John and Kitty Hahn have been on the road now for 16 years.

They started their retirement in their 50s as RV enthusiasts. But after a road trip from their former home in South Elgin, Ill. to Alaska with some friends, they were hooked.

The couple became full-time RV residents and sold their home to one of their three children.

Like the Browns, the Hahns frequently volunteer at sites organized by the NOMADS, where members roll up in RVs ready to help with disaster recovery, home repairs and other work. They spend roughly half of their year helping at 3-week volunteer projects, which typically come with a free place to park their RV.

Diesel fuel and parking costs, as well the occasional repair, take up the largest chunk of the couple's budget.

"When you live in an RV, you can't buy much other than food," said Kitty.