Study: Larger Vehicles Lead to More Congestion

New research links large SUVs to increased traffic congestion, reports David Zipper in Bloomberg CityLab. This is because larger vehicles reduce the capacity of driving lanes, according to researchers from the University of Sydney and the University of Hong Kong. “Their findings suggest yet another way in which ‘car bloat’ exacerbates problems that affect everyone, regardless of how they travel,” Zipper writes.

While road safety advocates have been sounding the alarm about large trucks and SUVs for years, the new study adds a new dimension to its assessment of the impacts of larger cars: “They examined whether expanding vehicle size is limiting ‘throughput,’ the maximum number of vehicles that can move through a lane in an hour.” The study found that in Minneapolis and St. Paul, more SUVs reduced the capacity of freeway lanes by almost 10 percent between 1995 and 2019.

Car bloat has other negative externalities that land on society rather than owners, including higher greenhouse gas emissions, faster deterioration of road pavement, reduced on-street parking capacity, and increased tire pollution.

According to the article, “The share of new car sales comprised by SUVs and pickups has leapt from less than one in four during the 1970s to roughly four in five today.” And while larger cars may offer perceived safety benefits to their passengers, a study from The Economist found that the largest 1 percent of vehicles killed 12 people in collisions for every one life saved.