Add array to route.data

If I add an array to route data, I get open/close square brackets (escaped) in the url

example:
route.data.arr =["one", "two"]

changes the route data to:
?arr%5B%5D=one&arr%5B%5D=two

how can I do this properly so those square brackets are omitted and the url looks like the following?
?arr=one&arr=two