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.”
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 to a 90 percent,points than four-way intersections (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
South Florida chiming in to say they’re great, if and only if people understand them. And understanding requires building them big enough that people don’t go “weird bump in the middle of this two-way stop.”
Admittedly a huge aspect of that problem is Florida drivers. Our road-going population is an even blend of people so old they could be in congress, overly-cautious Canadians with no sense of direction, pristine 1980s Toyotas that obey every law because they don’t have insurance, and (varying by coast) New Yorkers who view driving as ritual combat or midwesterners who’ll wave six cars through a four-way stop.
Personally I’m a huge fan of the German model, which is often an enormous ring with perpendicular junctions attached. It immediately conveys how incoming traffic is intruding on traffic in the circle. Ze Germans are very serious about right-of-way. Honestly I don’t even trust people down here to understand you have to stop at the stop sign, not just, in the lane, at some point, behind a guy who did. Similar issue to California drivers not getting that you have to stop at the stop sign, not just crawl through and hope for the best.
Maybe there’s a reason I’ve been optimistic about self-driving cars.
Ha! Both funny and fairly accurate descriptions. I appreciate the seriousness of some of the European drivers, but it’s apparently crazy expensive to get a license and plates there, so they don’t play.
I am very excited for self driving cars, just need them to get better. They still some of the same dumb things we do,.just maybe statistically less on a grand scale?
Better statistics would suffice. We let people drive, and people suck at it.