Down the pike
From Free Knowledge Base- The DUCK Project: information for everyone
To “come down the pike” is an idiomatic slang expression where “pike” is an abbreviation of “turnpike.” It is extremely common, however, for people to say “come down the pipe” instead, which is clearly a reshaping based on a phonetic error combined with a semantic reinterpretation. Both are metaphors.
Reference: The Eggcorn Database
