:~:text=Up%20to%20a%2090%20percent,points%20than%20four%2Dway%20intersections (CONs came from general searching, LLM compilation)
Indianapolis and the surrounding suburbs are implementing them more frequently now, how about your city?
Did you know that traffic circles are different from roundabouts? PA has a little comparison chart that was interesting (If you're into that sort of thing): https://www.penndot.pa.gov/PennDOTWay/pages/Article.aspx?post=24
I live right next to an intersection that was a 4 way stop that was changed to a roundabout. I hear way more honking now than I did when it was a 4 way stop. People just don't understand yielding.
Personally, I went from hating this idea, to loving it after I starting driving in them.
After spending time driving in Carmel, I can't stand traffic lights anymore. Everything got downgraded in my mind: Traffic lights became stop signs, stop signs became yield, yield became...well still yield (I'm not a sociopath).
Sound places have built terrible versions of roundabouts, so I'm sure those populations aren't impressed.
I did drive through one that was off an interstate exit and had heavy tractor-trailer traffic, that actually directly connected to a truck stop. To my surprise, it was glorious. It was fairly large, so the trucks had plenty of ability to go around without running over curbs, and it made all the traffic going in and out of the big truck stop / gas station pretty smooth. I was genuinely impressed. I think it was southern Indiana around the 69 project, but I can't remember.
Something I've noticed but I haven't been able to find any data on is that roundabouts seem to be bad for pedestrians in a high foot traffic area.
Even if drivers know how to navigate a roundabout in America (and that's a big if), adding pedestrian crossing to the mix seems to confuse drivers even more. And for the pedestrian, the near constant flow of traffic is intimidating.
Again, in have no data here. But if I'm crossing a road on foot or with a bicycle, I'd rather have a stop light.
In Europe roundabout means no stopping for traffic lights for bicycles and pedestrians which is a huge plus. Idk what you understand under high foot traffic but the only scenario I can think of where there would be too much foot traffic would be in city centers which shouldn’t be open for cars anyways
So where you are from, what happens if a pedestrian or bicycle needs to go across a road? Is there infrastructure like bridges to cross the road without cars needing to yield?
Cars yield for cyclists and pedestrians. This only works for smaller intersections like in the picture. Large roundabouts have traffic lights, but those are in the outskirts of a city where traffic consists of cars for the most part
Interestingly, but not surprising, there's a shopping mall called Clay Terrace in Carmel that is basically walkable strip mall.
It has a lot of cross walks and two circles. I find there's people who yield readily because they know the area is intended for pedestrians, and some treat it like regular roads. They put up flashing crossing lights when people pass sensors. That helped a lot.
Don't hate the idea but the few that I've been on around my parts seemed like they were an after thought.
Turning an old 4-way intersection into a tiny roudabout with a giant "feature" in the middle that makes it hard to see traffic coming across the way. Sometimes the circle so tight I feel like a racecar driver going 60 instead of a commuter motorist going 20, either way its about 50/50 whether I feel like I'm cutting off vehicles on my right as I'm trying to turn onto the street just past where somebody else pulled into the roundabout. A few other times, when driving someplace I don't normally drive, the roundabouts are very large and spacious but blend in so well I don't realize I'm coming up on one.
Ha, youi right about people going too fast in then. I see a soccer mom van going under the speed limit until they get into a roundabout, then it's Tokyo drift time. I'm usually unlucky and following them out just to return to painfully under the speed limit again. I'm the opposite. Faster on straight where no pedestrian and slow in circles. Slower in circles means people can merge in better and with more confidence like you mentioned.
I think the land scraping serves two purposes, stop a run through, and it visually blocks traffic since you've only supposed to be concerned about traffic to the immediate left I think.
I think the land scraping serves two purposes, stop a run through, and it visually blocks traffic since you've only supposed to be concerned about traffic to the immediate left I think.
Which makes sense but between the tight circles and potential for speeding its a bit nerve wracking. I've looked to my left and seen that road clear, go to pull out into the roudabout only to need to slam on my brakes because somebody that I cant see entering from the opposite road was doing, as you said, some Tokyo drifting.
Now it doesn't happen all the time and I'm not saying that roundabouts are a menace or anything. Just trying to get used to them in places where they weren't originally planned for and a whole ass adult lifetime of driving without their existence makes me feel a lot like
