Carmel, Indiana, a city with just over 100,000 residents, has taken an unconventional yet forward-thinking approach to urban planning and traffic management. This small city boasts more than 138 roundabouts, making it the city with the most roundabouts in the United States—a title it proudly claims on its website. This distinctive feature not only sets Carmel apart but has also been a key factor in its push towards increased community resilience, safety, and sustainability.
The journey of Carmel’s roundabout revolution began in 1996 when city leadership looked for solutions to improve pedestrian conditions and traffic flows. The inspiration came from Europe, where roundabouts are a common sight. Carmel’s Mayor, impressed by the walkable communities he experienced in Europe, embarked on a mission to transform the city’s transportation infrastructure. Since then, more than 120 intersections have been converted into roundabouts, funded by a blend of local, state, and federal sources and executed by multiple government departments.
The impact of this transition has been profound. Not only have roundabouts saved Carmel money in terms of construction and maintenance costs, but they’ve also improved air quality by reducing vehicular emissions, enhanced traffic safety, and augmented community walkability. Moreover, the inherent efficiency of roundabouts in facilitating traffic flow has eliminated the need for electric stoplights, an advantage that becomes crucial during power outages, which are anticipated to become more frequent with changing climate conditions.
Roundabouts have been shown to result in approximately 80% fewer crashes that cause injury or death compared to traditional intersections with stoplights or two-way stops. This significant improvement in traffic safety is attributed to the “yield-at-entry” rule of modern roundabouts, where drivers must yield to traffic already in the circle. This feature reduces the incentive to speed up to beat traffic signals, leading to more controlled and safer traffic flow.
Carmel’s efforts extend beyond just installing roundabouts. The city ensures that its streets accommodate various forms of mobility, including cycling. Roundabout construction has facilitated the creation of multi-use paths, providing a safer and more appealing experience for cyclists. This inclusivity aligns with Carmel’s vision of a denser urban core with increased public transit use.
The financial savings from the switch to roundabouts are impressive. In comparison to signalized intersections, the city has determined that roundabouts cost $250,000 less to build and save over $5,000 per intersection annually in electricity costs. Furthermore, since roundabouts help keep traffic moving efficiently, there is less need to add extra lanes—a considerable expense Carmel has avoided.
Not only has Carmel seen a reduction in the number of traffic accidents, but it has also realized significant fuel savings. The city estimates that each roundabout saves about 24,000 gallons of gas annually, which, with more than 120 roundabouts and an average gas price of $2.50 per gallon, equates to over $7,200,000 in savings each year. Additionally, these roundabouts contribute to large reductions in local air quality emissions, including nitrogen dioxide—a pollutant linked to respiratory issues.
While some argue that roundabouts may not be the ideal solution for handling heavy traffic or ensuring cyclist safety, Carmel’s experience indicates otherwise. The city has emerged as a leader and a proof-of-concept for the state of Indiana, which has started to incorporate roundabouts in other areas through the state highway department.
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– TIL that the city with the most roundabouts in the world in terms of percentage of intersections is Carmel, Indiana.