A programmable integrated circuit (see FIG. 13) includes a plurality of routing resources including collinearly extending routing wire segments and a test circuit for testing the integrity of the routing wire segments. The routing resource structures include a plurality of unprogrammed antifuses disposed between routing wire segments and a plurality of transistors disposed electrically in parallel with a corresponding respective one of the antifuses. The test circuit has a common node that may be coupled to a selected one of the routing resource structures for testing. In test mode, the test circuit detects whether a current flows through the selected routing resource structure and in response provides either a digital low value or a digital high value on an output node.