A “sneckdown” is what you call the piles of snow that remain when drivers have carved out tracks after a winter storm. These patterns on the street show where there’s plenty of space to expand the sidewalk or add a bike lane.

In a 2014 blog post, Jon Geeting highlighted more than a dozen of them along a single Philadelphia street. Geeting photographed sneckdowns on Passyunk Avenue and outlined them in a bold green. It turned out to be a highly effective way to communicate the idea — the post was shared around the world.

It worked so well that one of the sneckdowns Geeting highlighted is now a permanent fixture on Passyunk Avenue, where the city cast it in concrete as a pedestrian island (above).

After Geeting’s blog post when viral, Sam Sherman at the Passyunk Avenue Revitalization Corporation took up the cause with the city’s streets department. Here’s the result:

“It’s such a huge improvement for pedestrian safety in this area,” said Geeting. “I’m hoping this success will be contagious and we’ll soon see more pedestrian improvements at the rest of the intersections from the post.”