The phrase "roller blades" refers to a type of inline skates. They are similar to regular ice skates, but with wheels attached beneath. When you wear them, you can glide or skate on smooth surfaces like roads and sidewalks. Full definition
If kids take chances when they get on the ice or on roller blades [for the first time], then they'll take chances in the classroom. (educationworld.com)
For some people, this is a pair of walking shoes; for others, a bicycle or pair of roller blades. (money.stackexchange.com)
(It also includes locations for bike and roller blade hire for lively ways to move around town). (visitcalifornia.com)