Metro unveiled a new master plan yesterday for sidewalks and bikeways, known as WalknBike, which details exactly how much metro Nashville's sidewalk and bikeway network is lacking. The answer is huge: about 1,900 miles of sidewalks.

Sidewalks are important for a number of reasons, but particularly for a neighborhood's walkability — which is more desired now than ever. There's also the matter of safety. As recently as 2014, Metro Nashville was the 15th-most-dangerous region in the country for pedestrians, according to "Dangerous by Design," a report by Smart Growth America, though the area had dropped out of the top 20 by 2016.

Metro's plan doesn't call for thousands of miles of new sidewalks, but highlighted 91 miles it deems the most critical. The cost of building even that much would be $550M. The plan also calls for $41M worth of high-priority bicycling projects.

All that might sound daunting, but much progress has already been made. In 2003, the county had only 727 miles of sidewalks, and 10 miles of bikeways. Now it has about 1,130 miles of sidewalks and 250 miles of bikeways.