idioms - Is there a more modern way to say "it's a pity"?

Is it okay nowadays to use the phrase "it's a pity" in the everyday conversation in the contexts like in following example:

"Please how do I get to airport?"
"It's a pity, I don't know."

If not, what would be an appropriate equivalent?

Edited (added):

As it follows from answers, this phrase is almost never used by native English speakers. Could you please specify how this phrase sounds for native speaker - as too formal or as archaic or anything else?

Answer

Certainly "I don't know, I'm afraid" is more common in England today. In this particular context, referring to yourself, I would say it sounds more archaic than formal.

"It's a shame" would often be used in other circumstances, e.g. "It's a shame the weather spoiled the event." Today "it's a pity" would be more commonly used in such a circumstance.