Carmel, Indiana has been replacing signaled intersections since the late 1990s, earning the city international recognition for its use of what many argue is a much safer road design. While roundabouts have both advantages and disadvantages, they are so popular in Carmel that the city now has over 142 roundabouts — more than any other American city.
As state and local governments across the US decide whether roundabouts or intersections are best, it should be remembered that no traffic design will ever be accident-proof. But does the evidence support Carmel’s embrace of roundabouts? Our experienced car accident attorneys at Sevenish Law Firm take a look.
What Are Roundabouts?
Also known as traffic circles, roundabouts are alternatives to signaled intersections. The simplest roundabouts are circular one-lane intersections or junctions in which traffic is allowed to flow in only one direction around a central island. Cars enter the roundabout when traffic allows but priority is given to the vehicles already in the traffic circle. There are more complicated designs such as multilane and double teardrop roundabouts.
This traffic design is so widespread in Carmel that the city has become known as the Roundabout Capital of the United States. Carmel even offers an informational brochure on the city’s website that instructs drivers on how to use roundabouts. Although this raises an interesting objection to the roundabout – namely that many drivers are unfamiliar with them – Carmel claims that they make traffic safer and offer a number of other advantages.
What Does the Data Say?
Are roundabouts safer than intersections? It is widely accepted that Carmel’s use of traffic circles has reduced automobile accidents, including serious wrecks with injuries. Even though Carmel’s population has quadrupled since the 1990s, when the city began implementing these traffic designs, accidents with injury have decreased by 78% in places where roundabouts have replaced traditional intersections.
In 2021, only one fatal accident happened at a roundabout in Carmel while all the rest occurred at intersections with a stop sign on a two-lane road or a divided highway.
A recent study from the Insurance Institute for Highway Safety found that the double-teardrop design that Carmel installed at several busy intersections reduced injury-causing crashes by 84 percent and all crashes by nearly two-thirds.
Meanwhile, single-lane roundabouts caused a decrease in total crashes and property-damage-only crashes by 51 percent and 50 percent, respectively. Finally, while multilane roundabouts were associated with increases in the total number of accidents and property-damage wrecks, injury crashes dropped by 15 percent.
What Are the Benefits and Drawbacks of Roundabouts?
Carmel’s enthusiastic adoption of the roundabout has demonstrated that there are both pros and cons to this traffic design.
The advantages of roundabouts include:
In addition to reducing the number of accidents, traffic circles slow drivers down and allow them more time to make careful driving decisions. The curved design of roundabouts eliminates head-on and high-speed right-angle collisions. There are also fewer conflict points (places where two vehicles may collide) versus traditional intersections.
Roundabouts allow pedestrian and bicyclist crossings, and the improved traffic flow makes it safer to walk and ride a bike in these areas. Traffic circles are also usually more aesthetic. The center of the roundabout can be landscaped with grass, flowers, and other visually appealing designs.
Less gas, fewer emissions
At a time when there is more sensitivity to a healthier climate, roundabouts fit in well. Carmel’s traffic circles have saved drivers about $14 million in annual gas costs, removing the equivalent of approximately 5,000 cars’ worth of carbon emissions. Less idling means less gas being burned and better fuel economy.
Without signaled intersections there are no stoplights to install and maintain. Roundabouts cost about $125,000 less than signaled intersections to construct. Plus, fewer wrecks save money for motorists and result in less pressure being placed on limited police and emergency resources that would otherwise have to respond to more accidents.
In contrast, disadvantages of roundabouts include:
Even among Carmel residents, some motorists may not fully understand how to properly use roundabouts. That’s understandable since most drivers are more familiar with signaled intersections. Although traffic signs are used to advise drivers and others of traffic circles, it can take time for people to get used to them.
As mentioned above, multilane roundabouts can actually increase accidents. The presence of more than one lane allows drivers who lack lane discipline to collide with others. Also, drivers often signal right at traffic circles when they intend to go straight, confusing other motorists and increasing the risk of a wreck. Finally, although roundabouts slow drivers, many approach them at too high a speed, thereby endangering others.
While roundabouts cut many of the costs associated with signaled intersections, the inner circles – which are typically landscaped – must be maintained. Crews have to access the inner circle to mow or do other work, which can also disrupt traffic.
Narrower shoulder lanes for bicyclists and pedestrians
Roundabouts need more space than traditional intersections, causing them to lack a broad, defined shoulder. This makes them less safe specifically for bicyclists and pedestrians, and sometimes for drivers.
Roundabouts Will Never Totally Eliminate Accidents — That’s Why We’re Here
The roundabouts vs. intersections debate is ongoing in cities and states across the country. Whether roundabouts are really safer than intersections, they will never totally end automobile wrecks.
If you or a loved one has been injured in an intersection accident anywhere throughout the Indianapolis metro area, reach out to Sevenish Law Firm. Indianapolis auto accident attorney Randall Sevenish and his team are ready to get started on your legal case today. Contact us for your consultation.