Image by John Greenfield

Recent data shows that a road diet in Los Angeles was successful in decreasing speeds and crashes while maintaining a consistent traffic volume. That may not come as a surprise to Strong Towns readers, but it did to the many critics and naysayers in the neighborhood. The Los Angeles Times reports:

In 2013, the Los Angeles Department of Transportation rather famously installed a safety improvement project on Rowena Avenue in Silver Lake, with the goal of saving lives by reducing deadly collisions. The “road diet,” as the project was called, shaved the busy commuter surface street from four lanes to three, partially as a response to the death of Ashley Sandeau, who was struck and killed by a vehicle while attempting to cross the street to see her father.

It's heartening to hear about a city responding constructively and actively to a pedestrian death, instead of with vapid comments calling it "a tragic accident" or meaningless reductions in speed limits.

However, this road diet didn't occur without some pushback. From the article:

Some nearby residents, however, complained that the new street design — though well-intentioned — increased traffic and decreased safety by diverting drivers onto neighboring residential streets. They organized a much-publicized petition calling for the city to provide an alternative solution to its road diet plan.

But the road diet persisted with excellent results. Recent data collection efforts show that average speeds on the street decreased and motor vehicle crashes went down. Unfortunately, speeding and crashes have not been completely eliminated, but it seems the road diet has had an overall positive effect and safety has improved. Most significantly, the data shows that all of this was accomplished while traffic on the street remained at a similar volume. From the article:

We analyzed the average traffic counts on Rowena both before and after the project and found that typical traffic volume was unchanged after the road diet was implemented. [...] These results challenge the perception that Los Angeles is too auto-centric for road diets to work.

This story not only reinforces the value of road diets, it also stresses the need for adequate data collection and analysis both before and after their implementation (or, indeed, the implementation of any project like this). Luckily, road diets are a small-scale intervention—just requiring the re-striping of lanes and changing of signage—with the potential for a big impact. If the intervention hadn't gone well, for whatever reason, returning the street to its original state would be fairly simple (unlike, say, building a new highway in the hopes of decreasing congestion or altering traffic). The data collected in Los Angeles makes plain the positive impact of this road diet, even in an auto-centric city. This is an encouraging message for other towns considering the viability and impact of a road diet.

(Top photo by TransportObserver)

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