As Austin grows, walkability is a must.

This spring, Redfin named Austin the second most walkable city in the state -- behind Dallas. But there are thousands of miles of missing sidewalks and the city is determined to fill in the gaps.

Nathan Hanson visits Jollyville Road three to four times a week.

"I come here just for exercise - jogging and things like that," Hanson said.

He says at times it can be difficult .

"There's quite a few areas that are hard to walk through," Hanson said.

Large spaces in the sidewalk scatter Jollyville Road, but next month the city plans to fix this.

"This project is focused on filling in the gaps," John Eastman with the City of Austin Public Works Department said.

The city will use $330,000 from a 2012 transportation bond to fill in the gaps from Balcones Woods Road to Duval Drive, hoping to be done in four months.

It turns out this is just a small portion of the problem.

"Approximately half of the frontages in Austin don't have sidewalks," Eastman said.

Which amounts to almost 2,400 miles of needed work and an estimated cost of $1.46 billion. City representatives say it's because the city stopped building sidewalks from about 1940 until 1980.

"In the 1980s there was a growing recognition that people were having difficulty accessing transit - walking around their neighborhoods and so sometime in the 1980s the city of started requiring sidewalks as part of new development," Eastman said. So they started playing catch up on old development.

Focusing on areas like Jollyville, the city hopes to make it easier for people to get around.

For more information on Austin sidewalks click here.