Construction that not only interferes with, but alters, our daily lives can become contentious. Humans are creatures of habit, and any form of change requires adjusting. As a Minnesota native, I’m all too familiar with the idea of summer construction that affects those short three months out of the year. It’s not only construction that is questioned, but the changes that are implemented. One of those is road architecture.
Roundabouts can startle drivers at first, but with time, and with the right planning, they are generally beneficial for most drivers. Why are roundabouts implemented in the first place?
The popularity of roundabouts across the United States increased in the 1990s, mirroring the growth of transforming road intersections in Western European countries. The implementation of roundabouts was grounded in safety and efficiency; however, their support is not unanimous.
Rotaries (older traffic circles) were invented in the beginning of the 20th century with the construction of Columbus Circle in New York. This inspired an outbreak abroad when the United Kingdom had developed the modern roundabout in 1956 that we see today. Other countries like France, Norway, and the Netherlands eventually caught on to safer intersections in the 1980s. By 1987, more than 500 roundabouts had been built in the western regions of France, and the expected growth rate was 1,000 per year.
A leading factor supporting roundabouts over stoplights or other signalized intersections is the safety of the design. One of the most common accidents seen at intersections are left turn collisions, which are eliminated with roundabouts. Roundabouts encourage drivers to slow down, decreasing the severity of accidents and offering a safer approach for pedestrians by reducing the crossing distances. Studies in Europe determined that pedestrian accidents had reduced by 75 percent. This effect has been led by multi-lane roundabouts, which are said to encourage drivers to yield to pedestrians 2-3 times more than with single lane traffic circles.
Statistics measured to support the safety of roundabouts include a reduction in injury crashes of 72-80 percent and reduction in all crashes of 35-47 percent. A 2004 study estimated that if 10 percent of the signalized intersections in the United States would have instead implemented roundabouts, approximately 51,000 crashes could have been prevented. An earlier study, done in 1992, explained why the French were so eager to normalize the circular intersection, as they had determined that within roundabouts there were only four accidents per 100 million vehicles. This average was three times less than the rate of overall reported injury accidents.
With the greater consistency of traffic flow from roundabouts, there are fewer vehicle stops which aids in minimizing emissions and fuel consumption. A study from 2018 reported that if 10 percent of the intersections in the United States would have converted to roundabouts there would have been a clear reduction in fuel consumption by 654 million gallons. Furthermore, vehicle delays would have been reduced by nearly one billion hours. Less traffic benefits both commuters and the environment.
As of 2020, European countries outnumber the United States in roundabouts per one million people, with the U.S. having a mere 73 per million people. By contrast, the top nine countries for roundabouts per million people are: France (967), Spain (591), UK and Ireland (489), Portugal (461), Belgium (423), Italy (396), Switzerland (341), Netherlands (321), and Germany (168). With this data, it is wise to consider the varied country sizes and concentration of roundabouts compared to how it appears in the United States. So, what are the challenges faced by urban planners or city council members for implementing roundabouts?
One setback to roundabout implementation is space constraints. In busy areas, the intersection must be a large enough area to accommodate the traffic volume, but this is also considering that the space topography is fitting, and the appropriate land use is suitable as well. Alongside traffic volumes, the intersection must maintain a balanced traffic flow between corresponding streets, otherwise traffic will be approaching at different speeds on top of different quantities. The planning involved can being intimidating, but without conversions there could be more costs in the long run.
In smaller communities, the implementation of roundabouts is more prevalent in city council agendas. One story in Oroville, California, in 2007, citizens were concerned by the construction of a roundabout on a main road. This was politicized by council members who wanted to support business owners from the area who were worried about accessibility and driver confusion. The road had four to five stoplight intersections already, but Oroville residents had argued that the city shouldn’t fix what hadn’t been broken and that instead of pretty roundabouts, they “would like better roads”.
The roundabout was debated in council meetings and eventually constructed in 2008. In addition, the city recently disclosed that $32 million will be invested into roads and intersections across the city, adding a second roundabout on Montgomery Street- the same road that started the debate. This example reveals the contentiousness of changing intersections, especially for community members who experience these changes and question if new intersections will be more efficient, or will it cause confusion for drivers. In some cases, roundabouts do fail to improve traffic flow and can be removed.
Multiple studies have demonstrated from a community member perspective that the benefits of roundabouts take time to come to fruition. From these studies, 31-36 percent of people on average supported a roundabout conversion before construction and 63-70 percent supported after. Although a federally mandated roundabout policy when constructing or updating intersections would not be widely accepted, many states including New York and Virgina have adopted a “roundabout first” policy when considering driver safety and efficiency. The question is whether roundabouts can regain the momentum from its peak in the 1990s, to improve overall driver safety in the United States.
Written by Tabetha Bowes, Public Policy Intern
The Alliance for Innovation and Infrastructure (Aii) is an independent, national research and educational organization. An innovative think tank, Aii explores the intersection of economics, law, and public policy in the areas of climate, damage prevention, energy, infrastructure, innovation, technology, and transportation.